Home Lawn Care Newsletter | April 2023

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Welcome to the latest issue of the Home Lawn Care Newsletter from UMN Turfgrass Science! We will provide up-to-date information to address all your lawn care tasks at the times when you need to know.

a lawn with white clover

Apr 14, 2023: Issue 10

April’s news has gone to the dogs!

What grass is really best for dog spots?

Now that the snow on our lawns has melted, many brown spots randomly spaced around the lawns of dog owners begin to show themselves. We get lots of questions about which type of grass seed is best for repairing dog urine damage. It is generally understood that excess nitrogen in dog urine in a concentrated spot is what causes dead brown spots. Recent research suggests lactic acid to also play a part.

For cool-season grasses, tall fescue has the most tolerance to both of these factors, then creeping red fescue, perennial rye and Kentucky bluegrass. There are many varieties of turf-type tall fescues that are terrific replacements for or additions to Kentucky bluegrass and are very similar in appearance. Turf-type tall fescue is very tolerant of foot traffic, but it’s more drought tolerant, needs less mowing, and it grows well in sun or moderate shade.

Turf-type tall fescue is a bunchgrass, however, and doesn’t fill in damaged areas as quickly as Kentucky bluegrass. A way to work with that is to add Dutch white clover to your seed mix. This clover fills open spots because of its stoloniferous growth habit, is tolerant of excessive nitrogen, requires very little water, and needs to be mowed less frequently, similar to turf-type tall fescue. Combine turf-type tall fescue with Dutch white clover for a low-maintenance, resilient grass that kids and dogs alike will enjoy.

Can I use artificial grass in a kennel instead of grass?

a dog in a kennel with artificial turf

Artificial grass can be used in a kennel, or separate area of the lawn for the dog’s potty stops. It’s easily rinsed down if necessary and there are no maintenance tasks. Recent research shows however, that the temperature of artificial grass can be at least double that of natural turf in the sun. If you choose artificial turf for an area for your dog, make sure the area is shaded. Cooling the artificial turf by watering it can be wasteful.

Time to think about crabgrass

When can I put down crabgrass pre-emergent?

a dashboard view with several tools including a map of Minnesota

Timing when to put down crabgrass pre-emergent herbicides is getting easier by the year. Pre-emergents are a type of herbicide that are only effective if they are applied before crabgrass germination. The University of Minnesota Turf Lab has a tool called Dashboard that uses local weather stations near you to help identify the best time to apply a pre-emergent herbicide. It is as simple as dropping the pin in your location and selecting “Crabgrass PRE timing” under the “Weeds” tab. Our forsythia bloom peak is a pretty good indicator of pre-emergent application as well. Due to the sudden warm-up the second week of April, much of Minnesota has already had soil temperatures near to the 55 degrees that crabgrass requires for germination, so some post-emergent control of summer annuals like crabgrass may be needed. 

White clover for lawns and pollinators

Shortcut to a lower maintenance lawn that bees love

Farmers have long known about frost seeding, a method where seed is planted in very early spring before the growing season starts. It’s ideal for seeding Dutch white clover into soil that is clay or loam, but is not recommended for sandy soil. The ground needs to be clear of snow, with night temperatures at 20 degrees and day temperatures around 40 degrees. Grass height for frost seeding is most effective around 2 inches – enough to have some open soil for the seed to reach it. Spread your clover seed over the existing lawn. The freeze/thaw cycle of the season will settle the seed into the soil, and you’ll be on your way to naturally fertilizing your lawn, doing less watering and having a nice green color in your lawn throughout the summer.

Is it true that I can do my whole lawn over in clover?

You can, with some caveats. Dutch white clover is a definite option for lawns in Minnesota. It prefers cool and moist soil, but will tolerate many conditions. This is a short-lived perennial for us and can be seeded with 1 to 3 pounds per thousand square feet, using a process similar to seeding or overseeding a regular turf grass lawn. You may want to overseed a full-clover lawn every three years or so to keep it dense. Dutch white clover grows assertively by stolons. It does best, however, when combined with a low-maintenance turfgrass when you need a lawn that can handle foot traffic. For greater wear tolerance, blend with turf-type tall fescue, and for moderate wear tolerance, try a fine fescue mix. Check out the great research from UMN to choose the right grass seed for you. 

Research highlights

Is not mowing in May a good idea?

a campus lawn near a building that has not been mown

No Mow May refers to a movement to promote pollinators in home lawns by not mowing at all in May. The concept has actually been around for several years in the Northeast US, but it was launched into popularity from a research article claiming that not mowing in May resulted in higher pollinator populations in lawns in Wisconsin. Although this research paper has since been retracted by the journal due to some issues with the methodology, city councils are still voting to support the initiative. 

Turfgrass Extension Educator Jon Trappe took part in a presentation on Slow Mow Summer with the University of Minnesota Bee Lab. They discussed what No Mow May might mean for pollinators and our lawns in Minnesota. It is unclear if there is a benefit to pollinators by not mowing in May and there are likely other more productive things you can do to promote pollinators. May is typically the month when turfgrasses are growing the most so not mowing can lead to problems like excessive clippings and mowing too short, which may stress the lawn going into summer.

If you want to promote pollinators in lawns, consider planting a bee lawn. The Flowering bee lawns tool kit and UMN Extension's Planting and maintaining a bee lawn are great resources for more background on pollinators and how to grow and maintain a bee lawn.


We will be at these events to answer questions on smart irrigation and lawn care as part of our collaboration with the Metropolitan Council.


Image credits: Kim Sullivan (#1 and #2); Jon Trappe (#3 and #4)

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