Benefits & Impacts of Lawns
A drive through most any Maplewood Neighborhood will confirm that, like most of America, we love lawn. And why not? Lawns are great places to play and to relax, they withstand trampling and compaction, they protect the soil and provide aesthetic benefits. But lawns are very needy and maintaining them can have negative impacts on the environment.
Lawn Maintenance Impacts on the Environment
- Fertilizer: Lawns need lots of nutrients and most receive synthetic fertilizer. Improper fertilization can lead to nitrates leaching into groundwater and phosphorus runoff into streams and lakes.
- Mowing: Mowing requires fossil fuels and creates air pollution. In the early 1990s, the Environmental Protection Agency (EPA) reported that a lawnmower emitted as much hydrocarbon in one hour as a typical auto driven 50 miles (EPA, National Vehicle and Fuel Emissions Lab)! Since then the EPA has adopted stricter regulations on emissions from lawn equipment and newer mowers create much less pollution.
- Pesticides: The use of weed killers, insecticides, and fungicides on home lawns has increased dramatically in the last 2 decades. Many of these contain ingredients that are harmful to the environment as well as to human and pet health.
- Water: Most lawns rely on the sprinkler. Using gallons of water on grass contributes to depletion of groundwater supplies. This is a serious problem in some regions of the U.S, and is becoming a concern in our region.
Low-Input Lawn Care Approach
Low-input lawn care is an approach that requires less input of water, fertilizer, pesticides, and care. This is not a wildflower meadow - it's a lawn composed of Kentucky bluegrass and fescues. If cared for properly it can be a beautiful, healthy lawn. A low-input lawn is based on 2 key principles:
- The varieties of turf grass used are more tolerant of drought and low nutrient levels.
- The grass is allowed to follow its natural growth cycle. In our area this means letting the lawn go "dormant" in July. Dormant doesn't mean dead! It just means growth is slowed - which means less water and nutrients are required.
Transitioning to a Low-Input Approach
In transitioning to a low-input approach, you need to consider is what type of grass you have. Lawns of common Kentucky bluegrass and/or fine-leaved fescues work well with a low-input approach; fancy improved bluegrasses do not.
If your lawn is 30 to 35 years old, it probably has common Kentucky bluegrass and fescues and you can begin a low-input regime. If your lawn was sodded, or was seeded with a premium or elite mix, it probably contains improved varieties that require more maintenance.
You will need to overseed with low-maintenance varieties before switching to a low-input approach. In addition, if your lawn is very weedy or unhealthy it may require some renovation (weeding, aerating, and overseeding) before you begin a low-input regime.
Low-Input Lawn Care
Here are 6 easy steps to a beautiful low-input lawn:
- Mow higher. Mow your lawn 3 inches or higher. But never mow off more than 1/3 of the blade or the grass will be stressed. Keeping the lawn higher helps promote deeper rooting, which gives the lawn a better chance of getting water and nutrients from the soil.
- Leave clippings. Leave grass clippings on the lawn. These will decay and become a source of nutrients. A mulching mower is helpful but not necessary.
- Water less. Low-input lawns do not require watering, except possibly during a severe drought.
- Fertilize less often. Most low-input lawns are fertilized once - in fall. A very low-maintenance lawn may get by with no fertilizer, especially if the soil has high organic matter. Minnesota Extension Service recommends using a 4-0-2 or 3-0-2 fertilizer for lawns. These 3 numbers indicate the percentage of Nitrogen, Phosphorus and Potassium (N-P-K).
- Spot-treat weeds and pests. The best defense against weeds, disease, and insects is a healthy lawn. A healthy lawn can tolerate low levels of pests. That said, there may come a time when pests are out of control. In this situation the 1st step is to verify what the pest is. Minnesota Extension Service can help you diagnose the problem and suggest solutions.
- Aerate and overseed when necessary. If your lawn is thin, patchy, or weedy you may need to aerate and overseed. Aerating helps reduce soil compaction. Overseeding simply means adding seed to an existing lawn. These tasks are best done in fall but could be done in spring.
A low-input lawn doesn't have to be an all-or-nothing proposition. Mowing high (3 inches) and letting clipping fall into the lawn are simple first steps which will promote a healthier lawn that requires less water and fertilizer.