Master Gardener Sue Morris: Things to consider when adopting 'No Mow May'
There is no official stance from the University of Minnesota on adopting a "No Mow May" approach to your lawn, in order to provide food for early pollinators. Both Wisconsin and Iowa Extensions recommend adopting a “Mow Less in May” routine.
This spring there has been a lot of buzz about “No Mow May.”
We have had no official stance on this subject from the University of Minnesota, but fellow Master Gardener Becky West found information from the University of Wisconsin and I found about the same view from Iowa State University Extension.
The reasoning behind this is it gives food for the early pollinators before other food is available. Even the city of Edina has adopted the practice and will not penalize homeowners if they do not mow their lawns in May.
"No Mow May" is a conservation initiative started by the U.K.-based organization, Plantlife.
By allowing some of the common flowering plants present in most home lawns to bloom, like dandelion, clover, creeping Charlie, and violet, you can provide more food for pollinators at a time of the year when many other flowers are not yet blooming.
At least one early study showed that unmown yards in the city have a fivefold increase in the number of bees present.
I know if I didn’t mow the lawn and surrounding outbuildings in May, I would have to bale the grass to get if off the lawn if waiting until June to mow.
I don’t spray for dandelions in my yard and it seems the day after I mow, there are new yellow flowers sprouting up all over again.
I don’t believe I have ever had clover blooming in May but have tons of it in the middle of summer.
Here are some things to consider when adopting “No Mow May.”
Most municipalities will issue citations for unkempt lawns — wanting to reduce noxious weeds and manage pest problems like mice or rats, among other things.
The Iowa article stated the grass there will grow at least a foot in the month of May.
It will likely outgrow the flowering plants and once tall enough will smother any plants underneath (and the pollinators won’t be able to find the flowers either).
Ideally you only remove one-third of the total leaf blade in a single mowing. If you take grass from 12-plus inches down to 3 to 3.5 inches, it will cause stress or death of the grass because you are removing so much leaf material at once.
Then there are the grass clippings to clean up. If you don’t remove the clippings, you can kill the plants underneath, leaving bare or open spots in the lawn.
When lawns are not healthy, they develop thin or bare spots. Mother Nature covers the soil in plants and when bare soil is exposed in the lawn, many weeds grow. In summer, these bare spots will be filled primarily by weeds like crabgrass, foxtail, purslane and spotted spurge.
These species do not support pollinators well. When lawns are not mown, it can also promote the growth of weedy and invasive plants that wouldn’t normally grow because they don’t tolerate mowing.
Both Wisconsin and Iowa recommend instead adopting a “Mow Less in May” routine. It has been found that the ideal time between mowing in May would be 10 days to two weeks.
Most flowering plants in lawns, like dandelion and clover, will flower even with mowing.
By extending the time between mowing from every seven days to every 10-14 days, you can continue to manage your landscape in a way that supports the pollinators with more flowers and avoids many of the drawbacks.
The good news is that mowing grass at a taller height promotes a healthier lawn. Mowing at a height of 3.5 to 4 inches promotes a larger, more drought-tolerant root system, can help shade the soil surface reducing undesirable weeds, and allows you to use less pesticide and herbicide on the lawn because the turf is healthier.
Rather than relying on the lawn to provide food sources for bees, install a pollinator garden.
Pollinator gardens with a wide variety of species that bloom from early spring to late fall can help support bees, butterflies, and other beneficial pollinators all season. Trees and shrubs that flower in May also provide food for pollinators.
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.