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Wednesday, December 31, 2014

EAB is confirmed in Dakota County

Jeffrey Hahn, Extension Entomologist

(The following information is taken from a December 23, 2014 newsletter from the Minnesota Department of Agriculture)


Jeff Hahn, Univ. of MN Extension

Photo 1: Ash trees marked for removal due to EAB.

The Minnesota Department of Agriculture (MDA) confirmed an emerald ash borer (EAB) infestation in Dakota County. EAB was found in an ash tree in Lebanon Hills Regional Park in the city of Eagan, just north of the border with Apple Valley. The infested tree was detected through a routine visual survey of ash trees currently being conducted by the MDA. This survey is designed to find EAB in counties bordering the Ramsey and Hennepin County quarantine area.

Dakota County becomes the sixth county in Minnesota to confirm EAB. Additionally, EAB has also been found in Hennepin, Ramsey, Houston, Winona, and Olmsted (which was just confirmed this August) counties. These counties all have a state and federal quarantine established. The quarantine is in place to help prevent EAB from spreading outside a known infested area. It is designed to limit the movement of any items that may be infested with EAB, including ash trees and ash tree limbs, as well as all hardwood firewood.

This is especially important for Minnesota as there are approximately one billion ash trees present in this state. And all are susceptible to this invasive beetle. It is critical that people be aware of and follow the quarantine to minimize the spread of EAB. The biggest risk of spreading EAB comes from people unknowingly moving firewood or other ash products harboring larvae.

Every Minnesotan can help prevent EAB from spreading by taking the following steps:

• Don't transport firewood. Buy firewood locally from approved vendors, and burn it where you buy it;

• Be aware of the quarantine restrictions. If you live in a quarantined county, be aware of the restrictions on movement of products such as ash trees, wood chips, and firewood.

• If you think you have seen an infested ash tree, go to www.mda.state.mn.us and use the "Do I Have Emerald Ash Borer?" checklist or contact MDA's Arrest the Pest Hotline by calling 888-545-6684 or emailing Arrest.The.Pest@state.mn.us to report your concerns.

For more information about EAB, see the University of Minnesota Extension publication, Emerald ash borer in Minnesota.

The original MDA news release can be found here.

Tuesday, December 9, 2014

Spotted lanternfly is now in U.S.

Jeffrey Hahn, Extension Entomologist

A new invasive insect species from Asia, the spotted lanternfly, Lycorma delicatula, was discovered last month in Pennsylvania. Despite its name, this insect is not a true fly but is actually a type of planthopper which is related to aphids, leafhoppers, cicadas and similar insects. 


Lawrence Barringer, Pennsylvania Dept of Agriculture

Photo 1: Spotted Lanternfly. Note spots on most of the wing and the lacey pattern on the wing tips.

A spotted lanternfly is a large insect, measuring about one and a half inches long. It is very distinctly colored and patterned. About 2/3 of the forewing is a light gray with small oval, black spots. The wing tips have a series of tiny rectangular black spots that give it a lacey appearance. The hind wings, when exposed, are brightly colored orange-red, black and white.

There are some native insects that could be confused with a spotted lanternfly, especially tiger moths and underwing moths which also can have red hind wings. However, moths are much better fliers compared to a spotted lanternfly. Moths also do not jump while a spotted lanternfly (and other planthoppers) are good jumpers.

The spotted lanternfly is known to attack about 65 different plant hosts in Korea, especially tree of heaven and grapes. It is also known to attack plants in the same genera as apple, willow, oak, lilac, rose, maple, poplar, and pine. Spotted lanternflies (like other planthoppers) damages plants by using its needle-like mouthparts to feed on plant sap.

It is unclear what the potential for damage would be if this insect becomes established in Minnesota. While there are many plants on which they are known to feed that are present in this state, a key to their ability to infest an area seems to hinge on the presence of tree of heaven which is not a native to Minnesota. In fact only one specimen is presently known to occur in the state. The question then is whether this insect could thrive on other plants. Time will tell.

If you find an insect that you believe is a spotted lanternfly, report it to the Minnesota Department of Agriculture on their Arrest the Pest line by calling 1-888-545-6684 (voicemail) or e-mailing them at Arrest.the.Pest@state.mn.us.

Click here for more information on spotted lanternflies.  

Tuesday, December 2, 2014

December 1st 2014 Issue of Yard and Garden News

In this issue:

Pine Wilt

Mode of Action of Neonicotinoids


Mode of action of Neonicotinoids

Karl Foord, Extension Educator - Horticulture

Insecticides

Insecticides can be characterized by the way in which they disrupt important biochemical functions. Many insecticides target the nervous system of insects by impairing the control of neural transmission. This can be done by disabling the system, and shutting it down. However, the majority of neural insecticides put the system in a continual state of ON giving the organism no opportunity to stop neural transmission. This results in uncontrolled and uninterrupted nerve firing. The insect that is exposed to such chemicals exhibits tremors, hyperactivity and convulsions. Sublethal doses of these chemicals can impair proper functioning behaviors such as flight orientation, and feeding while greater doses lead to a quicker death.

Normal neural transmission

A normal neural transmission proceeds down the nerve axon which splits into branches and eventually into smaller branches called dendrites. The dendrites of one nerve cell pair with the dendrites of other cells. The space between these two dendrites is call a synapse (Exhibit 1).

The electrical signal of the nerve is translated into a chemical message made up of so called neurotransmitter molecules. These molecules diffuse across the synapse and attach to receptor molecules on the dendrites of the paired nerve (Exhibit 2). The chemical message is translated back into an electrical message that then travels down this nerve cell's axon, and the neurotransmitter molecules are disassociated from the receptor molecules by an enzyme.

Neonicotinoid disruption of neural impulse

Neonicotinoid molecules enter the neural synapse and irreversibly attach to the receptors on the receiving neuron (Exhibit 2). The neurotransmitter enzyme cannot remove the imidacloprid molecule and the receptor is thus continuously active. The organism has lost control of neural transmission and either loses function or dies.

Monday, November 10, 2014

Pine Wilt



USDA Forest Service

Photo 1: Scots pine killed by pine wilt

Dan Miller, MN Landscape Arboretum

Two mature Scots pines (Pinus sylvestris) at the Minnesota Landscape Arboretum started showing tan-colored needles at the end of the summer this year and by late September both trees were dead. When one of the trees was being removed, Assistant Gardener Mike Walters noticed a blue stain in the sapwood of the tree and from his previous experience with a tree care company in southeastern Iowa; he suspected the tree had been killed by nematodes. Cross-sections of the blue-stained wood were soaked in water and nematodes, microscopic roundworms, could be observed with a dissecting microscope. A sample was then sent to the University of Minnesota Plant Disease Clinic and they confirmed the presence of the pine wood nematode (Bursaphelenchus xylophilus). This nematode is the primary cause of pine wilt disease.


Dan Miller, MN Landscape Arboretum

Photo 2: Cross section of a Scots pine infected with blue stain fungus
Pine wilt disease is an interesting and complex disease. Two insects, the nematodes, and a fungus are all involved. The nematodes are transmitted by the pine sawyer beetle (Monochamus spp.). The adult pine sawyers feed on the young shoots of pine trees and even though they don't cause much damage to the tree, the feeding wounds create entry points for the hitch-hiking nematodes. When the nematodes enter the tree they feed on the cells surrounding the resin ducts causing resin to leak and plug the water transport system of the tree. As the tree is weakened and becomes stressed, bark beetles are attracted. When the bark beetles bore into dying pines, blue-stain fungi living in the beetles also enters the tree. This fungus provides another food source for the nematodes so their numbers multiply even faster.


Natasha Wright

Photo 3: White spotted pine sawyer; the beetle that transmits the pine wood nematode
Pine wilt disease was first reported in Minnesota by Dr. Robert Blanchette (University of Minnesota Professor of Plant Pathology) in the early 1980s but the nematode is believed to be native to North America. Pine wilt disease occurs most commonly in stressed nonnative trees. In the Midwest, 90 percent of the trees killed by pine wilt are Scots pine. The disease occasionally appears in Austrian (Pinus nigra), mugo (Pinus mugo), and Japanese red (Pinus densiflora) as well. Native pine species are usually not susceptible. In most cases, only trees greater than 10 years old are attacked. Once the tree is attacked, it dies within a few weeks.


Y. Mamiya

Photo 4: Pine wood nematode inside the resin canal of a pine tree
At this point management options are limited. Insecticides and nematicides have not proven to be practical or effective. The best strategy is sanitation. Dead trees should be removed in the fall or early spring before the adult pine sawyers emerge and should be burned, buried, or chipped. Scots pines are not recommended for new plantings.

Monday, November 3, 2014

November 3rd 2014 Issue of Yard and Garden News

In this issue:

Fruits and Vegetables

Millipedes in vegetables

Lawns and Landscapes

The BEST Crabapples for Minnesota: Height, Fruit, Scab Resistance and Finally: Flowers - Part I


The BEST Crabapples for Minnesota: Height, Fruit, Scab Resistance and Finally: Flowers - Part II


The BEST Crabapples for Minnesota: Part III- Table & References

Turf and Bees: What's the buzz on pesticides in lawns?

WCCO "Smart Gardens" Radio Show - October 18 & 25, 2014


Pest Management

Forest Pest Workshops Scheduled in SE Minnesota

Don't worry about snowfleas


The BEST Crabapples for Minnesota: Part III- Table & References

Mary H. Meyer, extension horticulturist and professor, University of Minnesota


Mary Meyer

Table 1: BEST Crabapples for Minnesota

References and Further Reading:

Beckerman, J., J. Chatfield, and E. Draper. 2009. A 33-year Evaluation of Resistance and Pathogenicity in the Apple Scab-crabapples Pathosystem. HortSci. 44(3):599-608.

Chatfield, J. A. E. A. Draper, and B. Cubberley. 2010. Why Plant Evaluations Matter. American Nurseryman 210(9):10-15.

Draper, E. K., J. A. Chatfield, and K. D. Cochran. 2005. Marvelous Malus--Ten Crabapples Worthy to Know, Show, and Grow. Brooklyn Botanic Garden. Accessed October 6, 2014.

Green, T. L. 1995. Results of the national crabapple evaluation program. Accessed online October 3, 2014.

Green, T.L. 1996. Crabapples--When you're choosing one of those apple cousins, make flowers your last consideration. Amer. Horticult. 75:18-23.

Guthery, D.E. and E.R. Hasselkus. 1992. Jewels of the landscape. Amer. Nurseryman 175(1):28-41.
Iles, J. 2009. Crabapples..... With No Apologies. Arnoldia. Accessed online October 10, 2014.

Koetter, R. and M. Grabowski. 2014. Managing apple scab on ornamental trees and shrubs. Accessed online October 10, 2014.

Romer, J., J. Iles, and C. Haynes. 2003. Selection Preferences for Crabapple Cultivars and Species. HortTechnology 13:522-526.

Schmidt, J. Frank and Sons. 2014. Crabapple Information Chart. Accessed online October 8, 2014.

The BEST Crabapples for Minnesota: Height, Fruit, Scab Resistance and Finally: Flowers - Part II

Mary H. Meyer, extension horticulturist and professor, University of Minnesota


Mary Meyer
Photo 1: Adirondack close-up

Mary Meyer
Photo 2: Adirondack - whole tree

Mary Meyer
Photo 3: Beverly close-up

Mary Meyerd
Photo 4: Beverly - Whole tree

Mary Meyer
Photo 5: Bob White close-up

Mary Meyer
Photo 6: Bob White - whole tree

Mary Meyer
Photo 7: Donald Wyman - whole tree

Mary Meyer
Photo 8: Firebird close-up

Mary Meyer
Photo 9: Firebird - whole tree

Mary Meyer
Photo 10: Louisa close-up

Mary Meyer
Photo 11: Louisa - whole tree

Mary Meyer
Photo 12: Pink Spires close-up

Mary Meyer
Photo 13: Pink Spires - whole tree
Which one would I plant in my yard? Anyone from this list, but something in the name 'Professor Sprenger' does resonate with me! It is a lovely tree that greets visitors on the Snyder Terrace at the Arboretum. Others you can see easily at the Arboretum are: 'Donald Wyman' planted in mass in the first parking lot bay across from the Oswald Visitor Center; 'Adirondack' marks the entrance to the espalier in the Cloister Herb Garden; 'PrairiFire' makes the double allée at the Sensory Garden, 'Pink Spires' flanks the entry to the new Green Play Yard at the Andrus Learning Center, and two 'Prairie Maid' trees fill an island in the staff parking lot.

The BEST Crabapples for Minnesota: Height, Fruit, Scab Resistance and Finally: Flowers - Part I


Mary Meyer
Photo 1: Prairie Maid close-up

Mary Meyer Photo 2: Prairie Maid - whole tree

Mary Meyer
Photo 3: PrairiFire close-up

Mary Meyer Photo 4: PrairiFire - Whole tree (left) Sargentii espalier (right)

Mary Meyer
Photo 5: Professor Sprenger close-up

Mary Meyer
Photo 6: Professor Sprenger - whole tree

Mary Meyer
Photo 7: Red Jewel close-up

Mary Meyer
Photo 8: Red Jewel - whole tree

Mary Meyer
Photo 9: Royal Raindrops close-up

Mary Meyer
Photo 10: Royal Raindrops - whole tree

Mary Meyer
Photo 11: Sargentii close-up

Mary Meyer
Photo 12: Sugar Tyme close-up

Mary Meyer
Photo 13: Sugar Tyme - whole tree
Mary H. Meyer, extension horticulturist and professor, University of Minnesota

This summer I was asked so many times "What is wrong with my crabapple?" that I started LOOKING anew at crabapples. 2014 was a banner year for apple scab, discoloring the foliage and causing premature leaf and even fruit drop. Affected plants looked dormant, or as many homeowners feared, dead. Apple scab can weaken trees, but rarely is fatal. Scab may allow secondary organisms to attack the tree and can decrease its winter hardiness, so it is best to purchase a scab-resistant crabapple. WHICH crabapples are resistant to scab, is complicated as the newest study (Beckerman et al, 2010) shows a new strain of this disease may now infect previously resistant cultivars. Additionally, we tend to think only about the FLOWERS on crabapples, and especially LOVE the showy pink or red flowers that are unfortunately often more susceptible to scab.

I recommend the first criteria for selecting a crabapple should be the ultimate SIZE, height and shape of the plant, followed by scab resistance, fruit, and finally the flowers. It is a misconception that crabapple fruit is messy: the small colorful fruit (5/8 inch or less) is a valuable food source sought by birds throughout the winter, and adds color and interest for many months.

Late fall is an ideal time to walk the crabapple collection at the Minnesota Landscape Arboretum and pick your favorite, because you can easily select scab resistant plants with clean, healthy leaves. Additionally, you can evaluate the fruit which varies widely in color and can last for MONTHS, easily six or even eight months. Remember that crabapple flowers last only for DAYS, perhaps a week. Why not select a crabapple for healthy leaves, and attractive fruit and just let the flowers be an added bonus?

From endless lists of hundreds of crabapples, the short list below was developed based on fall appearance with clean foliage at the Arboretum. Additionally, these plants are also top recommendations from long-term research trials conducted at the Ohio State University (their Crablandia field plots); Morton Arboretum, Illinois; Purdue University, Indiana; and the multi-state National Crabapple Trials.

I propose these 13 crabapples as "the best" for Minnesota. If your favorite is not here, let me know! All of the plants listed show good to excellent resistance to apple scab with an asterisk * for those showing some susceptibility to the new apple scab strain now in the Midwest. 'Red Splendor' is a showy red-pink prolific flowering crabapple that originated in Minnesota, however, it is susceptible to scab, needs plenty of space due to its large size and can be defoliated and defruited in mid-summer due to scab.

Which one would I plant in my yard? Anyone from this list, but something in the name 'Professor Sprenger' does resonate with me! It is a lovely tree that greets visitors on the Snyder Terrace at the Arboretum. Others you can see easily at the Arboretum are: 'Donald Wyman' planted in mass in the first parking lot bay across from the Oswald Visitor Center; 'Adirondack' marks the entrance to the espalier in the Cloister Herb Garden; 'PrairiFire' makes the double allée at the Sensory Garden, 'Pink Spires' flanks the entry to the new Green Play Yard at the Andrus Learning Center, and two 'Prairie Maid' trees fill an island in the staff parking lot.

There is an amazing variation that exists in these tough plants. A crabapple that grows well in Ohio, may not show the same disease resistance to apple scab here in Minnesota. The weather and climate makes a difference. Touring the famous crabapple collection at the Arboretum and the newer plantings in the display gardens can give you a first-hand look at how the plants grow in our climate. Ideally, we would annually rate crabapples three times: for foliage and fruit in September and October; for winter interest and fruit (bird food) in January; and flowering in May. Look for yourself at a garden center or the Arboretum, so you can decide which form and fruit is best for your garden and landscape.

Friday, October 31, 2014

Millipedes in vegetables

Jeffrey Hahn, Extension Entomologist


Jerry Wenzel

Photo 1: Despite the circumstantial evidence, the millipedes did not damage this carrot; they are taking advantage of previous damage.

A couple of home gardeners encountered millipedes in some of their vegetables during October. In one case they were in a few potatoes, in another instance they were infesting a carrot. There was concern whether the millipedes were attacking healthy vegetables. Fortunately, the millipedes were not causing damage in the garden. They have weak mouthparts and are only capable of feeding on decaying organic matter. It is possible for them to feed on plants that have already been damaged but they are not attacking healthy plants.

A 2012 research article in the Journal of Applied Entomology looked at the potential of millipedes and wireworms to attack carrots (also sweet potatoes). They found the presence of the millipedes was associated with wireworm damage to carrots. The millipedes themselves were not causing damage but were there as a result of preexisting wireworm injury. That is also what is probably happening with the presence of millipedes in the potatoes. The millipedes were not damaging the tubers but were there because of other damage (probably wireworms).

Fortunately wireworm damage is not common in home gardens and this kind of injury (as well invasion by millipedes) should not be a problem very often.

Thursday, October 30, 2014

Don't worry about snowfleas

Jeffrey Hahn, Extension Entomologist


Diane Peterson

Photo 1: These strange black lines are composed of large numbers of snowfleas

A couple of homeowners discovered an odd situation in their lawns during mid to late October. From a distance, they could see long, black lines in the grass. Upon closer inspection, they discovered that the black lines were actually due to many tiny insects. Examining the insects under magnification revealed that they were snowfleas, a type of springtail.

Springtails get their name because of their ability to jump. They feed on decaying organic matter as well as fungi, pollen, and algae. They are very abundant insects but because of their small size and that they are usually found in leaf litter, soil, and other generally hidden places, people do not usually notice them. Until, that is, they occur in large numbers.


Jeff Hahn, Univ. of Minnesota Extension

Photo 2: Snowfleas are most commonly seen on top of snow.

Snowfleas are particularly interesting because they are cold tolerant. They are typically seen during late winter and early spring as the snow starts to melt and they congregate, often in large numbers.  Fortunately, whether you see snowfleas now or on top of snow later, they are harmless to turf and should be ignored. They will eventually go away on their own.

Monday, October 27, 2014

WCCO "Smart Gardens" Radio Show - October 18 & 25, 2014

Thanks for listening!

We aren't always able to answer everyone's texted questions on the air, so we try to post a few along with answers here in the Yard & Garden News blog. Remember that you can always visit the U of M Extension Garden website for loads of gardening resources. And feel free to share your gardening stories here by clicking on "Leave a comment" above.
Hope you join us and our host Denny Long every Saturday, 8-9am, on WCCO Smart Gardens and happy gardening!

American Bittersweet 'Autumn Revolution': Thanks to to listeners last week who shared via text the bittersweet cultivar 'Autumn Revolution' (Celastrus scandens 'Bailumn') developed by Bailey Nurseries, Newport, MN. This bittersweet has 'perfect' flowers - male and female parts on each flower - unlike the species bittersweet which has separate male and female flowered plants.

Overwintering perennials in containers: Perennials are best overwintered planted in the soil. However, they are used in container plantings and some listeners have asked how to overwinter them. There's no guarantee, but certainly worth a try. The goal is to allow the plant to gradually go dormant as it would in the ground, but protect the roots from cold air as they would be in the soil. Try overwintering these plants by tipping the container over onto the soil and covering in leaf mulch, wood mulch or straw. Or try placing the container in a cool location such as a cellar or heated garage (about 40-50 degrees F.) If it's not too much work, you could also dig a hole in your garden or compost pile and bury the container up to its rim, covering the top of the soil with straw or leaf mulch. Do not water them, but allow them to go dormant. When the weather warms up and you start to see plants emerging in your garden,  tip the container over / move the container out into the sun and start watering.

Do pileated woodpeckers cause oak wilt? This was the first time someone has asked me this - and I truly never thought about it! Oak wilt is spread overland by sap-feeding beetles, and underground by infected roots grafting onto healthy roots. I could find nothing that indicated woodpeckers or other birds spread oak wilt. As home owners, be alert to the signs and symptoms of oak wilt, and avoid pruning oaks April - June or whenever you see the active beetles. Remember that dates provided are recommendations - you still need to be vigilant in your yards and gardens. For more on oak wilt: MN DNR 

Dividing perennials: If you are considering dividing your perennials - including hardy hibiscus (Hibiscus moscheutos) as asked by one listener, here is a terrific publication / chart Dividing Perennials you can use as a reference. Notice that there are some perennials that should not be divided - and Hibiscus moscheutos should be divided every 10+ years according to the above publication. Make sure your planting location is large enough for your selected plant to grow to full maturity.

Must I wait till freeze to dig calla and canna bulbs? Calla and canna are summer-blooming tuber-like rhizomes and really quite stunning plants. However, unlike bulbs like tulips and daffodils that require cold treatment, calla and cannas do not survive our winter temperatures and must be dug in the fall and re-planted each spring. Dig them now as you don't want to risk the rhizomes freezing. According to our Extension publication Calla and Canna Lilies: "They bloom mid-summer to frost. In the fall, dig up the rhizomes, cut the stems back to 2-3 inches, and let them dry. Leave them in a box in a cool part of the house where they will not freeze, such as a basement where the temperatures range between 40-50 degrees. Every few years, the rhizomes may be divided. When dividing, each piece must have an eye or growing point on it. Let the cut-up rhizomes dry for a few days before planting them."

Thursday, October 23, 2014

Turf and Bees: What's the buzz on pesticides in lawns?

By Ian Lane, Graduate Research Assistant

If you have been paying attention to the news lately, you know that bees have been making headlines. News outlets have done an amazing job of helping scientists sound the alarm on unsettling declines in bee pollinators. While we have good evidence for declines in honey bees and some of their cousins, the bumble bees, the cause of this decline is hard to pinpoint. Current thinking in the scientific community puts the decline down to a number of interacting factors, including reduction in stable food sources, introduction of bee diseases, and the irresponsible use of insecticides. While it's difficult to tease apart how these factors interact, we do have some good knowledge about how lawns fit into this theoretical framework.


Sam Bauer

Photo 1: White clover and dandelion can provide great early season forage for pollinators in lawns


Herbicides


Lawns are home to a number of weeds that are the bane of homeowners. While our gut reaction may be to reach for a herbicide, it's worth noting that many weeds actually can provide high quality forage for bees. Two of the most important lawn forage plants are the common dandelion (Taraxacum officinale) and Dutch white clover (Trifolium repens). Dandelions are one of the earliest, and often only, blooming flowers of spring. This early source of pollen and nectar is essential to overwintering honey bee colonies as they begin the process of raising new workers. White clover is another spring bloomer (though not as early) that provides highly nutritious pollen throughout the year. While the exact nature of bee's relationship with these flowers isn't widely studied, recent research at the University of Kentucky sought to characterize the types of bees visiting dandelions and clover. They found surprising diversity on white clover, including a number of at risk bumble bees (Larson et al. 2014). Similar preliminary research here at the University of Minnesota confirms many of their findings.

There may also be some solutions for homeowners looking to control weeds but leave clover in their lawn. One common herbicide known as 2,4-D is effective on many broadleaf weeds, but generally ineffective on clover. Small demonstration trials at the University of Minnesota confirm that 2,4-D has relatively low action on clover but is relatively effective against other weeds.

Insecticides


The another type of pesticide that can make a big impact on bees are insecticides . Much of the recent attention on pollinators has focused on a class of insecticides known as the neonicotinoids. Neonicotinoids are used in turf to help control a number of insect pests, most importantly grubs. They work by "dissolving" into the irrigation water or rain, which is then taken up by the plant and becomes part of the leaf and root tissue. This ensures that any insect munching on the tissues of your grass gets a lethal dose, and your lawn stays green. While bees would never have a reason to take a bite of your grass, your helpful lawn weeds are a different story. It turns out that not only do these insecticides move into plant leaves and roots, but the nectar and pollen of the flowering weeds as well.

Many studies have looked to see if neonicotinoids applied to lawns full of clover have negative effects on bumblebee colonies. The researchers in Kentucky do this by getting a colony of the commercially available common eastern bumble bee (Bombus impatiens), placing it on a patch of flowering clover that is treated with a neonicotinoid, then caging them so they are forced to forage on the treated clover. These experiments are always accompanied with a similar set-up but on a non-treated patch as a point of comparison. Here again the University of Kentucky has been leading the way with a study published in 2002 (Gels et al. 2002) that found if imidacloprid (a type of neonicotinoid) was applied to flowering turf without any post application irrigation that bumble bee colonies suffered worker weight loss, increased worker death, and sluggish behavior. However, if irrigation was applied directly following these imidacloprid applications, no negative responses were seen.

Similar responses were seen in a study investigating clothianidin, another type of neonicotinoid (Larson et al. 2013). Bumble bee colonies that were confined over patches of flowering clover, and that had the high label rates of clothianidin applied to the turf, saw dramatic effects on the number of workers, new queens, as well as total colony weight when compared to control colonies. The effects of irrigation were not part of this study, but when clover nectar from nearby sights that had been applied with clothianidin were sampled, they found high amounts of the neonicotinoid. This study's main aim was to compare clothianidin to a new chemistry of insecticides called anthranilic diamide (specifically chlorantraniliprole). This new class of chemical had seemingly no adverse effects on bumble bee colonies when compared to the controls. While there is more research to be done, this is a promising alternative to neonicotinoids for insect control in turf. You can currently purchase chlorantraniliprole for use on residential and commercial turf, and trade names include "Scott's Grubex" or Syngenta's "Acelepryn".

While urban landscapes and lawns are only one part of a very large system, they are nevertheless an important part of a vast majority of people's lives. Promoting animal diversity in urban landscapes, be it pollinator or other, helps improve important issues related to stormwater runoff (rain gardens and buffer strips) and urban agriculture (pollination and biocontrol services) and also enriches everyday life through learning opportunities and aesthetic value. Even the smallest effort, such as leaving some weedy flowers or choosing a safer insecticide, may make a difference.

Stay Informed


A new series on pollinators is being offered by the University of Minnesota Landscape Arboretum. "Pollinators: What you need to know and how to make a difference" is a 3-part series focusing on: 1) Plants and People, 2) Pesticides and Other Problems, and 3) Policies and Politics.

The Minnesota Turf and Grounds Foundation will be offering a 1-day session on Super Tuesday of the Northern Green Expo, January 13th, 2015. "Bee Aware: The importance of pollinators in the landscape" will feature expert presenters discussing real world issues surrounding pollinators, as well as practical strategies to promote them in the landscape. Stay tuned to www.mtgf.org as this program develops.

Works Referenced


Gels, J. A., D. W. Held, and D. A. Potter. 2002. Hazards of Insecticides to the Bumble Bees Bombus impatiens (Hymenoptera : Apidae ) Foraging on Flowering White Clover in Turf. J. Econ. Entomol. 95: 722-728.

Larson, J. L., A. J. Kesheimer, and D. A. Potter. 2014. Pollinator assemblages on dandelions and white clover in urban and suburban lawns. J. Insect Conserv. 18: 863-873

Larson, J. L., C. T. Redmond, and D. A. Potter. 2013. Assessing insecticide hazard to bumble bees foraging on flowering weeds in treated lawns. PLoS One. 8: e66375.

Sunday, October 12, 2014

Forest Pest Workshops Scheduled in SE Minnesota

Jeffrey Hahn, Extension Entomologist

Rochester will host two workshops in response to the recent discovery of emerald ash borer (EAB) in Olmsted County. The first will be a Forest Pest First Detector workshop to be held on Wednesday, November 5th from 9 AM - 3:30 PM. The cost is $40 (lunch included). In addition to EAB, other pests to be discussed include gypsy moth, Asian longhorned beetle, thousand canker disease, and Oriental bittersweet.



Jeff Hahn, Univ. of Minnesota Extension

Photo 1: Learn about emerald ash borer and other forest pests at a First Detector workshop.

The Minnesota Forest Pest First Detectors training program is designed to help identify the occurrence of Emerald Ash Borer and other forest pests in Minnesota. First Detectors are the front line of defense against likely infestations. Meeting, working with and educating the public about exotic forest pests are key activities of Forest Pest First Detectors.

Everyone is welcome to attend - even if you do not wish to become a Forest Pest First Detector! Anyone with a background in tree or forest health should consider becoming a Forest Pest First Detector.

Forest Pest First Detectors must complete online training modules before attending the one-day Forest Pest First Detector training and commit to being available and involved with the program after completing the training. Involvement includes being accessible to the public, willing to conduct site visits if necessary, report forest pest-related activities, protect confidential information, and notifying organizers of current contact information.

Visit My Minnesota Woods for more information.

To register, visit here.

An Ash Management for Woodland Owners workshop is scheduled on Wednesday, November 12 from 9 AM to noon. Ash Management for Woodland Owners will include information about EAB and managing your woodland in the era of EAB. An outdoor field tour will follow an indoor presentation. This workshop is intended for woodland owners. There is a $20 fee to attend this workshop.

To register for one or both classes go to this site.

Thursday, October 2, 2014

October 1st Issue of Yard and Garden News

In this issue:

Don't Confuse Yellowjackets and Bees

Late Fall Vegetable Gardening - Pest Management

Ground nesting BEES Colletes Part I: Building a nest

Ground nesting BEES Colletes Part II: Foraging

Ground nesting BEES Colletes Part II: Foraging

Karl Foord, Extension Educator - Horticulture

Watching these bees leave their nest and returning covered with pollen was quite enjoyable.

I will let the video speak for itself. Please enjoy. Colletes foraging.

Ground nesting BEES Colletes Part I: Building a nest

Karl Foord, Extension Educator - Horticulture

One of our early emerging vernal native bees is in the genus Colletes. These bees are commonly called plasterer bees, cellophane, or polyester bees. This is because the bee builds an underground nest and then paints/applies/lines her nest with a cellophane-like plastic material secreted from an abdominal gland. The bee applies this material with her two-lobe tipped tongue. This secretion helps protect the developing bees from fungal disease and acts as a waterproof barrier. It is so effective that ground-nesting species can occupy areas prone to flooding.

I photographed a Colletes bee digging a nest. The nest took several hours to dig which I videoed and then cut out much of the inactivity to create a 5 minute video.

One of today's landscaping rules-of-thumb is to cover bare soil with mulch to both prevent erosion and discourage weed encroachment. This makes sense, however should we reconsider this practice in light of our need to provide nesting habitat for native bees? Perhaps there are areas in the garden or proximal to the garden which could be left open and undisturbed.

Though not specifically stated open soil areas were considered a sign slovenliness, something not tolerated in my upbringing environment. Somewhat along the line of "There are no dirty or lazy Zimmerman's". Something my maternal grandmother used to say.

The two main threats to most pollinators include habitat loss and pesticide use.

You can create a welcoming environment to ground nesting bees by doing the following:

1. Leave bare patches of ground in your garden or yard to help provide nesting sites. It may look unkempt but it is unkempt with a purpose.

2. Plant a variety of bee friendly nectar and pollen rich native plants. A good place to start is "Plants for Minnesota Bees" by Elaine Evans.



Elaine Evans

Photo 1: Plants for Minnesota Bees (front)





Elaine Evans

Photo 2: Plants for Minnesota Bees (back)

3. I have decided that to the extent possible I would rather watch what is happening in my garden then attempt to kill certain pests with the high likelihood of killing beneficials. My worst garden pest is the four-lined plant bug which attacks my anise hyssop. Given how I feel about anise hyssop (possibly the best bee plant I have encountered) you can imagine how motivated I would be to remove these pests. I have controlled them to my satisfaction by clapping my hands on the leaves where I see the bugs. The leaves tolerate this much more than the four-lined plant bugs. Avoiding the use of synthetic pesticides in your garden and on your lawn is recommended.

Friday, September 26, 2014

Late Fall Vegetable Gardening - Pest Management

Cindy Tong, UMN Extension Specialist


UMN Dept. of Entomology

Photo 1: Adult Colorado Potato Beetle

Take care of those pests, or they might just come back next year! Two of the recurring pests common to most gardens are weeds, weeds, weeds and Colorado potato beetles. Weeds are plants that have evolved successful strategies for competing against other plants, like developing spreading rhizomes (think Creeping Charlie) or lots and lots and lots and lots of small seeds (amaranth). If your garden has weeds that are blooming or forming seeds, it's worthwhile to take them out even now. Otherwise, those lots and lots and lots and lots of seeds will drop to the ground and stay in the soil, making up a big part of the seedbank, from which future generations of weeds will grow.

Colorado potato beetle adults may still be laying eggs, even if your potato plants are going to be dug up soon. Even if there soon won't be anything for those beetles or their young to eat, it's still worthwhile killing the adults because they can overwinter in nearby brush, and then come back out next spring!

Wednesday, September 17, 2014

Don't Confuse Yellowjackets and Bees

Jeffrey Hahn, Extension Entomologist



Jeff Hahn, Univ of MN Extension

Photo 1: Yellowjackets are black and yellow with few hairs and construct nests made of a papery material.

As the summer winds down, people have been commonly finding insects nesting in and around their homes. There can be confusion whether people are seeing yellowjackets or honey bees. There is tendency for people to call all stinging insects "bees". This has been compounded with the recent attention in the media on honey bees so people are thinking about them even more. While yellowjackets and honey bees both can sting, they have very different biologies. At this time of the year, people are most often seeing yellowjackets.



Jeff Hahn, Univ of MN Extension

Photo 2: Honey bees are brown and black and hairy. Don't confuse them with yellowjackets.

A yellowjacket is about ½ inch long (this can vary some), black and yellow, and relatively slender with few hairs. A baldfaced hornet, actually a kind of yellowjacket, is a little larger, about 5/8th inch long, and mostly black. Honey bees are about ½ inch long brown and black, relatively slender but have more hair.

Yellowjackets construct their nests from a papery material with the combs surrounded by an envelope, while honey bees produce combs made of wax. Yellowjacket nests can be aerial, e.g. hanging from trees or attached to buildings; hidden in cavities, such as wall voids in buildings; or subterranean e.g. constructed in old rodent burrows. In cases where the nest is hidden or subterranean, a person can see the yellowjackets flying in and out of an opening but cannot see the nest.

Honey bees typically nest in artificially constructed hives. It is possible for them to nest in cavities in homes but this is not very common. While honey bees don't nest in the ground, bumble bees do. Bumble bees are stout, robust insects, usually black and yellow, and hairy. Both yellowjackets and bumble bees have annual nests, i.e. they last one year; they die when freezing temperatures arrive in the fall. However, honey bees have perennial nests which survive the winter and can live for multiple years.



Dan Martens, Univ of MN Extension

Photo 3: While people wonder if nests like this are bee hives, the papery material it is constructed from tells us this belongs to yellowjackets

It is very important to distinguish between yellowjackets and bees. If people believe they have honey bees, they may take steps to try to protect the nest or even try to have it moved despite the potential risk of stings. While it is true beekeepers can remove and relocate honey bees from a nest (if you have a confirmed honey bee nest around a home, contact the Minnesota Hobby Beekeepers Association), they do not want to and will not get involved with a yellowjacket problem. While yellowjackets are beneficial because they are important predators, they do minimal pollinating and do not need to be saved.

If you have a yellowjacket nest on your property, there are several options for dealing with it. If the nest is located a reasonably safe distance from where people may be present and the risk of stings is minimal, then just ignore it. Eventually, all of the insects in the nest die after hard frosts occur.

If a yellowjacket nest is present and you want to control it, keep a few things in mind. First, treat the nest during late evening or early morning when the yellowjackets are least active; this will help minimize the chance of stings. If after a day there is still activity, i.e. yellowjackets are still flying in and out, then repeat the treatment. If you are uncomfortable treating a yellowjacket nest, it is always an option to hire a pest management professional to deal with it; they have the experience and the appropriate tools to expertly eliminate nests.



Jeff Hahn, Univ of MN Extension

Photo 4: Yellowjacket commonly nest in the ground too!

When yellowjackets are nesting in the ground, the most effective means of controlling them is with a dust labeled for ground dwelling insects; the workers get the dust on their bodies and carry into the nest spreading it to the rest of the colony. Pouring a liquid insecticide into the nest entrance is less likely to be effective as the liquid may not reach the nest depending on where it is located within the burrow



Jeff Hahn, Univ of MN Extension

Photo 5: Hidden yellowjacket nests are tricky to control for residents; they should hire a pest management professional to do this type of job.

If you can see the nest, e.g. it is attached to the eaves, use a wasp and hornet aerosol spray and treat directly into the nest. However, yellowjacket nests that are found inside homes in wall voids, attics, concrete blocks, or similar spaces are much more challenging to control. An aerosol insecticide is not very effective. In fact, an aerosol spray can sometimes cause the yellowjackets to look for another way out, which often leads them to the inside of homes. Also, don't seal the nest opening until you know all of the yellowjackets are dead as this can cause the same reaction. It is usually best for a pest management professional to control hidden nests in buildings.

Ultimately, yellowjackets do not survive the winter. If a nest can be ignored until freezing temperatures arrive, all of the workers and the queen will die. The only survivors are the newly mated queens which have already left the nest. They will seek out sheltered sites in which to overwinter. Next spring, they will start their own nests in different sites (old nests are not reused).

Tuesday, September 16, 2014

September 15th Yard and Garden News

In this issue:

WCCO Radio "Smart Gardens" Q&A - September 6, 2014

Just Wait Out Foreign Grain Beetles

WCCO Radio "Smart Gardens" Q&A - September 13, 2014

Butterflies in slow motion flight

Butterflies in slow motion flight

Karl Foord, Extension Educator - Horticulture

I recently took a class on bee identification at the Southwest Research Station of the Museum of Natural History in the Chiricahua Mountains three hours west of Tucson, Arizona.
While traveling to one of the bee collection sites we passed a large puddle along the road. Two days previously a heavy downpour had soaked the countryside and this puddle downstream from an open cattle range provided the butterflies with water, sodium, and perhaps other needed nutrients.

I have always wondered about the flight of butterflies. Their flight often seems quite erratic. I understand this to be part of a strategy to avoid predators. Is their flight actually as erratic as it appears to us?

I returned to the puddle the following day and was happy to see that it was not completely dry. I was able to slow down their flight with a high speed camera capturing 3500 frames per second. If 30 frames per second is what we consider to be normal then this slows down the flight by a factor of 117.

What was seemingly erratic now seems quite graceful. Wouldn't you agree?

Notice how the wings curl to provide lift on both the forward and backward strokes of the wings. Also notice how the butterflies wing strokes are not constant and that they often drift before beginning a new stroke. Access the video at Butterflies in slow motion flight

Please enjoy the ballet.

Monday, September 15, 2014

WCCO Radio "Smart Gardens" Q&A - September 13, 2014

Thanks for listening!

We aren't always able to answer everyone's texted questions on the air, so we try to post a few along with answers here in the Yard & Garden News blog. Remember that you can always visit the U of M Extension Garden website for loads of gardening resources.

Hope you join us and our host Denny Long every Saturday, 8-9am, on WCCO Smart Gardens and happy gardening!

Question: Paver stone patio on north side of house has mold / moss in between stones. How do I get rid of this?

Answer: You can use a sharp tool to scrape / dig out moss and fill in spaces with builders' sand. You can plant low-growing, creeping plants like creeping thyme or wooly time in the spaces.
Mold can be removed with a bleach / water solution and a wire brush. Be careful not to get bleach on the plants nearby, your clothing or patio furniture.
   
Question: I just planted a 2" Autumn Blaze maple. What are you recommendations for watering?

Answer: Here is an excerpt from the U of M Extension publication Planting and Transplanting Trees and Shrubs (Gillman et. al):
Newly planted plants require routine watering. Typically, 5-7 gallons, applied to the root ball once a week, is an appropriate quantity of water to add to a newly planted tree or shrub; however, differing soil and weather conditions will affect the frequency with which water must be added. Examine the soil moisture 4-8 inches deep to determine the need for water. If the soil feels dry or just slightly damp, watering is needed. Soil type and drainage must also be considered. Well-drained, sandy soil will need more water, and more often than a clay soil that may hold too much water. A slow trickle of the garden hose at the base of the plant for several hours or until the soil is thoroughly soaked is the best method. Short, frequent watering should be avoided as this does not promote deep root growth but rather, the development of a shallow root system that is vulnerable to several environmental stresses.

Be sure to consult this publication for additional information about planting trees.

Question from Anne in Apple Valley: On my 'William Baffin' roses, the leaves turned yellow with brown spots, then dropped. Bare canes are still green. Is this fungal and should I treat before winter? Should I prune the canes back to the a foot from the ground and clean up to try and avoid re infection next spring? These are large 7- yr old plants and don't want to lose them.

Answer: It sounds as though your rose has black spot. Here is a good publication Rose Diseases (Pfleger et. al). Black spot on rose is a fungal disease caused by splashing water onto leaves. We had a rainy spring and summer and thus this was a "good" year for such diseases. Note that sanitation is a good place to start in reducing the occurrence next year. Treatment occurs during the growing season when the first signs of the disease occur. It is not appropriate to treat now. Diseased canes should be cut back a few inches into healthy wood. You can also help reduce water droplets that can foster fungal spores by watering at the base of the plant and mulching the roots. Space out the canes as you tie them to your trellis / fence so air can circulate, drying off leaves and canes.

Question: Should a Fat Albert spruce be fertilized now?

Answer: Stop fertilizing trees and shrubs in mid-summer. Fertilizing now will cause new growth to occur that can be damaged by cold temperatures. Water evergreens now up until you cannot water any longer. This will reduce the chance of desiccation and browning of needles. More on evergreens

Question: Can I prune the water shoots off my crab apple now? How often can we prune to preserve size and shape?

Answer: Crab apple trees should be pruned once a year in late winter while still dormant. This will reduce infestations by pests and all the plant to heal the cut wound more quickly when it begins actively growing in early spring. Remove water shoots and selectively prune branches to open up the canopy, allowing air and light to reach the inner branches and buds. Protect the tree from animal damage in the winter by surrounding the trunk with hardware cloth fencing or corrugated plastic tubing. More on pruning trees.

Question: How do I know when to re-pot a ZZ plant?

Answer: Zamioculcas zamiifolia or "ZZ plant" is not one of the plants I know well, I admit. After some reading, I found out it is a rainforest plant, but has about 3-4 months of dry conditions. The plant apparently does not do well when pot-bound / crowded; hence, it may stop developing new leaves and stems. That may be the indicator that it's time to re-pot. It is apparently an excellent houseplant that grows well indoors and has few if any pest issues. It may drop its leaves once a year and appear dead, but that is apparently just its dormant behavior. Soil should be well-drained. It does not need much fertilizer - either a slow release balanced fertilizer every three months or a very dilute liquid fertilizer (1/4 strength) when you water.

Friday, September 12, 2014

Just Wait Out Foreign Grain Beetles

Jeffrey Hahn, Extension Educator



Jeff Hahn, Univ. of MN Extension

Photo 1: Don't confuse tiny foreign grain beetles for flies or fleas

Very small, brownish beetles are being found in some buildings, especially homes that have been recently constructed. Proper identification is critical as these beetles may be confused for other insects, such as fruit flies, drain flies, or fleas. A foreign grain beetle is about 1/12th inch long and reddish brown with a flattened body.

Foreign grain beetles can also fly which is why they might be confused for small-sized flies. However, foreign grain beetles have a generally harder body compared to the softer bodied flies. Fleas also have a relatively hard body but are fattened instead from to side to side; fleas are also wingless and can't fly.

The favorite food of foreign grain beetles is fungi and so they are typically found in relatively damp areas. They are often associated with new construction because the moisture in wall voids when construction is first completed in conducive for fungi which then provides a food source for the foreign grain beetles. Despite their name, foreign grain beetles are not typically found infesting food products in homes. They prefer to attack old, moldy grain products.

Fortunately foreign grain beetles are only a temporary nuisance. Adult beetles are active during late summer and early fall and then go away on their own. The beetles will survive only for one or two years in a home before it becomes too dry to support fungi and the beetles. Tolerate foreign grain beetles until they go away on their own. The best control is physical removal, e.g. with a vacuum. Insecticides do not prevent foreign grain beetles from appearing and their use is not recommended.

Click here for more information on foreign grain beetles.

Monday, September 8, 2014

WCCO Radio "Smart Gardens" Q&A - September 6, 2014

Thanks for listening!

We aren't always able to answer everyone's texted questions on the air, so we try to post a few along with answers here in the Yard & Garden News blog. Remember that you can always visit the U of M Extension Garden website for loads of gardening resources.

Hope you join us and our host Denny Long every Saturday, 8-9am, on WCCO Smart Gardens and happy gardening!

20140714_123750.jpgQuestion: It looks like my Black-Eyed Susans have powdery mildew. Will they be OK next year and what can I do?

Answer: Powdery mildew is a common fungus in Minnesota landscapes that results in a white powdery covering over leaves. Usually damage is cosmetic and the plant recovers fine the next year. The best means of managing this pest is to (1) select resistant plants, (2) space plants properly to ensure air circulation, (3) water at the base of the plant (vs. overhead watering) to minimize splashing spores onto leaves, and (4) clear away infected plant material. Fungicides are available, but usually not necessary and especially near the end of the growing season when plants are starting to dieback for the winter. More about powdery mildew.

Question: My bee balm is done blooming. When can I cut back the dead blooms?

Answer: You should deadhead (cut off) spent blooms on perennials like bee balm (Monarda) throughout the growing season. This improves the look of the plant, reduces the plant energy going into producing seed, and also can prompt a second, though typically smaller, re-bloom. About pruning perennials.

Question: When should you prune spireas?

Answer: When you prune a flowering shrub depends on whether the plant blooms in the spring (on old wood) or in summer (on new wood). If the plant blooms in the spring, it grows or "sets" flower buds for the next year within a few weeks of blooming, so it should be pruned within two weeks of flowering. If the plant blooms in the summer, flower buds are produced on the new spring growth, and it should be pruned in late fall or early spring before growth begins. More about pruning shrubs.

Question: I have a row of crabapples I have diagnosed as having apple scab. Is this something I can treat myself or do I need a professional?

Answer: Like all gardening problems, a correct diagnosis is critical before deciding on any mode of action. Apple scab can be managed by a home gardener with fungicides. More about managing apple scab.

P1250030.JPGLooking forward, Minnesota gardeners can reduce pests (diseases, weeds and detrimental insects) by choosing resistant plant cultivars and varieties that are suitable to the conditions of your site (light, soil, hardiness zone, etc.). It's also critical to a healthy landscape to space plants according to their mature size to ensure better air circulation and light to reach the plants, and the plants to achieve their natural form. Mulch plants and water at the base pf the plant to avoid splashing soil-borne pathogens (fungi, bacterial, etc.) onto lower leaves. Properly pruning plants and cleaning up dead leaves and other plant debris from your garden will also help reduce pests that overwinter in these materials.

Question: Is it OK to fertilize evergreens in September and October?

Answer: Time to stop fertilizing plants as fertilizing will prompt new growth. Our plants start to move into dormancy as the weather changes, and any new growth can be killed by cold weather. That said, be sure to keep watering your evergreens - and other woody plants - throughout the fall to help reduce the possibility of desiccation during the cold dry winter months. More about protecting trees from winter damage.

Question: We have some "critters" tunneling in our raised vegetable / flower beds and actually killing plants. What should we do?

Answer: Gardening with wildlife is always a challenge! Identify the animals first and try to determine how they entering your raised beds. You don't mention how your raised beds are constructed, so I am going to assume they are built in wood frames about 6-12 inches deep. Are the animals climbing into the beds? If so, hardware cloth fencing (very small wire grid) dug won below the surface and high enough to keep them out should help. Are they tunneling in through a hole or crack in your raised bed structure? If so, patch / plug the hole or crack. If they are entering from tunnels underground and if it's logistically possible, remove the soil, line the bed with hardware cloth, and put the soil back into the raised bed.

Repellents are also available, but often need to be reapplied and may not be available for the kinds of edibles you are growing.

Question: We recently lost two large birch trees in our landscaping near our house. We just had the stumps ground out. Can I replant another tree in that same spot?

Answer: Since you ground out the stump, then yes, you can replant. That said, before planting, try to figure out why the trees died - too close to the foundation, pest problems, poor soil, unsuitable conditions for the tree species - and try to correct the problem(s) before planting again. Paper birch do not do well in our urban conditions - compacted soil, heat, dry conditions, alkaline soil. Understand your soil and choose a new tree that will thrive in your soil, the amount of light and the space available (note the mature width of the canopy when you are looking at tree species). Then plant the tree correctly, provide adequate water and staking. More about planting trees.

Question: We are going to be over seeding our lawn due to bad winter damage. We live in sandy acidic soil. We have removed most of the moss. Can we seed and then lime?

Answer: Turfgrass species grow best in slightly acidic soil.  I would suggest having the soil tested to see what the pH is.  If the pH is below 6, then lime would be recommended to increase this slightly.  Turfgrasses grow best at a pH of 6.5.  You can lime anytime, either before or after seeding.  Basic soil tests are $17.00 from the University of Minnesota soil testing laboratory. If the pH is in fact low, there will be a recommendation on the soil test for how much lime to apply.  

Question: How do I get rid of creeping charlie?  

Answer: Creeping charlie can be an aggressive weed in many sites and has a particular competitive advantage over turfgrass in wet/shaded environments.  Herbicides used to control creeping charlie provide marginal success due to the waxy leaf surface that repels herbicide applications.  I suggest making an assessment of how much existing grass is in the lawn that you are trying to preserve.  If the lawn is 75% grasses, then I would suggest several applications of a selective broadleaf herbicide, which will control the creeping charlie and preserve the grass species.  The best herbicides for this include post emergent combination herbicides with the active ingredient triclopyr. Sometimes these herbicides are labeled as clover or oxalis killers.  Fall is the best time to apply these herbicides, and multiple applications spaced 2-3 weeks apart would generally be required for any success.  The the lawn is predominately creeping charlie, the best option would be to control it with a complete vegetation killer like Roundup (glyphosate) or diquat.  till several applications will be required.  Following successful control of the existing vegetation, seed shade tolerant turfgrass species such as the fine fescues or tall fescues.  If significant wet shade is present, rough bluegrass (Poa trivialis) is a species that might give you better results. More information on creeping charlie control.

Where to purchase grass seed.

Question: My back yard has always had a lot of moss. I've tried raking it out and seeding with grass seed but can't seem to get rid of the moss. Is there a way to get rid of the moss?

Answer: Moss is generally an indication of a poor environment for growing turfgrass, which includes shaded, moist, and compacted sites.  General recommendations for controlling moss in lawn situations would include reducing the amount of shade (pruning), aerating to help with water infiltration, reducing irrigation frequency, increasing the mowing height, and planting shade tolerant grass species.  Moss takes over and establishes in lawns with poor stands of turf, but rarely competes with the turf itself.  I suggest aerating to reduce compaction and pruning to improve light penetration and air movement.  Follow this by seeding with shade tolerant grasses: moist to dry shade- fine fescues or tall fescue, wet shade- rough bluegrass.  Moss controls on the marketplace will only have marginal success.  Start with the cultural control options to improve the health of your grass, followed by seeding.
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