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Watch out for Yellowjackets!

Jeffrey Hahn, Extension Entomologist




Jeff Hahn
Photo 1: Yellowjacket leaving the entrance of an aerial nest. Note black and yellow coloration

This is the time of year when yellowjacket nests are reaching their maximum size and become conspicuous to residents. Two sites where yellowjackets are most problematic are nests that are in the ground and those that are in hidden voids in buildings. A lot of people have mistakenly identified yellowjackets as bees (perhaps because of all of the recent discussion of bees in the media) and are looking for information on how a yellowjacket nest can be moved and saved. Yellowjackets are not important pollinators and it is not necessary to take extraordinary measures to save them. There are not any services that will remove a yellowjacket nest and relocate it.


Jeff Hahn
Photo 2: Honey bee. Note the brown and black body. Don't confuse honey bees with yellowjackets!


Yellowjackets are about ½ inch long, black and yellow, and with few hairs …

Cicadas are common now

Jeffrey Hahn, Extension Entomologist



Dan Mullen
Photo 1: Dog day cicada, also called annual cicada.

Many people are noticing cicadas now. Despite their appearance, they are harmless to people and property. An adult cicada is a large, one inch long, stout insect with a green or brown body with black markings. Cicadas have four fly-like wings; the first pair is much longer than their abdomen which they hold tent-like over their bodies. They also have very short antennae.

There are two basic types of cicadas, dog day (also called annual) and periodical cicadas. Dog day cicadas, Tibicen spp., do not have a synchronized life cycle so there are some that emerge every year in Minnesota. Periodical cicadas which do not occur in Minnesota spend 13 or 17 years as a nymph in the ground and then emerge together in tremendously large numbers.

While cicadas are present here from July into September, they are more often heard than seen. They produce a high-pitched sound during the day tha…

August 15 2013 Issue of Yard and Garden News

Dutch elm disease: a historical disease that threatens Minnesota's elms today

M. Grabowski, UMN Extension
Photo 1: Elm tree killed by Dutch elm disease

Michelle Grabowski, UMN Extension Educator


Dutch elm disease (DED) is a fungal disease that results in yellowing, wilting and browning of leaves, death of branches and eventually death of the entire tree. Today, the disease can be found in every county in Minnesota yet it is estimated that 1 million elms still remain within communities. Several management strategies have been developed that allow elms to survive if properly cared for. Elm trees can be protected from DED through fungicide injections, infections can be removed and treated if caught early, and new cultivars of elm offer resistance or tolerance to DED. To learn more on how to identify and manage the disease read the new UMN Extension publication on Dutch elm disease.

Aster Yellows in 2013

Michelle Grabowski, UMN Extension


M.Grabowski, UMN Extension
Photo 1: Purple cone flowers infected with aster yellows

Many gardeners had never heard of the plant disease called aster yellows before 2012. As summer progressed, however, flowers on purple cone flowers open up to green spikey alien like blossoms, carrots were thin, hairy and bitter when dug up and plants from onions through tomatoes turned a sickly shade of yellow. The plant disease aster yellows was responsible for all of this.

Aster yellows is caused by a phytoplasma, a small bacteria that lives only within the vascular system of a plant or within the aster leafhopper that carries it from plant to plant. Once a plant is infected, the aster yellows phytoplasma moves systemically through the plant, infecting every part from the roots through the flowers. Symptoms of the disease include yellowing of leaves and stems, unusual flower formation and clusters of weak stems known as witches brooms. The aster yellows phytoplasma…

Flower Video Library Returns for 2013 - Shade Plants II

Karl Foord - Extension Educator, Horticulture


Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture







Karl Foord
Photo 1: Garden Glow Dogwood (Cornus hessei 'Garden Glow')

Garden Glow Dogwood



Karl Foord
Photo 2: Bracken Fern (Pteridium aquilinum)

Bracken Fern



Karl Foord
Photo 3: Lady's Mantle (Alchemilla mollis)

Lady's Mantle



Karl Foord
Photo 4: Hosta 'Glory'

Hosta 'Glory'



Karl Foord
Photo 5: Bugbane, Black Snakeroot (Actaea racemosa)

Bugbane



Karl Foord
Photo 6: Purple Fringed Loosestrife Lysimachia ciliata

Purple Fringed Loosestrife

Editors note: These videos were filmed in 2012

Flower Video Library Returns for 2013 - Sun Plants II

Karl Foord - Extension Educator, Horticulture


Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture





Karl Foord
Photo 1: Russian Sage (Perovskia atriplicifolia)

Russian Sage



Karl Foord
Photo 2: Ingwersen's Variety Geranium (Geranium macrorrhizum 'Ingwersen's Variety')

Ingwersen's Variety Geranium



Karl Foord
Photo 3: Adam's needle (Yucca filamentosa)

Adam's Needle (Yucca filamentosa)



Karl Foord
Photo 4: Giant Fleece Flower (Persicaria polymorpha)

Giant Fleece Flower



Karl Foord
Photo 5: Rosa 'Summer Waltz')

Rosa 'Summer Waltz'

Giant Onion Rose Mallow Combination



Karl Foord
Photo 6: Rose Mallow (Hibiscus 'Blue River II')

Harebell Campanula



Karl Foord
Photo 7: Harebell Campanula (Campanula rotundifolia)

Editors note: These videos were filmed in 2012

Redheaded Flea Beetles in the Landscape

Jeffrey Hahn, Extension Entomologist


Linda Treeful
Photo 1: Redheaded flea beetle on turtlehead (Chelone). Note the irregular brown patches of feeding damage on the leaves.

The redheaded flea beetle, Systena frontalis, is a native insect to Minnesota. It is small, about 1/8 to a ¼ inch long. It has a shiny black body with an orangish red head and moderate length antennae. Like other flea beetles, its hind legs are enlarged and made for jumping.

Redheaded flea beetles feed on a wide variety of plants, especially agricultural crops such as corn, soybeans, cabbage, and alfalfa as well as many weeds. They are now being found in the landscape and nurseries for seemingly the first time where they have been reported feeding on hydrangea, viburnum, and other shrubs as well as many perennials.

Adults typically hatch in July and August and are active on plants until September.

Their feeding can cause small holes which can create a skeletonized appearance in the leaves. In plants with th…

Genista Broom Moths Return to Minnesota

Jeffrey Hahn, Extension Entomologist



Pam Hartley
Photo 1: Genista broom moth caterpillars on false indigo.

Genista broom moths, Uresiphita reversalis, were found last year for apparently the first time in Minnesota. They fed almost exclusively on false indigo (Baptisia) here. Other plants that they are known to attack include lupines and honeysuckle (Lonicera spp.)

It was thought that their appearance here the result of migrant moths moving into Minnesota, probably with the help of storm fronts. The question was whether they would survive winters in Minnesota and would we see them again next year. It is not clear whether any of them survived our winter but it is clear that they are in Minnesota again in 2013 as reports have been coming in since mid-July. Most of the sightings have been in the Twin Cities area, but this caterpillar has also been spotted west of Minneapolis in McLeod County. Most of the sightings have been on false indigo with one report on lupine.

Interestingly, …

Observations from a Pollinator Garden - Wasps

Karl Foord - Extension Educator, Horticulture





Karl Foord
Photo 1: Flower garden for pollinators



Karl Foord
Photo 2: Great black wasp (Sphex pensylvanicus)



Karl Foord
Photo 3: Great black wasp (Sphex pensylvanicus) on left



Karl Foord
Photo 4: Great black wasp (Sphex pensylvanicus) and golden digger wasp (Sphex ichneumoneus) on Culver's Root (Veronicastrum virginicum)

I am not sure what I expected when I created this pollinator garden (photo 1), but I have certainly gotten a whole new perspective on what happens in a flower garden. I have encountered so many different species that I will create a series of pollinator garden observations. I will begin with wasps and follow up with many types of flies and bees.

The garden has been continually patrolled by a great black wasp (Sphex pensylvanicus). This wasp is perceived as a black streak that weaves its way around the different plants in the garden searching for prey (photos 2 & 3). It only rarely lands to fuel up on nectar at…

Grape pelidnota

Jeffrey Hahn, Extension Entomologist

Grape Pelidnota


Jeff Hahn
Photo 1: Grape pelidnota-- a big scarab beetle

A conspicuous insect has been showing up this summer around people's gardens and homes. A grape pelidnota, Pelidnota punctata, is a type of scarab beetle that looks like a big June beetle. Also known as grapevine beetle, it is a good sized insect measuring about one inch long. It is a rusty orange color with six black spots on its body (two on its thorax and four on its wing covers).

Grape pelidnotas can be found throughout the late spring and summer. Like their name suggests, the adults feed on grapes, although they typically do not cause much damage (just handpick them if they become numerous). The larvae are associated with rotting hardwood tree logs and stumps. The adults are attracted to lights so you can find one around your home even if you don't have grapes. Although they might look imposing, grape pelidnotas are harmless to people and pets. They are ju…

August 1 2013 Issue of Yard and Garden News

Flower Video Library Returns for 2013 - Shade Plants

Karl Foord - Extension Educator, Horticulture


Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture





Karl Foord
Photo 1: Gooseneck Loosestrife ( Lysimachia clethroides)

Gooseneck Loosestrife





Karl Foord
Photo 2: Variegated Japanese Knotweed (Fallopia japonica 'Variegata'.)

Variegated Japanese Knotweed





Karl Foord
Photo 3: Goatsbeard (Aruncus dioicus)

Goatsbeard





Karl Foord
Photo 4a: Jack-in-the-Pulpit (Arisaema triphyllum)



Karl Foord
Photo 4b: Jack-in-the-Pulpit (Arisaema triphyllum)

Jack-in-the-Pulpit





Karl Foord
Photo 5: Siberian Bugloss (Brunnera macrophylla)

Siberian Bugloss Brunnera



Dry Shade

Editors note: These videos were filmed in 2012

Flower Video Library Returns for 2013 - Sun Plants

Karl Foord - Extension Educator, Horticulture


Click on the link to see the video with host Dr. Mary Meyer, Professor of Horticulture





Karl Foord
Photo 1: Flowering Onion (Allium spp.)

Flowering Onion



Karl Foord
Photo 2: Our host Dr. Mary Meyer showing the William Baffin Rose

William Baffin Climbing Rose



Karl Foord
Photo 3: May Night Salvia (Salvia x sylvestris 'Mainacht'

May Night Salvia



Karl Foord
Photo 4: Gas Plant (Dictamnus albus)

Gas Plant



Karl Foord
Photo 5: Ozark Sundrops (Oenothera macrocarpa)

Ozark Sundrops Oenothera

Little Rocket Ligularia



Karl Foord
Photo 6: Little Rocket Ligularia (Ligularia stenocephala 'Little Rocket')

Lamb's Ear



Karl Foord
Photo 7: Lamb's Ear (Stachys byzantina)

Editors note: These videos were filmed in 2012