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Tuesday, May 15, 2018

What to do with ornamental grasses in spring

Mary Hockenberry Meyer, Extension Horticulturist
Gail Hudson, Extension Communication Specialist

Volunteers and Minnesota Landscape Arboretum Gardener Erik Lemke used a gas powered trimmer, rakes, and tarp to move switchgrass tops to the compost pile on May 9, 2018. The other grasses were burned May 2nd before new growth started.
Photo: Mary Hockenberry Meyer
Perennial ornamental grasses, once established, can be one of the easiest plants to grow in your garden. And spring time may be the only time when you'll need to give them a bit of attention.  
Take a good look at your plant. Is the center of it dead? Large mature grasses with a dead center can particularly benefit if they're divided in the spring. 

Friday, May 11, 2018

Do not treat Japanese beetle grubs in spring

Jeffrey Hahn, Extension Entomologist

It is too late to treat white grubs now.  Photo: Jeff Hahn, U of M Ext.
People who experienced Japanese beetles last summer are looking to take action against them this year before they become a problem. However, if you are thinking of treating for grubs this spring it is too late (or too early depending on your point of view).

The bottom line is that grubs are too large to treat now. The best time to treat Japanese beetle white grubs is July through mid-September when they are small or moderate-sized. As they get larger, it is more difficult to kill them and by fall it is no longer practical to manage them. When spring arrives, these grubs are still too large to try to control.

3 Tips to reduce the need to weed

Annie Klodd, Extension Educator-Fruit and Vegetable Production

For most gardeners, weeding is one of the most arduous tasks in the vegetable garden. Save time, save your back, and save your energy: these 3 tips will reduce the need to weed.

1: Mulch in May once the soil has warmed

Thick straw mulch creates a physical barrier to suppress weeds.
Photo: Annie Klodd
Mulch creates a powerful physical barrier to weeds. Common mulch choices for vegetable gardens include straw, grass clippings, and chipped leaves. Apply these mulches liberally to create a 2 to 4-inch mat, which suppresses weeds from germinating and growing. Plant-based mulches have the added benefit of adding valuable organic matter back into the soil.

Landscape fabric also works well to suppress weeds. It is most appropriate for transplanted vegetables, since holes can be cut into it to plant seedlings.

Thursday, May 10, 2018

Giant water bugs just a curiosity

Jeffrey Hahn, Extension Entomologist

This giant water bug was found on the side of a building near a street light.
Photo:  Jeff Hahn, University of Minnesota Extension
Some people are finding a large, up to 2 1/3 inches long, insect outdoors around their homes or their work. Sometimes people think this insect is a beetle, a cockroach, or even an invasive species. In fact, it is the giant water bug, Lethocerus americanus.

This giant water bug is a common native species. It is olive brown with large front legs for grasping and holding prey and large, flattened back legs for swimming.

Tuesday, May 8, 2018

Future engineering gurus plant flowers for pollinators

4H club wanted an experiment and Master Gardener leader came through

Julie Weisenhorn, Extension Horticulturist

4H Engineering Club of Lyon and Lincoln counties
plant annual seeds for the Flowers for Pollinators study

The Lynd Community Center was a bee hive of activity on Saturday, May 5th as 11 members of the 4H Engineering Club of Lincoln and Lyon Counties joined the effort to help pollinators by starting seeds for their own Flowers for Pollinators studies. Five other 4H groups from Redwood county and another in Lincoln county will also participate.

Flowers for Pollinators (F4P), now in its 4th year at various MN sites, asks the question "Are annuals attractive to pollinators?" The 4H club of elementary and middle school youth is led by Extension Master Gardener Stephanie DeJaeghere. The club wanted to conduct some kind of experiment and DeJaeghere had heard about the F4P as an Extension volunteer. 

The club members - and their dedicated parents - started six of the 30 F4P varieties for planting and evaluation in their own gardens:
  1. Dwarf sunflower 'Suntastic bicolor pink' - blooms early, pollen-less yet attracts bees, large pink
    Seed packets and plant labels for the 6 varieties
    to dusky yellow flowers with black centers
  2. Melampodium 'Showstar' - prolific bloomer all season, small gold daisy-like flowers
  3. Zinnia 'Zahara Starlight Rose' - small bushy zinnia, white flowers with rosy center
  4. Zinnia 'Old Mexico' - prolific bloomer; red and gold medium sized flowers
  5. Cosmos 'Double Take' - Blooms more in mid to late summer; pinks and whites
  6. Marigold 'Bambino' - deep gold, medium flowers, low and bushy

They'll be evaluating the plants for insect activity and recording insects visits on the flowers. A F4P blog and an Instagram account (flowers4pollinators) are available for the club members to report their experiences and observations.

UMN Extension 4H Program Coordinator for Lyon county, Sam Jens, was so interested in the study that he and DeJaeghere decided to plant two study sites at the Lyon County fairgrounds.

Follow the progress of the Lyon county 4H Engineering club on the F4P blog!

Saturday, May 5, 2018

Start the season right with healthy plants

Learn what to look for while you shop!

M.Grabowski, UMN Extension 

Coleus for sale at a local garden center
Photo: M. Grabowski, UMN Extension
The first step to prevent disease problems in the garden is to start out with healthy disease free plants.

Many plant pathogens are able to hitch a ride from one garden to the next by infecting plants before they are sold or shared. This can result in disease problems for years to come as the new pathogen becomes established along with the new plant.

Tuesday, May 1, 2018

Reduce the risk of tar spot and apple scab now

M. Grabowski, UMN Extension
Apple scab at mid summer
M. Grabowski, UMN Extension 

Two common leaf spot diseases that blight Minnesota landscapes every year are tar spot of maple and scab of apple and crabapple. Both diseases are caused by fungi that survive winter on last year’s infected leaves.

As snow melts and tree buds begin to swell, gardeners have one last chance to remove these infected leaves before the fungal pathogens become active.

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