Hb Nematodes
Grubs in the roots are hidden and stressful. Hb goes down to find them for you.
The deep hunter: Hb tunnels down through warm, moist soil after beetle grubs and weevil larvae in the root zone.
- Ships live, when readyUsually within 7 days, rarely 10. Mon–Thu, 2-day or overnight.
- Live arrival coveredReport concerns within 72 hours
- Free shippingWhen bugs and plant care come to $30
Handmade by Linda, for the plants you're protecting
2 inch · $20Buying for a group or a business? · Wholesale
01 · The problem
Are Hb nematodes right for your grubs?
Signs it's grubs
- Brown, thinning patches of lawn that spread through late summer.
- Turf that lifts like a carpet because the roots underneath have been eaten.
- Japanese beetles on your roses last summer: their grubs are in the lawn now.
Seeing these? Good catch. The sooner you start, the smaller the job.
Illustration · not to scale
Illustration · not to scale- You receive
- Millions of live nematodes on a moist carrier, mixed into water at home
- Main target
- Beetle grubs and root weevil larvae in lawns and beds
- Best conditions
- Warm soil, 65–90°F, kept moist for two weeks
- Not for
- Fungus gnats in pots (Sf), fleas or caterpillars (Sc), anything on leaves
Works on
- Japanese beetle grubs
- June beetle and chafer grubs
- Black vine and strawberry root weevils
- Rootworms
Not the answer for
- Fungus gnats in houseplants
- Fleas and caterpillars at the surface
- Anything on the foliage
02 · Meet the beneficial
Heterorhabditis bacteriophora
Illustration · not to scaleIts partner glows. That's a keep-out sign.
Hb carries bacteria that make their own light, the only bacteria on land known to do it. A grub with Hb inside can glow faintly in the dark.
One worm can start a family
A single Hb worm inside a grub grows up able to fertilize its own eggs, so one alone can start a whole new population.
The glow is a keep-out sign
Scavengers took fewer glowing grubs than ordinary ones, but only in the dark, where the glow shows. The light guards the worms' nursery.
Brick red on purpose
A grub with Hb inside turns brick red, likely a warning to daytime scavengers like birds: this one tastes bad, leave it.
03 · How it works
Microscopic hunters in the soil
Illustration · not to scaleMix and water in
Stir them into water and apply with a watering can or sprayer.
Illustration · not to scaleThey find the larvae
Nematodes move through moist soil to reach the pests.
Illustration · not to scaleMoist soil keeps them going
Follow the watering steps below after you apply.
Illustration · not to scaleRepeat on schedule
A follow-up application catches the next wave.
Nematodes are a watering, not a release: you won't see them, so you judge them by the lawn.
Hb nematode temperature and storage
Illustration · not to scale65–90°F soilThe warm-season nematode. Works best above 60°F, so it's a summer job, not an early spring one.
Illustration · not to scaleFridge, about 3 weeksKeep the pack at 38–42°F until you mix, never the freezer. Hb keeps the shortest of the three, so use it promptly.
Illustration · not to scaleMoist for two weeksThey swim the water film down through the soil. Sandy and loamy soils suit them; compacted clay needs aerating.
Illustration · not to scaleSpray waitsNeem and horticultural oil: once dry. Insecticidal soap: one day. Sulfur: 21 days.
04 · Not your conditions?
Choose one of these instead
Not quite your situation? No problem. If your space or your pest is different, one of these fits better.
Fungus gnats in potsSf NematodesGnat larvae sit in the top inch, Sf's layer, and it costs less
View →
Fleas, cutworms or webwormsSc NematodesSc waits at the surface for pests on the move
View →
Grubs plus surface pests, or not sureTriple Blend Nematodes for Broad-Spectrum Soil Pest ControlThree species cover every soil depth in one watering
View →05 · The plan
How to apply Hb nematodes
No experience needed. Here's all it takes.
Illustration · not to scalePick the moment
Late summer (August or September) when young grubs hatch. Warm soil only, above 60°F.
Illustration · not to scaleLooks like almost nothing
That small, clumpy pack holds millions of nematodes, far too small to see. Mixed into water it just looks cloudy. Judge them by the lawn.
Illustration · not to scaleMow and water
Mow short and water the lawn well first, so the nematodes have an open, moist path down.
Illustration · not to scaleMix in dechlorinated water
Stir the carrier into dechlorinated water and break up any clumps. Apply within a few hours.
Illustration · not to scaleSpray, filter out
Hose-end sprayer on free flow or 1:15, filter removed, or a watering can. Shake as you go; they settle.
Illustration · not to scaleWater them down
Out of direct sun, then water again to wash them into the root zone. Keep the soil moist for two weeks.
06 · What happens next
What to expect
Living things work at their own pace. Here's what normal looks like.
Illustration · not to scaleQuiet work underground
Grubs are infected within a day or two. Nothing shows above ground; the damage simply stops spreading.
The lawn comes back
Turf stops thinning and plants stop wilting for no visible reason.
Brick-red proof
Curious? Dig up a grub a few days later. An infected one turns a distinct brick red.
Next year's beetles
Grubs in the lawn are next summer's Japanese beetles, so fewer grubs now means fewer beetles later.
07 · Reviews
What growers say
Before you order
All your questions, answered
Something else? Toby's in the chat, bottom right, and happy to help.
When does it ship, and how does it arrive?
Millions of live nematodes on a moist carrier, in a pack that weighs almost nothing. Straight into the fridge when it lands. Bugs and plant care ship free from $30; $15 under that. Pots and grow lights ship by ground, free from $75.
What if something's wrong when it arrives?
Our Live Delivery Guarantee covers it. Email info@fgmnnursery.com with your order number: within 72 hours of delivery for insects and springtails, or within 7 days for mites and nematodes. Full terms are on the Live Delivery Guarantee page.
My lawn is already brown. Is it too late?
Not for the grass that's still green: Hb goes after the grubs before they move into it or come back next year. Patches that lift like a carpet have lost their roots, so reseed those.
How deep do they go?
Hb is a cruiser: it moves down through loose soil to find grubs, deeper than the surface-waiting Sc.
Can I use weed-and-feed products?
Hold off on high-nitrogen chemical fertilizers and herbicides for a few days before and after. Strong salts dry the nematodes out.
Why is the carrier clumpy?
The carrier soaks up moisture in transit, which is normal. Break it up well in the bucket before it goes in the sprayer; the nematodes wash out into the water.
Ready when you are
Hb Nematodes
You've got this. And if you get stuck, we're one email away at info@fgmnnursery.com.