Book Excerpt: As Insect Control Season Begins Consider Natural Approaches
With the weed control season winding down in most areas of the country, the advertising from the lawn chemical industry will begin focusing on insect control. Everything from ants to aphids, to cinchbugs and grubs will begin to surface in our lawns and gardens. The urge will be to kill them dead with whatever product folks can purchase the fastest.
Before you rush out to purchase something from the category of pesticides known as insecticides, take a moment to read this excerpt from The Organic Lawn Care Manual:
THE NATURAL CONTROLS
Natural approaches to insect and disease on lawns can be broken into roughly four categories: 1) cultural controls that focus on grass selection and soil improvements; 2) physical controls that employ manual labor and barrier type structures; 3) biological controls that encourage a “beneficial” organism to overtake the pest organism; and 4) botanical controls such as sprays and dusts, which should be the last line of defense even in a natural lawn care system. All of these should be part of your RILE approach [Relax, Identify, Listen, Eradicate], which may sound a lot like what some texts refer to as Integrated Pest Management. The reason I don’t defer to all aspects of IPM is that this approach allows for use of toxic synthetic chemicals as a last resort; in natural lawn care, these chemicals have no place.
Cultural — How you water, mow, apply fertilizers and soil amendments are all part of a cultural approach to pest control. If you apply too much water or it rains too often, brown patch may develop. If you apply too much nitrogen to force out top growth, brown patch could also be a symptom. As you read through the descriptions of various pests and diseases (elsewhere in the book), you’ll see that altering the culture of your lawn — raising the mower blade, raking to remove leaves, debris and thatch, limiting or adding water, adding organic matter etc. — should be the first line of defense. Planting disease-resistant cultivars or hybrids of grasses is also a cultural control. As detailed in Chapter 3, many of the newest grass varieties will naturally fight off any problems, or they contain fungi known as endophytes that strengthen a grass plant’s resolve. At least 80 percent of the time, these types of changes will lead to a permanent resolution of the pest or disease problem.
Physical — This mean you have to take action. Believe it or not, if you own a shop-vac and you see chinchbugs, leaf-hoppers or the moths of sod web worm hopping about on your lawn, you can simply vacuum up the pests, which will then be trapped in the canister. It works like a charm. You can also simply dig up an area impacted by dollar spot, brown patch and dog spot. Replace the impacted soil and overseed with a new grass seed, or patch it with a small piece of sod, and the problem may not return. Keep a canister with pre-mixed seed and soil in your potting shed or garage; if you see a disease problem developing on your lawn, dig out the problem, pour in the seed/soil mixture and water it in. It’s not unlike what golfers do on the course each time they take up a divot off the tee. One final physical change worth noting is altering the amount of sunlight an area of the lawn receives. If part of a lawn constantly bakes in the sun, you may create shade by planting a carefully sited tree. Far more often, though, the problem will be too much shade and you’ll want to remove all or part of trees and shrubs or fences so the lawn receives more light.
Biological — Controlling pests with their natural enemies is the basis of biological pest control. When you add compost to your soil to encourage diversity of soil life, you are practicing this form of control in it most primitive form. If you think of soil in terms of having a bloodstream of red blood cells and white blood cells, the organic material you add to your lawn helps make sure the balance of good vs. evil organisms stays in balance. Natural lawns encourage beneficial critters we can see — birds, ladybugs, big-eyed bugs and minute pirate bugs — and all the ones we can’t, like mycorrhizae and bacteria.
Sometimes we take action by adding biological controls into the soil. For white grubs, one of the best controls comes from applying beneficial nematodes into the soil. The microscopic creatures move through the soil in search of the grubs, eating them from inside out when they come upon their target. The good news is the nematodes don’t do any damage to non-target pests. Bt, Bacillus thuringiensis, is another common biological control. First discovered in 1911 in Thuringia, Germany, Bt combats moths and butterflies in their caterpillar stage. Caterpillars that eat Bt, a natural bacteria, die when the Bt spores are activated in the insects’ stomachs. Bt comes in several formulations; 100 million pounds are used each year in the U.S., but you need to be sure you’re using the correct Bt for your target pest.
Botanical — Occasionally, even when we think we have the soil perfect and the grass seems to be otherwise healthy, the pests will still appear in highly frustrating or treatable numbers. If you have determined that all cultural, physical and biological controls have been exhausted, you may decide to turn to a botanical — meaning plant based — control. With synthetic chemicals falling out of favor or being pulled off the shelves due to safety issues, a huge market has developed for sprays, soaps, traps, oils and other products designed to kill or repel pests. It should be stressed right up front that just because this new generation of products is plant based, that does not always mean it is entirely safe for humans, pets or the environment. Pyrethrin, for example, is a plant-based nerve poison used to control various checking and sucking insects; it is moderately harmful to humans if not used carefully and judiciously. Other common botanical lawn pest controls include: boric acid; neem; citrus oils; compost teas; copper; diatomaceous earth; sulfur; garlic and many other herbs.