Triple Blend Nematodes for Broad-Spectrum Soil Pest Control

Three nematode species in one package — Steinernema feltiae, Steinernema carpocapsae and Heterorhabditis bacteriophora — so the surface, the shallow layer and the deep root zone are covered at once. It is the one to buy when you have more than one soil pest, or when something is eating roots and you cannot say what. You do not have to diagnose it correctly to treat it.

What each is doing down there: Sf works the shallow layer on fungus gnat larvae, thrips pupae and fruit fly larvae. Sc ambushes at the surface for fleas, caterpillars, cutworms, sod webworms and crane flies. Hb cruises deep for beetle grubs, chafers and weevil larvae. The two Steinernema species enter a host through its natural openings; Hb cuts straight through the cuticle. Either way, the bacteria they release kill the host within a day or two.

All of it goes down in one watering. No spray, no residue, no re-entry interval, and nothing to keep children, pets or pollinators away from — you mix them into dechlorinated water, water them in and leave them to it. They reach the whole soil column rather than the surface a drench wets, nothing they kill can develop resistance to being parasitised, and they are harmless to earthworms and bees.

The honest caveat is temperature. The three do not share a range, so the blend is active across roughly 50–90°F but never with all three working at once — the cool end is Sf's, the warm end is Hb's. And the soil must be moist at application and stay moist for about two weeks, the water dechlorinated, applied in the evening because direct sun kills them.

Best for: Mixed soil pests, or an unidentified root problem — gnats and grubs at the same time.
How many: Sizes go by pot count. Against an active infestation, repeat every two weeks for two or three rounds.
Arrives as: Live infective juveniles on a moist carrier. Refrigerate at 38–42°F and use within two to four weeks. They are heavy and sink fast, so stir or shake every few minutes while you apply.
Safe around: People, pets, plants and earthworms.
Not for: A single confirmed pest, where the specialist is cheaper and more concentrated. Fungus gnats alone indoors are Sf's job. And nothing on the foliage.