Ecomask Topdressing

For fleas, chinch bugs, mole crickets, and a general or preventative treatment, you can apply Ecomask anytime the soil is not frozen. Other pests have a best window; for example, cutworms are treated from March to July, before planting. The treatment calendar lists the timing for each pest.

The nematodes in Ecomask are active in soil at about 68°F and above. (That's the soil temperature, which can differ from the air temperature.) You can apply them in cooler soil, but they may not become active until the soil warms up.

Apply at dusk if you can, or in the late afternoon or evening. Sunlight and heat harm nematodes.

As a topdressing:

1. Add 1 cup of water to the nematode container and let it sit for 30 minutes at room temperature.
2. In a bucket, mix 4 gallons of peat moss, vermiculite, sandy humus, or potting soil with ½ gallon of water.
3. Add the contents of the container to the mixture, then rinse the container with ½ cup of water and add that too.
4. Mix thoroughly so the nematodes are spread evenly through the moist mixture.
5. Water the area to be treated.
6. Spread the mixture by hand, concentrating on the affected areas. The 25 million size treats about 1,000 sq ft. Use all of the mixture within 24 hours of mixing.
7. Water again afterward to wash the mixture off the leaves.

For fleas, focus on shaded areas of the lawn, around shrubs, under porches, around buildings, and anywhere your pets spend time. See How to apply for more methods and tips.

Put the container in the refrigerator right away, and use it before the date on the package. Never put it in the freezer. The cold packs in the box don't need to still be cold when it arrives. See Shipping and arrival.

The nematodes in Ecomask occur naturally in soil and haven't been modified in any way. They are harmless to people, pets, and plants, and the US Environmental Protection Agency (EPA) has exempted them from the registration required for chemical pesticides. The carrier they come in isn't meant to be eaten and may upset the stomach, so keep the container away from children.

Ecomask works alongside many common herbicides, insecticides, fungicides, and other biological controls, but some need to be applied a week or two apart; see the chemical compatibility list on our How to apply page.

They contain the same nematode. The topdressing comes in a granular carrier that you mix with peat moss, vermiculite, or potting soil and spread by hand, which protects the nematodes from heat, sunlight, and drying out. It also keeps longer in the fridge. For spraying, we recommend Ecomask Spray.

No. Nematodes live in soil, so they can't be used indoors. Treat the lawn and yard where flea larvae live, and vacuum often and wash pet bedding until the fleas are gone.

Yes. Beneficial nematodes don't harm people, pets, plants, or beneficial creatures like bees, earthworms, and ladybugs. The EPA exempts them from pesticide registration.