Frequently asked questions

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Which nematode do I need?

It depends on your pest. Scanmask treats the widest range of pests and is our pick for treating several pests at once or preventing them. Ecomask is best for fleas and hot, dry climates. Heteromask is best for white grubs. Pick your pest on Which nematode do I need? and we'll point you to the right one.

How much do I need?

We use one rate for every product and every pest: 25,000 nematodes per square foot. So 10 million nematodes treat 400 square feet. Each product page shows how much area each size treats, and Which nematode do I need? does the math for your pest and area. We don't inflate our rates: applying the right amount is what makes nematodes work.

When should I apply them?

You can apply nematodes any time the soil isn't frozen, though they may not become active until the soil warms up. The best timing depends on the pest's life cycle; for white grubs, late summer to early fall is usually best. Apply in the late afternoon or evening. See When to apply.

How do I apply them?

Water the area first, mix the nematodes with cold water, and apply in the evening with the Nema-Jet Sprayer, a hose-end sprayer, a pump sprayer, or a watering can. Then water again to wash them into the soil. See How to apply for step-by-step directions.

How do I store them?

In the refrigerator, ideally between 35 and 50°F (a normal refrigerator), until you use them. Never freeze them, and use them by the date marked on the package. Shelf life depends on the product and size. See Shipping and arrival.

Are they safe for kids, pets, bees, and earthworms?

Yes. Our nematodes attack insect pests only. They don't harm people, pets, plants, or beneficial creatures like bees, earthworms, ladybugs, and praying mantises. The EPA has exempted beneficial nematodes from the registration required for chemical pesticides. The material they're packed in isn't meant to be eaten, so keep packages away from children. More on the About page.

Can I use them with fertilizers or pesticides?

Usually, yes. Nematodes work alongside many common herbicides, insecticides, fungicides, and fertilizers. Some chemicals should be applied one or two weeks before or after the nematodes. Check the active ingredient on your product's label against the compatibility list on our How to apply page.

How fast do they work, and how long do they last?

Once a nematode enters a pest, the insect usually dies within a day or two. About 3 to 4 weeks later, a new generation of nematodes comes out of it to hunt more pests. One application typically lasts about a year, and in many cases longer. Rather than treating again on a set schedule, keep an eye out for the pests coming back, and treat again when you see them.

Can I use them indoors?

Nematodes live in soil, so they work in potting soil, greenhouses, and garden beds, but not on carpets or furniture. For fleas, treat the yard, and vacuum often and wash pet bedding indoors until the problem clears up. See Fleas and Fungus gnats.

When will my order ship?

We ship Monday through Wednesday, so your nematodes never sit in a warehouse over a weekend. Orders placed by 2 PM Eastern on those days ship the same day, and later orders ship on the next ship day, so orders placed after 2 PM Wednesday or Thursday through Sunday ship the following Monday. We skip ship days right before UPS holidays. Every order is delivered within 2 business days of when it ships. Shipping is free to the 48 contiguous states and Washington, DC.

See Shipping and arrival for the details.

The cold pack was thawed when my box arrived. Are my nematodes OK?

Yes. A thawed cold pack is normal and doesn't affect your nematodes. Our shipping is tested to keep them alive for 92+ hours even at 100°F, and your order arrives well within that. Nematodes are soil organisms and handle this range of temperatures naturally. Put them in the refrigerator right away if you're not applying them immediately, and use them by the date marked on the package.

What if my order is lost, damaged, or late?

If your order is lost, damaged, or delayed more than 3 days, we'll replace it. Contact us and let us know what happened. See Refunds and guarantee.

Where else can I buy BioLogic nematodes?

The best place is right here: order directly from us on this website, and your nematodes come straight from the producer. See all products.