How to Control Common Lawn Disease and Insect Problems With Organic Methods

Too much rain, too little watering, hot dry or humid weather - all these can stress your lawn and promote fungal disease and insect damage. Your lawn problems will be worse, if your soil is compacted, drains poorly or you fertilize too much or too little. White grubs, cinch bugs, billbug grubs, cutworms, sod webworms and mole crickets can wreck your lawn. Most of these insects can be controlled without toxic chemicals. Toxic chemicals may harm pets and children and will kill also beneficial insects that feed on your bad bugs. To remedy any lawn problem, you first have to identify the cause of damaged turf. Here are the steps you need to take to identify the cause of those dead or dying patches of grass and then treat your lawn with organic methods.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• coffee tin (or similar container) with cut away top and bottom
• soapy water
• milky spore powder or beneficial nematodes
• cornmeal
• tools for dethatching and aerating (manual or rented machine)

1. Find out if your lawn damage is due to fungal disease or insects. If after prolonged periods of hot humid weather, you notice round brown patches of grass, you probably have the fungal disease "Brown Patch". Irregular areas of dead or weak grass could be due to other fungal diseases. But one fungal disease, Fusarium Leaf Blight and crown Rot, is not caused by wet weather. It is caused by hot (75-90 degrees Fahrenheit) temperatures and dry conditions.
   
   To determine if brown or dead patches are due to insect damage, get a coffee tin or similar container and remove the top and bottom. Insert the can partially into your damaged area and add soapy water (one teaspoon liquid detergent in one quart of water). If you have cinch bugs, sod webworms or mole crickets, they will float to the top. Cinch bugs are small black bugs with a light triangular patch on their back, which is formed by folded white wings. Sod webworms look like small caterpillars with shiny dark heads and light brown bodies studded with dark spots. Mole crickets are 1.5 inches long and look like the common crickets, but have a larger head and short wide legs. These insects take hold of your lawn during hot dry weather.

2. Treat fungal disease. Most fungal diseases are caused by too much moisture (rain or watering) and too much nitrogen-rich fertilizer. Let the lawn dry out completely between waterings and avoid watering in the evening. Improve drainage by aerating the soil. To renew dead patches, remove the dead sod, add soil and overseed patches with disease-resistant varieties, when possible. Generally, if you dethatch or aerate your lawn to reduce compaction, you can avoid fungal disease. To reduce disease due to Fusarium, dethatch and increase waterings.

3. Get rid of cinch bugs, sod webworms and mole crickets. Reduce cinch bug populations by extensive watering. Treat your lawn with beneficial nematodes to diminish sod webworms and mole crickets.

4. Get rid of white grubs and billbug grubs. Dead areas in your lawn could be due to white grubs or billbug grubs. The "C"-shaped white or gray grubs are the larvae of Japanese, June or May beetles. Billbug larvae are small legless grubs with an orange head. If you have a severe infestation of grubs, you can test for it by tugging on your sod. If the turf comes up like a piece of carpet, you have grub damage and you will be able to see the grubs underneath the sod. Milky spore or beneficial nematodes are the best organic treatment for white grub infestations. Billbug larvae can be controlled by dethatching your lawn and in case of heavy infestations, treating with insecticidal soap or Neem oil-containing sprays.

5. Get rid of cutworms. Cutworms can be eliminated by applying cornmeal.

Tips & Warnings

• A lawn that is healthy with good drainage, sufficiently fertile soil and no compaction and is watered during dry spells and not mowed too low, will be largely resistant to serious disease and insect damage.
• If you have trouble identifying an insect, take a specimen to your local garden extension center.
• Not all dead patches of grass are due to disease or insect damage, a dog's urine will easily kill your turf.