54 April 9, 2008

In my last column, I told you that I would discuss some of the organic ways to control weeds and insects in your lawn.

Let’s start the discussion with an organic way to control crabgrass. For many years, there was not an effective way to organically control crabgrass. In the last 8 years or so, many people have found out about using corn gluten. Corn gluten prevents the crabgrass seed from getting their roots established in the soil. It can also work to control other lawn weeds that may grow from seed. The only drawback to using corn gluten is that it will also prevent grass seed from getting established in your lawn. However, unlike the conventional chemical crabgrass control method where you need to wait about 14 weeks before you can re-seed, corn gluten allows you to re-seed in about 6 weeks. To control crabgrass, the corn gluten is applied before the crabgrass is set to germinate. This would be roughly before the forsythia drop their flowers. The soil temperature that causes the forsythia to drop flowers is about the same temperature that causes the crabgrass seed to sprout.

Controlling broadleaf weeds in your lawn is a bit more difficult. Most of the organic weed killers that work on broadleaf weeds are non selective. This means that the weed killer will kill any leaf that it comes in contact with when it is applied to your lawn. This would include your grass. This means that when you apply broadleaf weed controls that are organic, you must be careful not to spray it on your grass. The organic broadleaf weed controls also, for the most part, only kill the leafy part of the weed. The weed can re-grow from the root system. It usually takes repeated applications of an organic broadleaf weed killer to finally kill off the weed.

There can also be times where you want to organically control insects in your lawn. Neem oil is a good alternative to control chewing and sucking insects that attack your lawn. Neem can also be used to control Japanese Beetle grubs. The spray is mixed with water and applied to your lawn and then watered into the lawn so that it comes in contact with the grubs.
There is also a long term control that kills beetle grubs. The product is called Milky Spore. The Milky Spore is applied to the soil and then watered into the soil. As the beetle grubs come into contact with the spores, they become infected and soon die from the bacterial disease. As the grub dies, they release more spores into the soil, spreading the spores over a larger and larger area. It does take a few years for the spores to spread over the entire lawn. Once the spores are in the soil, you can have control for up to 20 years.

While we are on the subject of organic lawn weed and insect control, let’s take a few sentences to talk about organic lawn fertilizer. Over the past few years, I have seen an increased interest among customers for using organic fertilizers on their lawns. Along with organically feeding the lawn, the breakdown of the organic fertilizer also releases organic material into the soil. This helps to build up the organic matter in your lawn. The increase in organic matter in the lawn means that your soil will hold moisture better and the actual nutrients will stay in the soil longer. A win- win situation for those folks who don’t have a lot of organic matter in their soil. The increase in organic matter is not an overnight thing. It will take years of applying organic fertilizers to make a big difference in the organic composition of the soil. But hey, you have to start some time.

Well, that’s all for this week. I’ll talk to you again next week.