The Arvada Parks and Open Space division takes great pride in maintaining both our irrigated and non-irrigated lands. Safety, aesthetics, and adherence to the City’s park maintenance standards are our top priorities. The Parks and Open Space division maintains more than 2,500 acres of non-irrigated land throughout the City. Each growing season, our parks staff mows approximately 1,350 acres of open space areas bordered by hundreds of private properties. In an effort to maintain the health and aesthetics of the City’s natural areas and trail corridors, the City of Arvada has adopted and is following a Low-mow/Let it Grow practice for open space and natural areas within the city. This practice is similar to policies that other municipalities have enacted and is recognized as a best practice in open space maintenance.
Low-Mow/Let it Grow Areas
The low-mow/let it grow areas are important places of special use for Arvada’s wildlife and conservation interests that are different from neighborhood parks and athletic fields in use and maintenance. These open space and natural areas are non-irrigated lands that receive water only from rain and snow and would exist as-is in their natural condition if left undisturbed by humans. They include designated native grass landscapes, designated natural areas, wildlife resting/habitat and trail corridors along with undeveloped city owned open space properties.
Low-mow/let it grow benefits
- Native grasses are able to regenerate naturally by propagating their own seed.
- Native grasses support wildlife by providing food and cover.
- Many urban wildlife species, like coyotes or raccoons, are less likely to be pushed into neighborhoods as unmowed native grasslands provide preferential food and shelter. This may reduce occurrences of human/pet & wildlife conflicts.
- Native grasses help promote the return of other native plants and animals, including threatened and endangered species.This supports a balanced ecosystem by increasing biodiversity.
- Pollinators, such as native bumble bees, benefit from these policies which provide habitat and places for them to rest and have a meal. Colorado has 946 native bee species, some of which rely on undisturbed grasslands to nest.
- Healthy native grasslands filter pollutants from stormwater run-off.
- Local air quality is improved through reduced fuel emissions from mowers.
- When allowed to grow to a natural height, native grasses reduce non-native weed growth.
- There are reduced chemical impacts on our environment due to the elimination of fertilizer use and fewer weeds.
- Healthy, tall, non-dormant native grasses act as a “water reservoir” and provide a level of defense against a stronger-intensity wildfire. A low mow approach to open space maintenance does not increase fire risk.
Negative impacts of frequent/untimely mowing
- Mowing too frequently can result in high levels of insect mortality, including many native bee and pollinator species that local gardeners and agricultural groups rely on.
- Frequent mowing can disperse local wildlife into neighboring residential areas as they seek food and shelter.
- Untimely mowing can reduce native seed dispersal, which increases the likelihood of noxious and invasive weeds out-competing native plant species.
Mowing schedule
The Arvada Parks and Open Space Division mows open space in the spring after the first big flush of growth. Once native grasses start coming up (including milkweed, which is excellent for pollinating butterflies) the team stops mowing until some time around the first hard frost in the fall. This is when the desirable native plants go to seed. We then mow in order to spread the native seeds and continue to grow populations of desirable plants in the open space areas. Our large open space areas are only mowed once a year (if at all) to allow native grasses to thrive.
What does this approach look like in practice?
Courtesy cut: this is the section next to fencing, approximately 5 - 8 inches in height (up to three times yearly when possible).
No mow area: this is the section between the courtesy cut and trail cut. These areas will be left to grow.
Trail cut: this is the section between the no mow area and the trail pathway, approximately 5 - 8 inches in height.
