Is “No-Mow May” beneficial?
I heard that “No-mow May” is more harmful than reducing the amount of mowing, or “Low-mow May”, which would increase the number of pollinator plants in the lawn. Which is correct?
The answer to your questions of no-mow vs low-mow May is that “It depends.”.
The purpose of both is to lessen the mowing in spring. By letting the grass grow a little before we are past the potential for frost we allow the pollinators who wintered in the “duff layer” of the lawn to get more time to begin their progression into the summer and give them protection should we have cold nights. In addition, many annual/perennial flowering weeds get a chance to bloom so that is food for the pollinators. In an especially dry spring in my yard, I don’t mow until about June 10th and I have forget-me-nots, bluets, dandelions, and clover all blooming. There is even a patch of thyme that has flourished and when we mow, we mow around it.
The downside is that in lawns that have been richly fertilized, there is the potential for such lush growth that when you do mow you end up with thick clumps of grass that might then mold or you could have the potential for tick habitat.
If you have been regularly fertilizing your lawn, using a lawn service, or using a pre-emergent weed killer then mow in May when the grass gets 4″+ and mow higher (3″-4″)/less often.
If you have a lawn that is “lean” (no lawn service/regular weed and feed applications) and don’t mind the look of a few “weeds” in the grass then go for No-Mow May and enjoy the rewards of pollinators and wildflowers. Then mow high and less often starting in June. Or consider doing different things in different parts of your lawn. At our house our side and front lawns are small so we mow in May but the whole backyard is left to the pollinators.