No Mow May is a conservation initiative started by the UK-based organization, Plantlife. Over the last couple of years, this effort has gained a lot of attention in the United States. The primary message of No Mow May is to leave your lawn unmown for the month of May, creating habitat and food sources for early season pollinators.
No Mow May Can Potentially Support Pollinators
Spring is an important time for many pollinators. Many bees and other pollinators have limited food sources early in the season, especially in urban and suburban environments. 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. One frequently-cited study showed that unmown yards in the city have a fivefold increase in the number of bees present (Note: this study has since been retracted from the academic journal because of problematic data collection and research techniques).
Providing food and habitat for pollinators while eliminating the work of mowing the lawn sounds like a no-brainer! But there are a few things to keep in mind before you lock the mower away for the entire month of May.
It Will Take a Lot of Effort to Get the Lawn Back Under Control
In much of the Midwest, including Iowa, the grass will grow at least a foot in the month of May. The grass will likely outgrow the flowering plants and once tall enough will smother any plants underneath. Most mowers are not equipped to cut grass that tall once June arrives. Ideally, you only remove one-third of the total leaf blade in a single mowing. Whether you use a mower or a string trimmer, taking grass that is 12+ inches tall down to the typical lawn height of 2.25 to 3 inches will cause stress or death of the grass because you are removing so much leaf material at once. Additionally, there will be a lot of grass clippings to chop up or remove. Grass clippings left piled on the lawn will smother and kill the plants underneath leaving bare or open spots in the lawn.
You Will Encourage the Growth of More Weedy and Invasive Plants
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. Additionally, most weeds common to lawns are not native. When allowed to grow unchecked, these weedy plants can become problems in other areas of the landscape and potentially natural ecosystems such as nearby woodlands or prairies.
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. This includes woody plants like mulberry, Siberian elm, or honeysuckle as well as other weedy forbs like velvetleaf, leafy spurge, and garlic mustard. Thankfully, most woody species would not have time to produce flowers and set seed before mowing resumes. However, they would make reclaiming the lawn more difficult. Some of the weedy forbs could produce flowers and seeds in that relatively short period furthering the spread of these unwanted invasive plants.
Lawns are Not Natural Spaces
In Iowa, nearly all lawns are comprised of non-native grasses and most of them have some (or many) weeds that are also non-native plants. They are highly managed spaces that require many inputs of water, nutrients, and time spent mowing. If you stop managing the lawn, it will not revert to a more natural space. Instead, it will be a collection of non-native plants allowed to grow unchecked. The lawn will always need some sort of management because it is a completely constructed and created landscape. Simply ignoring or halting the maintenance of the lawn is not a responsible way to manage these non-native plants.
Most Municipalities Will Issue Citations for Unkempt Lawns
Most cities and municipalities have some type of weed ordinance. These ordinances vary from place to place. They are typically created to reduce noxious weeds, manage pest problems like mice or rats, prevent dangerous property conditions, minimize allergens, and maintain the aesthetics and property values in the community. They outline the height and sometimes the types of plants that can be grown in the lawn and those properties that don’t abide by the ordinance face fines or mowing fees. The way most ordinances in cities, counties, or HOAs are written would not allow for grass to remain unmown for an entire month.
Working with local officials to modify or temporarily suspend weed ordinance regulations would help you avoid fines. Keeping a mowed edge or border can also help as it defines the space and shows that the tall lawn is intentional and not due to neglect. Since most weed ordinances are enforced primarily by reporting from neighbors, engaging and educating neighbors on what you are doing, or putting up a sign showing that the space is for pollinators, is beneficial.
Providing additional food for pollinators early in the season is just one of many steps you can take to support pollinators. With the many pros and cons to No Mow May it can be difficult to decide what you can do to both promote and support bees and other pollinators while still being a responsible manager of your landscape. There are some things you can do with your lawn that can achieve both.
Participate in Mow Less May
It is typical to mow once a week during the month of May in Iowa. Some small preliminary studies show that mowing every two weeks can still significantly increase bee population size. So instead of No Mow May, participate in Mow Less May. Mowing less frequently can support the cause and avoid many of the drawbacks. Most flowering plants in lawns, like dandelion and clover, flower even with mowing. By extending the time between mowings from every 7 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 such as citations, undesirable weeds, and stress to the lawn.
Mowing less frequently will require you to set the mower height high to avoid removing too much leaf material at once. The good news is that mowing grass at a taller height promotes a healthier lawn. Mowing at a height of 3.5 inches (or a little higher for the month of May) 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.
Create a Well-Designed Pollinator Garden
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. When located in areas that connect to other nearby pollinator-friendly gardens or natural areas, these managed spaces not only look beautiful but provide food sources all season without promoting weeds or risking citations.
More information on creating pollinator gardens can be found in this Article: Creating a Garden Bed as a Turgrass Alternative.
Consider Eliminating the Lawn
Lawns are highly managed spaces that require many inputs. Simply not managing it for one month does not help pollinators all year and does not greatly reduce your maintenance inputs, especially when you consider the added effort it takes to get your lawn back after a month of not mowing. Consider eliminating the lawn altogether and replacing it with plants or garden spaces that don’t require frequent maintenance and support native insects and wildlife. Replacing turf with perennials, groundcovers, shrubs, and trees can reduce water consumption, pesticides, and fertilizers while increasing soil organic matter, building soil quality, and helping to retain and infiltrate stormwater. Remember, you don’t have to remove the entire lawn all at once this spring. Phase in the transition from lawn to garden space. Even just eliminating a portion of the turf in your landscape can help you see significant growth in the number of pollinators visiting your yard.
More information about lawn alternatives can be found in this article: Lawn Alternatives to Turfgrass