The Bay Gardener by Dr. Frank Gouin

How to Grow a Fine Lawn Without Fertilizer

Test and lime, test and lime, test and lime

A homeowner whose property adjoins the Bay asked me about applying fertilizer to her lawn. Would it be possible to grow a good lawn without any fertilizer? she wondered. Yes, I told her, but don’t neglect adding limestone.

Both acid rain and decaying organic matter cause soils to become more acid. With acidity, the availability of nutrients decreases as does the breakdown of organic matter and the release of more nutrients. If you are going to grow a lawn without applying any commercial fertilizers or compost, you must optimize soil conditions so that the microorganisms can function at their maximum capacity.

A healthy lawn can be grown without using any commercial fertilizer or compost. However, the pH of the soil must be maintained at a level near 6.5. This means having your soil tested and adding the amount and proper kind of liming materials. I highly recommend the A&L Eastern Agricultural Laboratory (www.al-labs-eastern.com) in Richmond, Virginia.

Liming materials are very safe to use near bodies of water. They have a low level of solubility; depending on the type used, they will contain primarily calcium, a component of seawater. Some liming materials such as dolomitic limestone may also contain magnesium. Magnesium is very important in plant growth because it is the center of the chlorophyll molecule. A deficiency in soil magnesium will result in poor growth.

If your intent is to grow a healthy lawn without commercial fertilizers or compost, you will need to lime your lawn at least every three years. Each new application should be preceded by good soil analysis. Only after you have had your soil tested two to three times over a nine-year period can you determine the frequency, kind and amount of liming materials you will need.

For instance in the 19 years we have lived at Upakrik Farm, I have concluded after five soil tests over 15 years that I need to apply 50 pounds of dolomitic limestone every three years to maintain the pH of my soil near 6.5. Since my lawn adjoins Rockhold Creek, I too am concerned about polluting the Bay and have stopped applying commercial fertilizers.

I have a healthy lawn, but I am noticing an invasion of clover. Since clover can fix its own nitrogen from the air, it most likely will become dominant. The beauty of clover is that it is extremely drought resistant. I don’t have to worry about clover stains on clothing, either, since I seldom have young children rolling on the lawn.

What to Do about Moles

Q All of a sudden my lawn is infested with moles tunneling under the grass. Is there a solution?

–Francis Boucher, Shady Side

A You apparently have a heavy infestation of grubs in your lawn to have attracted such a rapid infestation of moles. Next spring, apply milky spore on your lawn. Follow the instructions on the package to the letter. It will give your lawn lifetime protection.