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Showing posts from 2010

What Is Biting Me?

Jeffrey Hahn, Asst. Extension Entomologist

Photo 1: Bed bugs. Jeff Hahn.A common call that has been received recently has been from people that have been experiencing bites of an unknown source. It is challenging to correctly diagnose these problems. It is important to know that unknown bites can be the result of insects as well as non-insect causes. If it is an insect infestation, the most common causes are bed bugs and fleas.
Bed bugs have been on the increase over the last 10 or so years. Adult bed bugs are about 1/4 inch long, brown, and similar in size and shape to wood ticks; newly hatched bed bug nymphs are about 1/16th inch long or about the size of a pinhead. Bed bugs like to hide during the day and generally prefer to bite at night so it's possible to be bitten and not realize it. When looking for bed bugs, first check out bed rooms and other places where people sleep or rest. Other good areas to look are places where luggage is stored.
Bed bugs like to hide in cracks and …

Does climate affect the taste of apples? - Minnesota vs. Washington grown Honeycrisp Apples

Thaddeus McCamant

In November, the stores were running low on Minnesota Honeycrisp and started replenishing the shelves with Honeycrisp shipped from Washington. For a while, my local grocery store had Minnesota and Washington Honeycrisp in the same bin. At the time, a friend complained to me about some apples he had recently bought. "I don't even think they are Honeycrisp," he told me, "the store must be selling red Delicious."

Even before he brought me an apple, I told him that they were Honeycrisp, but they were raised in a low elevation area of Washington.

I always get a little defensive when people use Delicious as the ultimate example of a bad tasting apple. Some of the best apples I have ever eaten were Washington Delicious. Twenty years, ago, I worked with about thirty apple orchards along the Washington-Oregon border. Some orchards were planted in the true desert near the Columbia River, while others were high in the foothills of nearby mountains. W…

Hosta Virus X: New Information

Grace Anderson, MAg, UM Department of Plant Pathology
Hennepin County Master Gardener

Photo 1: Hosta 'Sum and Substance' infected with Hosta Virus X. Note the crinkled tissue between the leaf veins. Grace Anderson.HVX is a plant virus in the Potexvirus group first identified in 1996 by Dr. Ben Lockhart: Plant Virologist, Department of Plant Pathology, University of Minnesota. It is thought to be host specific and is not transmitted by traditional insect fungi or nematode vectors, or via seed or pollen. It is transmitted mechanically through wounds created during propagation or transplanting, or any time sap to sap contact is made through dividing or trimming plants. Vegetative propagation of infected plants, whether by tissue culture or division, will produce infected plants. Once a plant has HVX, there is no cure and it must be destroyed.

HVX reduces plant vigor and destroys foliage appearance through leaf distortion, color bleeding, and necrosis. Symptoms vary among cultiv…

What are your woody plants doing right now?

Karl Foord, UMN Extension Educator

Well, here we are in Minnesota where most parts of the state are sitting under several feet of snow. This led me to think about what was the state of my apple and maple trees.
The plants in our state are adapted to northern climates with harsh winters that are unfavorable to plant growth. One mechanism that these plants have adopted to survive involves a suspension of growth termed dormancy.

The bud that overwinters in an apple tree is a miniature shoot with apical meristem, leaf and perhaps flower primordial, and axillary buds enclosed by modified leaves termed bud scales. Bud scales protect the bud from mechanical injury, restrict gas exchange and prevent desiccation.

Preparation for winter and true dormancy
The buds are the photoperiod receptors and in preparation for winter undergo a series of physical and physiological changes triggered primarily by the shorter days of late summer. These short days (actually long nights) trigger the production of…

Calendar: January 1, 2011

Happy new year from the Yard and Garden News team!

Start the new gardening year by familiarizing yourself with the University of Minnesota Extension's source of reliable, localized information on the web. Visit Garden Info to learn about growing plants indoors, in flower or vegetable gardens, and in landscapes.

Keep holiday poinsettias in tip-top condition for months by placing them near a sunny window and rotating the pots a quarter-turn every few weeks. water the soil thoroughly whenever its surface feels slightly dry; don't wait until the leaves begin to wilt. Fertilize monthly at first, then every two or three weeks as the days grow longer in March. Always mix your fertilizer half strength to avoid problems.

Bring pots of amaryllis up from the basement to force them into bloom. Water them thoroughly, then put them in a sunny window. They usually bloom in six to eight weeks, depending on how warm you keep your home. Often, flower stems appear first, but don't be alarmed i…

What Can I do About Bed Bugs?

Jeffrey Hahn, Asst. UMN Extension Entomologist

Bed bugs are often a very challenging and costly problem with which to deal. The best long-term control is to hire an experienced professional pest control company to treat your home. They have the expertise, experience and effective products to properly control bed bugs. These insects are too difficult for a homeowner to eliminate themselves. However, while you cannot eradicate bed bugs are your own, there are some steps you can take to help reduce their numbers.

Make Sure You Have Bed Bugs

Not every insect you see is necessarily a bed bug. Especially with all of the media attention recently, it is easy to think that you see bed bugs in every crack and crevice in your home so be sure you know what they look like. Despite what some people believe, bed bugs are not microscopic. Adults are similar in size and shape to a wood tick. They measure about ¼ - 3/8 inches long and are oval, flattened, brown, and wingless.. Young bed bugs ar…

What's Happening at the Plant Disease Clinic

Karl Foord, UMN Extension Educator
Dimitre Mollov - Director of Diagnostic Services, UMN Plant Disease Clinic


Dimitre Mollov at his dissecting scope. Karl Foord. Every year brings its unique weather but 2010, with its unseasonably warm April and our cool and wet late May and June, presented some ideal conditions for disease. To explore this further I visited with Dimitre Mollov, the Director of Diagnostic Services of the Plant Disease Clinic of the University of Minnesota. Dimitre took over leadership of the lab some three years ago and to date has analyzed some 6,500 samples from 22 states. These samples have included some 1000 pathogens on some 300 hosts. Eighty plus percent of the samples come from commercial entities where control decisions have greater financial impact, but there may be times when it might be worth it for a homeowner to send a sample to the clinic. How are samples processed and how are the results analyzed at the clinic?

The challenge in diagnosis


You can see…

The Uncertain Future of the Butternut Tree

Michelle Grabowski, UMN Extension Educator


Photo 1: Nuts from a butternut tree B.Cook Michigan State University, Bugwood.org.Once commonly planted near farmstead houses for the nuts it produces, many Minnesotans would not recognize a butternut tree today. Butternut (Juglans cinerea), also known as white walnut, is a native tree in Minnesota and a close relative of black walnut (Juglans nigra). This nut bearing tree provides food for squirrels and other rodents and is used for wood carving and furniture building. Butternut is hardy to zone 3 and is therefore a valuable tree in northern Minnesota, where black walnut will not grow.



Although butternut is naturally found in small numbers in native forests of the United States, these populations have decreased due to a lethal disease known as butternut canker. Butternut canker is caused by the fungus Sirococcus clavigignenti-juglandacearum and is responsible for the near extinction of butternut in some eastern forests. Populations of butternu…

Calendar and Contributors: December 1, 2010

Make cleaning your houseplant foliage part of sprucing up your home for the holidays. Clean leaves look best-- and they capture more light for photosynthesis. Wash both the surface and underside of each leaf with lukewarm water that's had a drop or two of dishwashing liquid added. For more information, see the wide range of houseplant care publications on the University of Minnesota Extension Garden Info site.

Poinsettia's are among the easiest holiday plants to grow. But first you must choose a plant and get it home without suffering cold damage. It must be wrapped well, then transported in a heated vehicle. Cut the bottom of the pot so excess water will drain out, and place the poinsettia in a bright- even sunny- location. water thoroughly when the soil surface begins to dry, and fertilize monthly after four to six weeks.

Want to see more poinsettias? Spend some time at the Marjorie McNeely Conservatory in St. Paul's Como Park. The annual holiday display will help you fo…

The Plight of Bees

Marla Spivak (University of Minnesota); Eric Mader and Mace Vaughan (Xerces Society for Invertebrate Conservation); Ned Euliss (USGS).
Excerpted from feature article to appear in upcoming issue of Environmental Science and Technology.

Bee Declines

Colony collapse disorder (CCD), the name for the syndrome causing honey bees to suddenly and mysteriously disappear from their hives--thousands of individual worker bees literally flying off to die--captured public consciousness when it was first named in 2007. Since then, the story of vanishing honey bees has become ubiquitous in popular consciousness--driving everything from ice cream marketing campaigns to plots for The Simpsons. The untold story is that these hive losses are simply a capstone to more than a half-century of more prosaic day-to-day losses that beekeepers already faced from parasites, diseases, poor nutrition, and pesticide poisoning.

The larger story still is that while honey bees are charismatic and important to agricultur…

Help Your Woody Ornamentals Survive the Coming Winter

Kathy Zuzek, UMN Extension Educator

Photo 1: Winter burn symptoms. Kathy Zuzek, UMN Extension.The effects of winter sun, wind, temperature fluctuations, snow, and ice can all combine to make winter a high-hazard time for tree and shrub health. Animal browsing is an additional challenge in our winter landscapes. Here's a checklist for gardeners who want to minimize injury to woody ornamentals in the coming winter.

Apply tree wraps and tree guards to prevent sunscald. Sunscald occurs when winter sun heats up bark on the south or west side of a tree enough to stimulate cambial activity. When shading or sunset causes the air temperature to drop quickly, the activated cambium is killed resulting in dead bark on the south or west side of a tree in the form of sunken, dried, or cracked areas. To prevent sunscald, tree wraps and guards should be applied in fall. They should be light-colored to reflect sun and to keep bark at a lower temperature on sunny winter days. Pay special atte…

Pollinator Blues: Part II

Karl Foord, UMN Extension Educator

Pollinator Blues - Part II

To approach the problem of creating a bee friendly garden,I first researched the plants that are pollinator friendly and created a table of pollinator friendly plants from the Xerces site (Exhibit 1).

Second, I used the following recommendations from the Urban Bee Garden site as criteria for selecting plants; the goal being to insure that continual bee floral food will be available for the complete growing season.

1. Plant a minimum of three plant species that bloom at any given time during the growing season i.e. spring, summer and fall.

2. Each species of flower should be planted to a minimum patch size of approximately 5 ft. x 5 ft. Patch size is important because smaller patch sizes will often be ignored, even if the plant is quite attractive to the bees.

3. Higher bee diversity and abundance occurs when gardens have a rich assortment of bee plants. It also appears that bees remain longer in a garden…

Beware of Bed Bug Internet Hoax

Jeffrey Hahn, Asst. Extension Entomologist

There is a story making the rounds on the internet these days. It goes like this:

Hi All: A bit of information that you might like to know about. We have friends here in our community and one of their sons is an entomologist (insect expert), and has been telling them that there is an epidemic of bed bugs now occurring in America. Recently I have heard on the news that several stores in NYC have had to close due to bed bug problems, as well as a complete mall in New Jersey.

He says that since much of our clothing, sheets, towels, etc. now comes from companies outside of America, (sad but true), even the most expensive stores sell foreign clothing from China, Indonesia, etc. The bed bugs are coming in on the clothing as these countries do not consider them a problem. He recommends that if you buy any new clothing, even underwear and socks, sheets, towels, etc. that you bring them into the house and put them in your clothes dryer for at least…

Rust Diseases of Lawn Grasses Very Common this Fall

Bob Mugaas, UMN Extension Educator


Photo 1: Areas of rust infection on Kentucky bluegrass lawn. Bob Mugaas. Rust diseases of our lawn grasses have been on the increase throughout much of this fall period but became especially evident during the drier conditions of October. Rust infestations usually show up as areas of yellow to orange-yellow grass blades, see Picture 1.


Upon closer examination of the grass blade, one will usually see orange colored, tiny tuft-like pustules breaking through the grass leaf surface, see Picture 2. It is these pustules that produce massive numbers of individual spores. These are the same spores that can become air-borne and cover our shoes or lawn mowers in an orange 'powder' as we walk through rust infected areas of the lawn. They can also re-infect other grass plants that in turn can produce more of the same spore producing rust pustules thus carrying on the infection cycle.

What is a rust disease?


Rust diseases have very complex life cycles…

Prevent Snow Mold on Lawns Now

Michelle Grabowski, UMN Extension Educator


Photo 1: Snow mold damage on a lawn in spring 2010 Photo by T. Burnes. In the spring of 2010 snow melted away from yards and landscapes to reveal round dinner plate sized patches of tan or gray matted turf. Two fungi, known as snow molds, were responsible for the damage. Many gardeners were dismayed to learn that little could be done in the spring to cure snow mold. Rather they had to wait for the weather to change and the grass to recover. This is because the time to prevent snow mold is not in the spring. The time is now.


Snow mold is caused by two different fungi, Microdochium nivale and Typhula sp. Both of these fungi thrive at temperatures just above or below freezing with high levels of moisture. Although snow cover is not a requirement for the growth for snow mold, snow cover provides ideal conditions for the fungi. Of course, gardeners cannot control how much snow Minnesota will receive this winter or how long that snow will stay. Gar…

Calendar and Contributors: November 1, 2010

Garden Calendar

Check out more fall tips to reduce snow mold next spring from UMN Extension Educator Bob Mugaas, as featured with Bobby and Belinda on Kare11.

Be a responsible gardener and remove any buckthorn shrubs still growing on your property. They're easy to spot late in autumn when most other shrubs have lost their leaves. Buckthorn has green leaves and small clusters of black berries, with sharp barbs sparsely placed. Unfortunately, they're difficult to dig out. Larger plants will require brush killer next spring or summer. Do you have buckthorn in your yard? Learn more about buckthorn from the Minnesota DNR.

Buckthorn (R. Frangula) and all cultivars are considered to be restricted noxious weeds, according to the DNR. Check this list of Minnesota and Federal Prohibited and Noxious Plants by Scientific Name if you are ever uncertain about something in your yard.


Contributors

The Yard and Garden News will now feature brief profiles of the contributors! We've asked UMN…

Bringing tropical plants into the house for the winter, or a short biochemistry lesson

Karl Foord, UMN Extension Educator


Jeff Hahn. Each fall brings the challenge of not only what tropical plants to keep over the winter, but also how to keep them healthy in the Minnesota winter home environment. Invariably despite all efforts I will provide winter refuge for aphids and mites. It seems like this is the perfect time to use imidacloprid. As a systemic it will control the aphids and has no chance of impacting natural populations of insect predators or pollinators in this environment. However, Imidacloprid will not control spider mites. Why not?


The fact that an effective insecticide will usually not harm a mite seems counter intuitive. After all they are both Arthropods i.e. small creatures with exoskeletons and jointed appendages. Although following this basic pattern, the body structure differences between mites and insects are dramatic. On closer inspection the mite has no antennae, no wings, 4 pairs of legs, an unsegmented abdomen, and simple eyes. Whereas an in…