By Bob Dailey
"It may be doubted that there are many other animals which have played so important a part in the history of the world as have these lowly organized creatures."
-Charles Darwin, The Formation of Vegetable Mould through the Action of Worms.
The best method to judge the health of the soil beneath a lawn is to discover how many earthworms are present.
Earthworms can restore the hard pan of compacted dirt so prevalent in lawns. Their castings are rich in nutrients: nitrogen, phosphorus and potassium, three major elements necessary for plant growth and photosynthesis. Castings also contain magnesium, carbon, calcium – all very important plant nutrients. In just one year, a thousand earthworms (and their descendants) can transform one ton of organic waste into high-yield fertilizer.
Some important ways earthworms help transform the soil:
- They tunnel through the soil, aerating it as they go.
- Their channels also allow water to enter and penetrate the soil more quickly.
- Grass roots can also grow better in soil loosened by earthworms, resulting in a deeper root system and healthier lawns.
- Earthworms neutralize the soil, either lowering the alkalinity or raising the acidity. Turf grass likes soil nearer to the middle between acidic and alkaline.
- Earthworms consume organic material (like thatch).
- Worms can compost four times quicker than a well-managed composting bin.
- A large population of earthworms helps control pests. Many soil-borne diseases are reduced significantly when earthworms are present.
How to attract earthworms:
- Spread 3/4 inch of organic material twice a year onto the lawn (mid-October and mid-April are the best times).
- Use a mulching lawnmower and let the clippings drop back onto the lawn. Earthworms will bring much of this material below ground to eat and digest.
- Don’t use pesticides or use them in extreme moderation. Choose organic pesticides if necessary. Pesticides are indiscriminate and kill earthworms and other beneficial organisms.
- Don’t use man-made chemical fertilizers. “Chemical” fertilizers contain sulfuric and hydrochloric acids which are deadly to earthworms. Few worms exist in soils treated with chemicals. Use organic fertilizers instead.
There is no need to add earthworms to your lawn. There are earthworms in the area and will be attracted to chemical-free, organic ally rich soil. And the turf grass will be well on its way to being healthy and green.