Master Gardener Sue Morris: 'No Mow May' well-intended as benefit to pollinators but exercise care with lawn
'No Mow May' is well-intended — to provide flowers for early season pollinators — but after that month of growth, mowing more than one third of the plant’s tissue can harm the lawn.
Do you remember hearing about “No Mow May” a few years ago? This was a practice that started in England and was brought over to this country.
The idea of not mowing a lawn during the month of May was to provide flowers for early season pollinators when there was little else for them to eat.
Several cities in Minnesota have scaled back mowing ordinances for the month of May — and have even created lawn signs for promoting the movement.
Jon Trappe, turfgrass educator with University of Minnesota Extension, has been doing some research on this and said that people have reached out to him to see if he would support a mandate outlawing mowing in May.
He reports that he fully supports promoting pollinators in the landscape but he wanted to let the public look at what not mowing in the month of May might mean for your lawn.
Lawns in Minnesota are made up of several cool-season turfgrasses that naturally have two flushes of growth in a given year and those typically happen in early summer and early fall. We recommend many lawn management practices around these times of year because they are essential for promoting a healthy and climate resilient lawn.
In Minnesota, not mowing in May means the lawn is not mowed for the first time until June, by which time the grass can get to 12 to 18 inches high. This creates many practical challenges for homeowners for mowing down to more ideal mowing heights, such as having to compost the clippings off site.
Mowing more than one third of the plant’s tissue in a single mowing event is known as scalping and can harm the lawn. This can stress the lawn going into June and then record high temperatures could stress the lawn even more.
Keep reading below the related content for more of this week's column from Master Gardener Sue Morris.
If you want to promote pollinators in your lawn for the month of May while ensuring a healthy and resilient lawn, he recommends mowing as high as your mower will allow and only as needed to avoid mowing more than a third of the height. For example, if you are mowing at 4 inches, you would want to mow when the lawn gets to about 6 inches.
Since I live out in the country, I have millions of dandelion seeds blowing in every year. I don’t spray them as I worry about the cats and wildlife that travel across the yard.
Consequently, I have an abundant supply of those yellow flowers. Each time I mow lawn, by the next day they are back in full bloom.
The same can be said for wild violets. I have clover in my lawn too but that doesn’t bloom until later in the year.
Don’t forget that the apple trees are in full bloom in May and they provide great food for pollinators while they are pollinating your blossoms.
Mulch clippings as you mow to return those nutrients to your lawn.
If you want to help the pollinators, you can plant a pollinator garden. I have a large patch of Virginia bluebells that bloom at apple blossom time.
What I like about them is they are ephemeral: That means after they finish blooming, they dry up and disappear until the following spring.
By that time hosta are full emerged and fill the space.
Master Gardener Sue Morris has been writing this column since 1991 for Kandiyohi County newspapers. Morris has been certified through the University of Minnesota as a gardening and horticulture expert since 1983. She lives in Kandiyohi County.