Dear Mrs. Greengenes,

I heard that homeowners use many times more chemicals on their lawn than farmers do! I don’t have a lot of time for yard care, but I enjoy a healthy looking lawn. How can I reduce time and fertilizers? --Loves Grasses

Dear Loves Grasses,

You are absolutely correct! In fact, according to Greg Horn in Living Green, “The average suburban lawn uses six times the hazardous chemicals than conventional farming” (28). But don’t fret. Let's talk about ways to make your lawn greener and lawn care easier. You can mow and water less and save time and money.

The simplest step is to set your mower blades as high as they will go. Two and a half or three inches is good. Longer grass is stronger because the roots go deeper into the soil, and the longer grass blade absorbs more of the sun’s energy. Stronger grass can beat out weeds for sunlight, so you don't need to apply chemicals to kill the weeds. Also, sharp mower blades make grass more resistant to disease.

If you do use chemicals, look for the set of three numbers on the bag or box. The middle number stands for phosphorus. It should be zero. Minnesota soil has adequate phosphorus. Adding more causes a runoff that grows algae in our lakes. Algae consume oxygen. With less oxygen in the water, fish are fewer and smaller. In Minnesota, what happens to our lawns affects our water.

Instead of chemicals, try two cheap and convenient weed killers. Pour boiling water or vinegar over the offending weeds. You may need to apply either of these treatments more than once to kill your weeds. However, both are effective and inexpensive.

Then stop watering your lawn. Yes, that’s right. It sounds strange, but it will develop a better lawn. Wait until the lawn shows signs of drying out, then water the lawn at night or early in the morning. Water deeply - at least one inch of water. (You can move your rain gauge right under the sprinkler to measure accurately.)

The deeper watering will foster longer, deeper roots. Deeper roots will support healthier, more resilient grass. However, please note in July and August, most typical grasses in Minnesota lawns go dormant and will not need more than a half inch of rain every three weeks or so.

You can get rid of the bagger mower. Leaving grass clippings on the lawn returns the nutrients to your grass. If you mow regularly and the clippings are well spread out, you shouldn't see any thatch buildup. A summer’s clippings are roughly equal to one application of fertilizer.

If you are seeding your lawn, talk to the U of M extension agent or your local nursery about the type of grass that’s best for your soil and yard conditions. Some grasses are much more shade and cool weather tolerant. Others can handle full sun and drying winds easily. You can make wise choices for a healthy lawn by using these resources.

If you cannot get a decent lawn or are tired of mowing, convert part of your lawn into a rain garden. Rain gardens are depressions in the earth near solid surfaces such as blacktopped driveways or rooftops. Shrubs, wildflowers and tall grasses filter runoff by removing contaminants before they reach bodies of water.

Farmers and families in homes that slope down to lakes use filter strips of tall grasses for the same purpose. Because you never mow them, rain gardens and filter strips reduce soil erosion, improve water quality, and provide food and homes for wildlife.

The next step is to get the pH of your soil tested. The fee is about twenty dollars. If results report the soil pH is lower than 6.0, you will need to add lime. If the test says that your soil is above pH 7.0, then you need to add gardener's sulfur. These products are usually available at local feed and seed stores or greenhouses.

Check your top soil. That is the black stuff, not sand, not clay. We have a wide variation of soil types in Minnesota, so it's best to dig a small hole and see if you have at least four inches of proper top soil. If you don't have enough, then it doesn't matter how hard you try to grow grass. You need topsoil to hold nutrients for growing grass.

Bare patches in your lawn on slopes or in higher spots, especially in new construction areas, may be a sign of not enough top soil for a healthy lawn. Talk to a landscaper or lawn care specialist about topdressing in this case.

Resources

“Conservation Choices,” U.S. Department of Agriculture Soil Conservation Service, St. Paul, MN.

Dakota County, MN. A Quick Reference Guide to Earth-Friendly Home Landscaping, www.co.dakota.mn.us

Horn, Greg. Living Green: A Practical Guide to Simple Sustainability, CA, 2006. www.wellbuilding.com

MPCA Brainerd Office, 7678 College Road, Suite 105, Baxter, MN 56425, 800-657-3864, http://www.pca.state.mn.us/

http://soiltest.coafes.umn.edu/submitti/htm (follow instructions for soil submission).