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Showing posts from July, 2018

A day in the life of an Extension educator: Unearthing a root flare

Using a Korean hand hoe to unearth the maple root flare. Note the stem circling root in the foreground  Sometimes being in Extension is a double-edged sword: you know enough to get yourself in deep. In my case, under the deck digging 12 inches below the soil surface for six hours.

Basil downy mildew is taking down MN basil

Sweet basil plant infected with basil downy mildew M. Grabowski, UMN Extension  Warm summer days are typically a great time for making pesto and caprese salad. This year many gardeners, disappointed by basil plants with yellowing leaves with dark blotches, are wondering what went wrong. The answer is a plant disease called basil downy mildew. First found in Minnesota in 2012, downy mildew is a devastating disease of basil, resulting in infection and complete loss of the plant. Basil downy mildew is caused by Peronospora belbahrii , a water mold that thrives in warm humid conditions. The pathogen cannot survive Minnesota’s harsh winter weather, but can be brought into the state on infected seeds, transplants, or as spores on warm moist air currents. Weather conditions have been ideal for basil downy mildew in Minnesota this summer. How do I know if my basil has downy mildew? Areas of the leaf between major veins turn yellow Dark brown to black blotches form on l

Do annual flowers attract pollinators? We want to know!

St. Paul campus Flowers for Pollinators site "Plant flowers for pollinators" is a key message from our UMN bee experts. But what about annual flowers? Are they attractive to insect pollinators? We are currently in Year #4 of our study, examining whether pollinators such as honey bees, flies, bumble bees and other native bees, beetles, etc. would come visit the blossoms on popular annual flowers. Annuals we're watching Some favorites from the 30 varieties currently under observation: Dakota gold sneezeweed (  Helenium ), Showstar butter daisy ( Melampodium ), annual Rudbeckia 'Orange fudge' and 'Prairie sun'; dwarf sunflowers ( Helianthus ) like 'Suntastic pink biocolor', and my personal favorite, 'Music box mix'. Cosmos  'Double click' was popular last year - will it be this year? Right now Salvia 'Purple fairy tale' has been full of honey bees on the St. Paul campus. Extension educator Julie Weisenhorn at

Springtails love moisture

A typical springtail.  Note the furcula, the appendage for jumping on the tip of the abdomen on the left. Photo:  Susan Ellis, Much of Minnesota has experienced consistent rains through the spring and summer this year. This has led to an increase in the numbers of springtails in and around homes and other buildings. Springtails love damp conditions and are typically found in soil, leaf litter, lichen, under bark, decaying plant matter, and other areas of high moisture. Given an opportunity, they will also inhabit your home. What do springtails look like? Springtails are very small, between 1/16th - 1/8th inch long. They are usually slender insects (there is a group of springtails that is round and stout that is sometimes found in gardens). Most springtails are dark-colored, brown, grey or black although some species are also white, and some are even iridescent and brightly colored These tiny insects are wingless and cannot fly but they can jump. They use a

Trees Not Looking Too Healthy?

Evergreens, Maples, Oaks and more struggling this summer Arborvitae killed by winter drying. Photo: DNR One of the big headlines for gardeners and home owners this year is all about trees. Trees appearing to turn brown, trees turning yellow or not leafing out at all; conifers with multiple dead limbs particularly among the lower branches, even dying outright. So what’s happening?  The DNR forest health team tracks what’s happening statewide and in each region so they can help address problems both for the trees in our forests and at home.  Here’s a summary of their Summer 2018 findings to date: Evergreens: Winter winds prove fatal In this summer’s “Forest Insect and Disease Newsletter,” the team said since May, it has fielded reports from Anoka, Fillmore, Freeborn, Goodhue, Hennepin, Houston, Rice and Winona counties about dead evergreens—in particular black hills spruce, white cedar (arborvitae) and white pine. DNR Forest Health Specialist Brian

Produce and floods: A bad combination!

Flooded vegetable garden near Northfield. June, 2014. Photo: Anne Sawyer Portions of Minnesota have been inundated with rainfall and flooding in recent weeks. Unfortunately, floodwaters can be contaminated with all kinds of things, including raw sewage from septic systems or municipalities, manure from farms or fields, and chemicals or other contaminants.  Why are floods bad for produce? When it comes to produce, it’s essential that gardeners understand that floodwaters can contain harmful microbes such as E. coli or salmonella that could contaminate produce. If any edible portions of produce were touched by floodwater, that produce may be contaminated and should not be considered safe to eat.  Once bacteria or other pathogens contact produce, they can be nearly impossible to remove. Lots of fruits and veggies have rough skin (such as cantaloupe or strawberries) or folds (such as leafy greens) where pathogens can lurk. Contaminants may be present on the surface of fruits a

Fragrant Lindens

Tilia  in bloom American basswood, Tilia americana, a native tree, and the European lime tree  Tilia cordata , are popular flowering landscape trees. They are just finishing blooming now in Minnesota. The fragrant flowers of Tilia  provide nectar for bumble bees and sweat bees, and the foliage serves as a food source for over 150 species of caterpillars. Masting on Tilia Flowers are especially heavy this year on landscape trees, making some trees appear yellow from a distance. This masting or flowering with heavy seed production may have been induced by recent environmental conditions.   Enjoy the fragrance and appreciate the food these trees provide for many of our pollinating insects!     About masting: Author: Mary Meyer, Professor and Extension Horticulturist