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Extension > Yard and Garden News > June 2018

Wednesday, June 20, 2018

Spot check: look for tomato diseases now

Tomato leaf spot diseases are just beginning to appear on Minnesota tomato plants. Haven’t seen them yet? Take a closer look.

M. Grabowski, UMN Extension Educator

Most leaf spot diseases in tomato overwinter in the soil and then splash on to the lower leaves of the plant. As a result the first leaf spots can be found on the lowest leaves. To find them you may have to push aside the upper leaves and peer down at the leaves closest to the ground.
Young tomato plant with lower leaves infected with a leaf spot disease.
M. Grabowski, UMN Extension

Tuesday, June 19, 2018

Be on alert for squash vine borers in your garden

Jeffrey Hahn, Extension Entomologist

Male and female squash vine borers on a date.  But make no
mistake, they are looking for your garden when they're done. 
Photo: Jeff Hahn, University of Minnesota Extension
If you are growing squash or pumpkins in your garden be on the watch for squash vine borers. They are beginning to emerge and may be in your garden soon!

Adult squash vine borers are wasp-like moths that are active during the day. They are about 1/2 inch long with an orange abdomen with black dots. The first pair of wings is an iridescent green while the back pair of wings, which is sometimes hidden, is clear.

There are a couple of methods for detecting them. Watch for them flying around while you are in your garden; they are conspicuous and easily noticed.

You can also place yellow containers (like pans or pails) half filled with soapy water. These moths are attracted to yellow; when they fly to the container, they fall in to the water. Then just check the container for moths.

As soon as you spot one squash vine borer, start management. If you don’t see any but have a history of these pests in your garden, take action by late June or early July (the further north you are located, the later the moths will emerge).

The larvae are a serious problem; they cause wilting and eventually death to plants. You can exclude the adults from laying eggs by using a floating row cover. There are also a variety of insecticides that you can apply, such as permethrin or carbaryl, to help discourage them.

For more information, including management, see Squash vine borer management in home gardens.

Friday, June 15, 2018

Get Smart & Save $$ watering your landscape this summer!

Gail Hudson, Extension Communications Specialist

Do you have an electronic controller for your yard and garden's irrigation system? Save money for your summer vacation and install a Smart Controller!

Smart Controller's are easy to install and operate (using a phone app). You can water your landscape based on the weather (Will it rain today? Did it rain yesterday?) and how much moisture there is in the soil.

Extension Educators and Turf Specialists Sam Bauer and Brian Horgan walk you through the basics in this excerpt from "Green Grass With Less Blue," a joint video project with the University of Minnesota Extension and the Metropolitan Council.

Water less and save more!

Aggressive weed challenges MN gardeners: Japanese knotweed

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

Japanese knotweed plants produce female flowers and need a pollen source.
However, the plant spreads primarily through rhizomes (underground stems).
Photo: Mn Dept of Agriculture

Is it the buckthorn of weeds? Beware, this weed is so aggressive, it can even damage pavement! 

This large, fast-growing, shrub-like plant is commonly called Japanese knotweed or Mexican bamboo (Polygonum cuspidatum), which can grow from 3 to 9 feet tall with leaves that are six inches long and four inches across.

It is a tough weed to control thanks to its large system of fleshy, underground rhizomes (stems) as big or bigger than your finger, which can extend up to 5 feet from the plant.  Above ground, the hollow, bamboo-like stems can become tough and woody with age.

Learn how to control or reduce its presence by clicking on "Read more"...

Thursday, June 14, 2018

Ants in turf

Jeffrey Hahn, Extension Entomologist

Ants in lawns has been a common question lately. This insect is one of the most common insects we see in our landscape. Although they do not injure or kill turf, they can be a nuisance from their presence.

Field ants nesting around  a basketball hoop. They are not
injuring the grass but some may find this a nuisance and
unacceptable.  Photo: Jocelyn McDonald

Wednesday, June 13, 2018

Watch out for Lyme disease!

Jeffrey Hahn, Extension Entomologist

Blacklegged (deer) ticks.  Top row: adult male and female.
Bottom row: immature nymphs.  Their small size, especially the
nymphs, makes it more difficult to see them and more likely to be
exposed to Lyme disease. Photo: Jim Occi, Bug Pics,
Although you can encounter blacklegged ticks (also known as deer ticks) nearly any month of the year, June and July are the times of highest risk for becoming infected with Lyme disease. That is because summer is when the immature nymphs are active.

 Because of their very small size, it is easier to be bitten and not know it.
Learn about ticks--where they live and the symptoms of Lyme disease. Just click on "Read more."

Friday, June 1, 2018

Video: Are you over watering your lawn? Most people do, and don't even know it!

Save water, lower your bill and help the environment

Gail Hudson, Extension Communication Specialist

Photo: Gail Hudson, UMN Extension
Summer has quickly arrived, and already we've turned on our irrigation systems...leaving them to run throughout the season.  Typically, these systems are set on an odd-even schedule. But are you watering too much?

Click on "Read more" for the video...

Don't wait to diagnose spruce problems

Now is the time to treat for spruce needle cast diseases. Do you know what’s wrong with your spruce and how to treat it?  

M. Grabowski, UMN Extension Educator

Spruce tree suffering from Rhizosphaera Needle Cast.
M. Grabowski, UMN Extension
Many spruce trees across Minnesota have brown or missing needles along with dead branches. This damage can be caused by a variety of problems including needle cast or needle blight diseases, branch cankers, insect pests, mites, or environmental conditions.

Although management options are available for many of these problems, each problem has its own unique solution. The first step in correcting a spruce problem is getting a correct diagnosis.

Lawn still looking winter ragged? E-Z steps to repair your turf

Video: "Spring Lawn Repair"

Gail Hudson, Extension Communications Specialist

Winter damage to predominantly fescue grass lawn.
Photo: Gail Hudson
Remember the blizzard that hit Minnesota in April? Just a month or so later, the snow has melted and the winter has turned into summer heat, leaving behind brown spots on our lawns.

Recent rains have helped green things up...but you can do more to repair the winter damage with some easy steps.
Click "read more" to get to the video tips...

Be a pollinator champion

Help researchers study rare and declining pollinators

Elaine Evans, Extension Educator

Volunteer with a male bumble bee. Males can't sting!
Photo: Jen Larson
Are you aware that bees and other pollinators play a crucial role in keeping food on our plates and on the plates of countless other creatures who depend on the plants they pollinate? 

Have you planted more flowers to help pollinators and taken other steps to make your yard more pollinator friendly?  

If so, you may be ready for the next step: help us learn more about rare pollinators by volunteering to monitor their populations. The more rare a species becomes, the more difficult it is for researchers to find the information needed to protect them. 

Here are three ways you can help monitor rare pollinators this summer...

June To-Do List for Vegetable Gardening

Weed control, vegetable trellis options, watering guidelines & more! 

Annie Klodd, Extension Educator – Fruit and Vegetable Production
Cantelope beginning to bloom on May 30, 2018.
Photo: Annie Klodd
June is an exciting month for vegetable gardeners. With many plants in the ground, this is when we enjoy watching them shoot up in size and give rise to blooms that will produce delicious vegetables.

There is plenty to do in June to make sure our plants grow their best. Tasks include late planting, trellising, weeding, watering, and mulching.

Brown foliage on your maple trees & American elm?

Look may be seeds! 

Mary H. Meyer, Extension Horticulturist and Professor, Horticultural Science

Maple on left with masting, after distress. 
Abundant seed or fruit set in long-lived trees is called a mast year or masting. This year seems to be a mast year for maple and elm in Minnesota. 

Environmental cues or ideal pollination conditions could cause this huge seed production. Moisture and temperature are sensed by trees and their internal switches enable massive flowering followed by seed production. 
Excessive seeds at top of a maple tree.

Watch for carpenter ants this spring

Jeffrey Hahn, Extension Entomologist

Typical carpenter ant.  They are identified by having a one
segmented node and an evenly round thorax when viewed in
profile.  Photo credit: Jeff Hahn, U of MN Extension
Carpenter ants are the most important ant pests found in Minnesota. They can be a problem when they nest in homes and other structures. Because nests are in wood and other hidden areas, it is challenging to know where they are located. Finding the nest and treating it is the best control for carpenter ants.

Always verify that you have carpenter ants. While, people often think of carpenter ants as “big, black ants” (which they are, up to almost ½ inch long), some carpenter ant species are red and black and are smaller, only 3/16th inch long. Some species of field ants, a nuisance species, are black and a similar size to carpenter ants.

Finding carpenter ants in your home in the spring can mean that a nest is present, especially when persistent numbers are found. If you find a swarm of winged carpenter ants indoors, that is a sign of an indoor nest. However, if you find just a few carpenter ant queens (winged or wingless) in your home, they probably just wandered into your home accidentally and no nest is actually present.

A wingless carpenter ant queen.  Finding one or two in your
home (like the author did) is not an indication of a nest
although she is looking to start a nest.  Photo credit:  Jeff
Hahn, Univ. of  Minnesota Extension
If you are having problems with carpenter ants in your home, it is very challenging to eliminate them yourself. For control to be effective, it is necessary to deliver insecticide into the nest to kill the queen and the workers. Killing the foraging workers you see does not impact the nest.

Baits can be effective for some ant problems. However, the ant baits available to residents are not sufficiently attractive or effective to successfully eliminate a carpenter ant nest.

The best control for carpenter ants is to contact a licensed pest management service to treat the nest. An inspection is important to find the foraging trails and if possible the nest(s).

There are several options for treating the nest. Many technicians use a non-repellant residual insecticide, such as Termidor, sprayed around the building’s exterior. The carpenter ants pick up the residue and take it back it to the nest where it gets spread through colony, ultimately eliminating it.

Technicians may also set out baits to control carpenter ants. They have access to a variety of baits and have the experience to use them. It is not unusual for technicians to use more than one bait to be successful. Remember that baits take time so be patient and allow carpenter ants to take enough back to control the nest.

Carpenter ants tunnel and nest in wood.  Control them to
prevent damage to your home.  Photo credit: Jeff Hahn,
Univ. of MN Extension
If the exact location of the nest is discovered, it can be treated directly with a dust. This may require drilling into walls or injecting dust through outlets.

Once treatment has been applied, a technician needs to evaluate how successful the initial control was and whether any additional steps are needed.

However, treating the entire house multiple times on a scheduled basis is considered excessive and less effective. Treatment should be targeted and as specific as possible.

For additional information, see Carpenter ants.
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