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Extension > Yard and Garden News > March 2017

Friday, March 31, 2017

Growing healthy seedlings

M. Grabowski, UMN Extension Educator
M. Grabowski, UMN Extension

As the growing season approaches, many gardeners are starting seeds indoors and making plans for direct seeding in the garden. Unfortunately, damping off, a common disease of seedlings, can dampen dreams of garden fresh produce by killing plants before they get started. Here are a few critical steps that gardeners can take to ensure a healthy crop of sturdy seedlings ready to face the growing season.

  1. Use clean pots. It is o.k. to reuse old pots and trays but wash them first. Scrub out any old soil and plant roots. Soak the pots in solution that is one part bleach and nine parts water for 10-30 minutes. Then rinse in clean water. 
  2. Purchase new potting mix designed for seed starting. Potting mix that has been previously used often contains low levels of plant pathogens. Newly emerged seedlings have little to no natural defenses and quickly succumb to these pathogens. 
  3. Warm the soil with a heating mat designed to go below planting trays. If seeding directly into the garden, wait until the soil temperature has warmed to the optimal temperature for germination (70 F or greater for most vegetables). 
  4. Keep soil moist but not soggy. Seedlings need moisture to germinate and grow but too much water will encourage damping off pathogens. Use a potting mix that drains well. Pots should have drain holes that allow excess water to drain off.
  5. Water with warm water. Cold water slows plant growth and keeps seedlings in a vulnerable stage for a longer period of time. Warm water to 68-77 F before watering plants.

The key to success is to provide seedlings a clean environment and optimal conditions for growth to help them quickly grow out of the vulnerable seedling stage and into a study healthy transplant.

Learn more about Starting seeds indoors
Learn more about Damping off of seedlings

Ants in spring

Jeffrey Hahn, Extension Entomologist

As we transition into spring, ants are starting to become active in and around homes. If you are having a problem with ants, the first step is correct identification of them. This is important because there are a variety of ants that may be seen. Different species have different nesting sites, food preferences, potential for damage, and other habits which require different methods of control. Treating ants is not one size fits all.
Carpenter ant, a common ant in Minnesota.  Note the one-
segmented petiole.  Photo: Jeff Hahn, U of M Extension

The most common ants seen in Minnesota are carpenter ants and pavements ants, although other ants, including yellow ants, odorous house ants, and thief ants can also be found. Identifying ants can be challenging, especially because of their small size.

When identifying ants, first determine how many segments the petiole (the section connecting the abdomen with the thorax) is, one or two. Then depending on the ant, other characteristics such as the shape of the thorax, number of segments in the antennae, and presence or absence of spines, can also be important. Be careful about using size and color to identify ants as that is often not an accurate method. If it is not apparent what kind of ant is being encountered, submit a sample (which could also be a picture) to an expert for identification.
Pavement ant, a common ant in Minnesota.  Note the two-
segmented petiole.  Photo: Jeff Hahn, U of M Extension

Once the ants have been identified, it is easier to understand the options available for controlling them. Good sanitation can help reduce the number ants that are attracted indoors. Keep kitchen surfaces clean, rinse recyclable containers before storage, and regularly take out kitchen garbage. Keep in mind that if the ants are nesting indoors (probably true when ants are sighted this early in the spring), this may not reduce the number of ants that are seen.

The best method for controlling ants is delivering a toxic dose of insecticide into their nest. Spraying the ants that are seen foraging around your home is a short term solution that does not affect the nest. Just a small number of workers from the nest are out searching for food so it is not possible to destroy it through attrition.

Depending on what ant is present, it may be possible to apply an insecticide directly into the nest. This becomes more complicated when the ants are nesting in out of the way places, like wall voids or under concrete slabs.

Sometimes the most effective treatment is baiting them. The foraging workers consume the bait; take it back to the nest where they share it with the other ants. If enough bait is taken back to the nest and the queen is also killed, the nest can be eradicated. However there are a variety of factors that can influence the success of baits, e.g. they are not attractive to the target ants, there are competing food sources, more than one nest is coming to the bait, and not enough bait is available, so baiting may not always be effective.

If ants continue to be a problem despite the steps taken by a resident to control them, they should consider contacting a professional pest control company to treat the ants. They have the experience and access to the necessary resources to more effectively control ants.

For more information see What to do about household ants  and Carpenter ants.

Tuesday, March 28, 2017

Educational Opportunity: Low Maintenance and Environmentally Friendly Lawns

Minnesota State Horticultural Society and University of Minnesota Extension Present: 

Low Maintenance and Environmentally Friendly Lawns
Saturday, April 8, 2017 - Saturday, April 8, 2017  9:30am - 12:00pm
University of Minnesota
1970 Folwell Avenue, Alderman Hall, Room 405 St. Paul
Fees:           $30 Members, $35 Nonmembers

Low Maintenance and Environmentally Friendly Lawns –limit 75
Saturday April 8, 9:30 a.m. to noon.
Join us at 9 a.m. for coffee
$30 members, $35 nonmembers
Location: Alderman Hall Room 405, UMN, 1970 Folwell Avenue, St. Paul, MN 55108 
Parking: the upper Buford Circle parking lot (#S106 on map)
While our neighbors might be pushing for a perfect manicured lawn, many of us want to embrace a reduction in water use, fertilizer applications, and pesticide inputs and still have a decent looking lawn.  Can we have both: perfect and low-maintenance?  The answer is yes, but it all starts from the ground up.  Join us for a morning with a local expert and find out how you can be a good steward of the environment and have a good lawn. Turfgrass species selection, soil types and preparation, fertility and watering practices, and pest management will be discussed.
Sam Bauer is a U of MN Extension Educator. His research revolves around practical management strategies to improve the performance of turfgrass, specifically as it relate to low maintenance grasses, water conservation, and nutrient and pesticide loss.

Friday, March 24, 2017

EAB discovered in Goodhue County

Jeffrey Hahn, Extension Entomologist

The following is based on a recent news release by the Minnesota Department of Agriculture.

The Minnesota Department of Agriculture (MDA) has placed Goodhue County under an emergency quarantine after emerald ash borer (EAB) was found in the city of Red Wing earlier this month.

An MDA employee noticed an ash tree with significant woodpecker damage, a tell-tale sign of possible EAB infestation, during a hike over the weekend at Barn Bluff. She took photos of the tree and noted the location. After further investigation, the MDA found EAB larvae in the tree. Today the USDA officially confirmed the insect to be emerald ash borer.

There are several things residents should look for when checking for emerald ash borer.

• Be sure you’ve identified an ash tree. This is an important first step since EAB only feeds on ash trees. Ash have opposite branching – meaning branches come off the trunk directly across from each other. On older trees, the bark is in a tight, diamond-shaped pattern. Younger trees have a relatively smooth bark.

Now is a good time to look for woodpecker
pecking on an ash as this often indicates an
EAB infestation.  Photo: Jeff Hahn, U of M
• Look for woodpecker damage. Woodpeckers like EAB larvae and woodpecker holes may indicate the presence of EAB.

• Check for bark cracks. EAB larvae tunneling under the bark can cause the bark to split open, revealing the larval (S-shaped) tunnels underneath.

• Contact a professional. If you feel your ash tree may be infested with EAB, contact a tree care professional, your city forester, or the MDA at or 888-545-6684 (voicemail).

Minnesotans can also help stop the spread of EAB by burning firewood where you buy it and don’t transport it. Look for wood that is MDA certified as heat-treated to ensure it is pest-free.

Because this is the first time EAB has been identified in Goodhue County, the MDA is enacting an emergency quarantine to limit the movement of firewood and ash material out of the county. This will reduce the risk of further spreading the tree-killing insect. Currently 14 other Minnesota counties are under quarantine to prevent the spread of the emerald ash borer.

Emerald ash borer larvae kill ash trees by tunneling under the bark and feeding on the part of the tree that moves nutrients up and down the trunk. The invasive insect was first discovered in Minnesota in 2009 and is now found in 30 states.

For more information on EAB, see the University of Minnesota Extension fact sheet Emerald ash borer in Minnesota

Go here to see the original MDA news release.
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