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Extension > Yard and Garden News > March 2018

Saturday, March 31, 2018

Spring seed starting: Try the rag doll method!

A family-friendly gardening technique

Want to make sure your seeds are viable? Try the "rag doll" seed starting method. It's a great thing to do with kids--and they can easily see results.  UMN Extension Educator Julie Weisenhorn and one of her best friends demonstrate for us.

And for information about starting seeds indoors, go to:

Thursday, March 29, 2018

Spring garden design project in mind?

Julie Weisenhorn, UMN Extension Educator

Ah, spring at last! If you're like me, you are itching to get out into your garden. This period of fluctuating weather (warm one day, snow the next) is a great time to stay indoors and do thinking about your next great garden design project. Start with these five considerations of sustainable design (in order of importance) and how they apply in your landscape:

  1. Functionality - What do you have to be able to do in your landscape? Some common functions are entertaining, play area, pet areas, grow vegetables, have a fire pit (and haul firewood to your fire pit), access to all areas of your landscape.
  2. Maintainability - Be able to maintain your yard and garden at the level you desire. Common landscape maintenance aspects include mowing, pruning, shoveling and storing snow (ugh), maintaining structures.
  3. Be environmentally-sound - Promote a positive effect on the surrounding environment (vs. harming it) by choosing plants that will thrive - not just survive - in your landscape and thus remain stress-free, pest-free and healthy. This will result in fewer inputs such as pesticides, less water waste, less work for you and a better looking landscape overall.
  4. Cost-effectiveness - Have a landscape you can afford financially and from a time allocation aspect. Summer is short enough in Minnesota without spending all your free time maintaining your yard and garden (unless you're into that kind of thing like I am). Create a landscape that will keep your personal inputs (money, time, work) in achievable bounds.
  5. Visually-appealing - What you want to see when you are in your yard and garden. This is where the fun and creative aspects of garden design bloom. Collect ideas from magazines, websites, home and garden shows, public gardens, garden tours. Think how you can incorpoate some of these into your little slice of paradise.
If you are still wishing you had more help, take part in our Landscape Design Basics for Homeowners workshop on Saturday, April 14, 2018, 8am - 5pm on the U of M St. Paul campus. At this workshop, we walk you through the design process with the goal of helping you to have a healthier, better functioning and maintainable landscape. The day-long workshop includes hands-on exercises on bubble diagrams, plant selection, concept lines, and draft design. There's still space available! Register  here: MSHS Northern Classes & Events

Monday, March 26, 2018

April to-do list for vegetable gardening

Early preparation = fewer weeds

Annie Klodd, Extension Educator-Fruit and Vegetable Production

Tomato and pepper seedlings should be started
in April for late May transplanting. Photo: Julie
Are you ready for the 2018 vegetable gardening season? This new and ongoing series of monthly articles will lay out what to do during each month in the garden, to produce an abundance of fresh, healthy vegetables.

In April, the to-do list includes starting seeds indoors, getting the soil ready, and planting early or "cool-season" crops like asparagus, potatoes and onions.

Starting seeds indoors

Certain vegetables perform best when the seeds are sowed indoors in mid-spring, grown into seedlings for several weeks, and planted outside once the threat of frost has passed. These include warm-season crops like peppers, eggplants, and tomatoes, which all require warm temperatures and a long growing season to produce vegetables.

Gardeners can choose to start their own seeds indoors in the spring or purchase transplants from a supplier several weeks later, to plant directly into the garden.

Friday, March 23, 2018

How to prune apple trees: A 3-part video series

Produce more high quality apples by pruning

Annie Klodd, Extension Educator-Fruit and Vegetable Production 

Perhaps you've recently planted some apple trees, and you are ready for the next steps to help them produce a healthy crop of fruit.  Or maybe you just moved into a home with a couple of trees in the yard. Either way, pruning will be a crucial part of caring for these apple trees. 

Why prune? 

Pruning is essential for reliable fruit production from year to year. If left to their own devices, apple trees will develop dense canopies and many small fruit with uneven ripening, reduced quality, or generally lower productivity. Pruning focuses the tree’s energy into producing larger, higher quality apples and increases airflow through the tree, reducing disease potential.

How to prune an apple tree

Last month, we went outside to the apple orchard at the University of Minnesota Horticultural Research Center to film a three-part video series on pruning apple trees called "Apple Tree Pruning Made Easy." Thank you to David Bedford and Emily Tepe for assisting us in this effort. You can watch by clicking on the video boxes below:

 Apple Tree Pruning Part 1: 

Apple Tree Pruning Part 2:

Apple Tree Pruning Part 3:

Videos produced & edited by Gail Hudson, UMN Extension Communications Specialist

Wednesday, March 14, 2018

Last Chance to Prune Oaks

M. Grabowski, UMN Extension Educator

Fresh pruning cuts on an oak tree.
M.Grabowski, UMN Extension 
If you have oaks in your landscape that need pruning and you live in an area of Minnesota where oak wilt occurs, pruning must be done before the oak wilt fungus and it's insect vector become active. Oak wilt is a fatal disease of oak trees that can be found in some counties of Minnesota. If you live in an area where oak wilt occurs, it is critical to prune oak trees before the high risk infection period begins in April. The risk status for oak wilt is updated as weather conditions change, but in a normal year high risk of oak wilt infection occurs in April, May, and June. Check in with My MN Woods to find the current oak wilt risk status before you prune.

Oak wilt has been found within
20 miles of all areas colored pink
Oak wilt is caused by a fungal plant pathogen. Spores of the oak wilt fungus are carried by sap feeding beetles in the Nitidulidae family. These small beetles are attracted to wounds and fresh cuts on oak trees. When they arrive at the cut branch, spores of the oak wilt fungus are knocked off and can infect the open wound.

Red oak trees are highly susceptible to oak wilt and can wilt and die in as little as 4 weeks after infection. Once infected with oak wilt, there is no way to save a red oak tree. White and bur oaks can also become infected with oak wilt. These trees are able to slow the infection but will eventually succumb to the disease in a few years. Some treatment options are available for white and bur oak trees if the disease is identified at the early stages.

Friday, March 2, 2018

Prune out cankers and galls now

Michelle Grabowski, UMN Extension Educator
Black knot gall on a wild cherry tree.
M. Grbaowski, UMN Extension

An important late winter gardening task is pruning to remove diseased branches. Winter is the best time to prune for several reasons. Diseased and damaged branches are easily seen when leaves are not present. Winter temperatures are not ideal for the fungi and bacteria that cause disease in trees and shrubs. The pathogens will still be present but at much lower levels than during the growing season. By pruning out infected branches now, gardeners can significantly reduce the risk of the disease spreading within the plant and to neighboring plants once the growing season begins.

Several types of disease can affect branches of landscape trees and shrubs.

Gall rust on a pine tree. M. Grabowski,
UMN Extension
A gall is an unusual overgrowth of plant tissue caused by a pest or pathogen. Fungi and some bacteria can cause galls to form on branches of trees and shrubs. Galls can be round, oblong, or irregular in shape. They are made of wood but may have discolored bark due to the infection. Galls can girdle a branch and kill all leaves and shoots beyond the gall. Some trees and shrubs will tolerate galls and will not suffer any damage as a result.

Golden canker causes the reddish purple
bark of pagoda dogwood to turn yellow.
M. Grbaowski, UMN Extension 
A canker is an infection of the sapwood and living bark caused by a fungal or bacterial plant pathogen. Cracked, discolored, or blistered bark in an isolated area of a branch indicate that there is a canker. In some trees and shrubs a thick hard layer of resin or sap may cover the infection. If the bark is peeled back, reddish brown discoloration of the wood can often be seen.

A canker will eventually grow to encircle the branch, cutting off the flow of water and nutrients. This results in death of the branch, and any shoots and leaves beyond the canker. In some diseases, the canker can progress into the main trunk and result in death of the tree.

Make the pruning cut a minimum of
4 inches below visible symptoms at
a branch union. M. Grabowski,
UMN Extension 
How to prune out cankers and galls
First examine the tree carefully to find any branches with discolored, cracked or blistered bark or with any unusual tumor like growths. The infection will extend beyond the visible discoloration of the bark so the pruning cut should be made at a minimum of 4 inches below symptoms of disease. The tree will heal the pruning cut most rapidly and easily if the cut is made just above a bud or a branch union.

All branches with galls or cankers should be removed from the area and burned or buried. Pruning tools should be cleaned with undiluted Lysol (active ingredient .1% alkyl dimethylbenzyl ammonium saccharinate) or a 10% solution of household bleach in water.

Your Winter Garden: Pest tips for houseplants

By Julie Weisenhorn, Extension Educator - Horticulture

Just like in our summer gardens, we need to keep an eye out for pests in our indoor winter gardens (houseplants). Pests may sometimes hitchhike on houseplants that spend the summer outdoors, and emerge in the warmth of our homes. New plants may also bring in new pests. Insect eggs laid on the underside of leaves or in the soil may hatch indoors and suddenly appear too.

Hand showing plant debris accumulated on the soil of a potted plant.
Remove plant debris
Tips to reducing pest issues in your winter garden:

Groom plants that come in from the outside. Clear away dead plant debris (leaves, flowers) and prune off dead or overgrown stems and branches. Remove dust that can filter light by wiping off leaves with a soft, damp cloth or spraying the plant with water.

Scout for signs and presence of pests.
Look at the undersides of leaves and along edges and the bottom of  pots for insects and egg masses and remove or treat. Shiny, sticky leaf surfaces (honeydew) can be a sign of sucking insects like scale and aphids. Fine webbing is a sign of spider mites. Household insects

Some plants may be outgrowing their containers and need re-potting. 
Take this opportunity 
to check the underside of the plant as well as
roots, and to prune off any roots that are dark brown and mushy.
Re-pot plants in fresh, sterile soil and a clean pot.
Use fresh soil and a clean pot.

Give new plants plenty of space. Quarantine new plants for a couple of weeks away from your current, pest-free plants to make sure the new fella is pest-free too.

Follow pesticide labels. Many pests can be eliminated from houseplants by hand-picking, wash or a blast of water. If you do choose to treat with a chemical, use one for houseplants and follow all pesticide label precautions. This is especially important with indoor plants as they live where we live. Household Insect Control
    Examine all parts of plants.
    Cottony scale on orchid
  • Look to treat outside on one of those warm winter days or in a ventilated garage. 
  • Bag the plant in a plastic garbage bag, and poke a small hole in the bag for your spray nozzle. Then spray, apply a piece of tape over the hole, and let the plant site covered. Remove the bag when the plant is dry. This contains the pesticide till dry and protects furniture and walls from spray. 

Thursday, March 1, 2018

Perfect Timing for Pruning Your Apple Tree

Produce more apples

By Gail Hudson, Extension Communications Specialist for Horticulture

Photo courtesy: Julie Weisenhorn
By the end of the winter, most gardeners are itching to get outside and start doing something! You certainly can--by pruning your apple tree(s). Extension Educator Annie Klodd, a fruit and vegetable specialist, says late February, early March is just about right for Minnesota gardeners. The trick is to do it at the end of winter just as the temperatures are rising a bit, but before the tree's buds emerge. 

Pruning an apple tree is an important task for home growers, she says, for several reasons: 
  1. It's a good time to get rid of diseased, damaged and dead wood on your tree.
  2. It gives the apple tree a nice shape and allows more light to get to the buds and fruit.
  3. The tree will be healthier, produce more fruit and grow better overall. 

Tools to use

Line up the right tools before you begin pruning. Depending on the size of your apple tree, you'll need at least a pair of hand clippers for a small one.  For a large tree, large loppers work as well as a pruning saw.

For more information about growing and maintaining apple trees, read this article by University of Minnesota Horticulturist and fruit expert Emily Hoover:

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