Organic Lawn Care


We all want our properties to look ship-shape and what’s nicer than a pristine green lawn devoid of unsightly weeds? But when we don’t use organic products on our grass, our personal and business landscapes damage the environment, including fresh and marine waterways. 


Excess fertilizer and pesticides run off into our rivers and bays. Synthetic pesticides including weed killers, insecticides, rodenticides and fungicides massacre all living things in their path, including the ‘good bugs,’ giving new meaning to the adage “scorched earth policy.”  And the problems don’t stop there. Routine or unnecessary spraying can cause organisms to become resistant to pesticides, making future infestations more difficult to control. In the last twenty years, due to a variety of reasons, we’ve lost 50% of all songbirds in most of New England. Some pesticides kill birds and beneficial insects, and when this happens, an invitation is extended for even larger infestations later on. 


Watch for thatch, a mat of dead roots and stems accumulating at the surface of the lawn. Quick-release nitrogen fertilizer, poor mowing and water habits, and low microbial activity cause excessive thatch. Excessive thatch blocks growth of healthy grass and provides a medium for insect pests to live.  If the thatch is greater than a half inch, then de-thatch. 


As odd as it sounds, landscapes can become addicted to routine applications of synthetic chemicals. We recommend that you go ‘cold turkey’ and stop using chemicals altogether. Your grass could actually be ‘addicted’ to these chemicals but be patient. The best way for a ‘junkie’ lawn to recover is with two applications (1/4 inch each) of good quality organic compost. This will naturally control thatch by increasing the life in the soil. Potential health threats to humans remain incalculable when homeowners do not use organic lawn products. 


Dangers of Synthetic Lawns

According to Rachel’s Environmental Health Weekly, Non-Hodgkin’s Type Lymphoma – the second fastest-growing cancer in the U.S. – has repeatedly been associated with use of the weed killer 2, 4-D, in studies in the U.S. Canada and Sweden. And for dog owners who use this common weed killer, their companion animals were twice as likely to die of cancer. Childhood cancers linked to pesticides include leukemia, brain cancer, Wilm’s tumor, soft-tissue sarcoma, Ewing’s sarcoma, and cancers of the colorectal and testes, so reports the Environ Health Perspectives. 


At Three Bays Preservation, Inc., we’ve been sounding the alarm on pesticide use for years. Our policy of organic lawn care comes with an online toolkit of lawn care tips. 

Here they are:



  • Prune well. Cut dead and diseased branches from trees and shrubs.
  • Protect the tender bark of trees:  remember, ‘wounds’ are entry points for insects and disease.
  • Speak with your landscaper about the ‘right bugs’ to devour insects likely to infest a healthy tree, such as woolly adelgids, that’s native to Asia but found its way here.
  • Gypsy moths, another Asian-born insect, have been controlled naturally since 1991 by a parasitic fungus.
  • It’s easy to identify egg masses of the eastern tent caterpillar; remove them before they hatch, and nests can be easily taken away by hand.
  • To rid your trees of black vine weevils, obtain healthy nematodes from a reputable source and use them under proper conditions.
  • Use nematodes to ride your trees of grubs.


Lawn Care

  • Renovate your lawn if the thatch layer is thicker than ½ inch.
  • Plant seedlings in the fall.
  • Only plant as much lawn as you need and only where the grass grows well.
  • If you’re seeding a lawn, choose a grass blend compatible with local growing conditions, and high in entophytic fungi, which deters certain surface-feeding insects.
    • Remember, however, that entophytic fungi are toxic to some livestock and should not be used where grasses are foraged.
  • Adding clover to the seed mix will provide your lawn with nitrogen.
  • Remember to seed or overseed only in the fall.

As for the actual mowing of your lawn, keep the mower operating properly and blades sharp. Only mow a third of the grass blade at a time. Remember to leave grass clippings on your lawn to grass will receive about 40% of the nutrients it needs. And it’s okay to cut the grass shorter in the late fall for easier cleanup.


The ideal soil pH for a lawn is 6.3 – 6.8.  Use no more than 125 lbs. of lime per every 1000 square feet every six months. If your soil shows high magnesium levels, use only calcific lime or gypsum. These are high in calcium and low in magnesium. Gypsum improves the texture of soil and adds sulfur and other minerals as well, but will not change soil pH.


Land Care:  Ground Cover, Beds, and Trees & Shrubs


Consider planting an ecosystem, not ‘just’ trees:  plant groupings of several species of trees that are compatible. Here are some more tips:


  • Choose native plants in well-grown and insect-disease resistant varieties.
  • Consider sunlight, soil and water requirements of any species you plant.
  • Grass isn’t suitable for many situations. Grass requires a lot of sun, water and good soil. It’s one of the highest maintenance plants we can grow.
  • Give some thought to groundcovers and what will work for your property; look for the ones that don’t require a lot of maintenance.




  • Test your soil every two to three years, and UMass offers soil analysis for a small fee. 
    • Request the percentage of organic matter in the sample; it should read 3.5% or more.
  • Fertilize with compost, which is the best source of minerals, nutrients and beneficial organisms. It’s sold in many different forms, including liquid.  And you can make your own.
    • Compost can be applied any time, but spring and late summer applications are preferred/
    • Rock minerals should be applied every four years, based on the soil test. These include:  Blackrock phosphate, colloidal phosphate, greensand, sulfate of potash-magnesia, borax, bone meal. More organic fertilizers include these.
  • If you use mixed organic fertilizer, read the list of ingredients in the brochure to determine the real content to ensure there’s no super-phosphate or natural nitrite of soda, which can cause a buildup of salt. 


Water & Mulch


  • Avoid watering too frequently. Vegetable and flowerbeds need an inch or rain per week to flourish.
  • User soaker hoses or a well-timed sprinkler to supplement what nature provides.
  • Once a healthy lawn is established, it will need watering only after seeding or during a drought.
  • An established organic lawn has a more extensive root system, enabling it to find food and water even when it is dry. This enhanced root system enables the lawn to survive a dry spell.  
  • Mulch protects the roots and trunk from damage from mowing.
  • Mulch the entire bed with 1 to 2 inches of leaves, grass clippings, pine needles, buckwheat or cocoa hulls.
  • Around trees and shrubs, mulch to a depth of 2 to 4 inches, but don’t let the mulch touch the bark.


If you use a professional, ask for an organic program with no chemical pesticides. Ask what chemicals are applied. If they apply pesticides, ask if they have a pesticide applicator’s license. Then ask to see it. One last request:  ask them for the MSDS, the Material Safety Data Sheet for every chemical they use.