For Virginia, Less-Mow April is better than No Mow May, Virginia Cooperative Extension recommends

Each May, millions of people preserve the blooming dandelions and clover in their lawns by leaving their lawn mowers idle — a practice called No Mow May.

“The idea is that you are leaving the early flowering dandelion and clover to provide some forage for the earliest pollinating insects,” said Mike Goatley, Extension turf specialist and associate professor of crop and soil environmental sciences in Virginia Tech's College of Agriculture and Life Sciences.

“No Mow May has become widespread in the last few years, but May is really too late in Virginia. The clover and dandelion begin flowering in April, and that’s when you’re really getting the value in not mowing,” said Goatley.

It is not just “no-mow” that can help insects, said Shawn Askew, Extension specialist in turfgrass weed science and associate professor in the College of Agriculture and Life Sciences. Mowing less frequently also helps ensure pollinators have a supply of clover and dandelion. Cutting back clover and dandelion plants may even encourage the plants to produce more blooms.

According to Askew, think of it as “less-mow” April. He recommends these practices:

• Reduce mowing instead of not mowing.
• Raise the mower height to increase bloom density.
• Only mow part of the yard each time you mow so that food is always available somewhere on the property.

Are lawns really that important for pollinators?

According to Margaret Couvillon, assistant professor of entomology in Virginia Tech's College of Agriculture and Life Sciences, laws are important for pollinators.

"Because those March and April flowering weeds — the dandelions and clover — are important early sources of food for flower-visiting insects, leaving them uncut in your yard will help feed hungry bees,” said Couvillon.

Recent studies on urban bees suggest that in addition to specialized pollinator gardens, yards with spontaneous lawn flowers also support bees and are important part of the urban pollinator ecosystem. For example, a 2014 study documented 25 pollinator species visiting white clover and 21 species visiting common dandelion.

Leaving grass long also provides necessary habitat for insects.

“The longer you can delay the mow, the better. We know from studies in Europe that delaying that first cut by eight weeks can significantly increase the diversity and abundance of insects in an area in subsequent years because early emerging insects can mate and lay eggs before their habitat is destroyed.”

Be careful when you mow long grass

According to Goatley, avoiding the lawnmower in spring when grass is just starting to grow might have benefits for your turf as well. Leaving the grass a little longer during this time can help the plant direct energy to establishing a strong root system.

When you’re ready to mow again, just be sure not to cut tall grass down to very short all in one mowing, a practice known as “scalping” your lawn. Removing more than one-third of the length of the grass in one mowing is very damaging to the plant.

“If you have let your grass get pretty long, you might be tempted to take it all the way down with your mower on the shortest setting, for example taking the grass from 6 inches down to 2 inches,” said Goatley. “This is exactly the opposite of what you want to do right before the heat of summer begins to stress your lawn.”

Instead, remove height gradually by setting your mower to consecutively lower settings over several days. Follow the rule of thirds: never remove more than one-third of the length at a time.

Goatley cautions Virginians with warm-season lawns — for example, bermudagrass or zoysiagrass — to be especially careful if participating in Less-Mow April.

“Warm season grass can really get away from you,” said Goatley. “If you let your warm season lawn get to 5 or 6 inches, it’s going to be hard to even get the mower through it when you’re ready to mow.”

In addition to avoiding the lawnmower in spring, gardeners can also help pollinators by choosing landscape plants with wildlife benefits. For more information on habitat gardening, check the Virginia Cooperative Extension publication “For the For the Birds, Butterflies, and Hummingbirds: Creating Inviting Habitats.”

“If you choose ornamental plants wisely, you'll be able to attract an abundant, diverse population of insect pollinators," said Couvillon.

For help with your lawn, contact your local Extension Master Gardeners. Extension Master Gardeners are trained volunteer educators who bring the resources of Virginia’s land-grant universities to the people of the commonwealth. Visit the Extension Master Gardener Program website for more information or to become an Extension Master Gardener.