Hb Nematodes

Hb is a specialist predator for slow-moving, deep-soil larvae that chew on roots.

• Primary Targets: Japanese Beetle Grubs, European Chafer Grubs, Masked Chafers, and June Beetles.
• Secondary Targets: Black Vine Weevils, Strawberry Root Weevils, and Cucumber Beetles.
• Ant Control: Hb is one of the few nematodes effective against ants, as they can attack the Queen deep in the nest, forcing the colony to move or die out.
• The "Red" Sign: When Hb kills a host, the pest often turns a distinct reddish-brown color due to the specific bacteria they release.

Hb is a warm-season nematode and requires specific conditions to hunt effectively.

• Temperature: They are heat-loving and perform best when soil temperatures are above 54°F. They are less effective in early spring cold snaps compared to Sf nematodes.
• Moisture: Critical. They use water films to swim deep into the soil. Dry soil stops them in their tracks.
• Soil Type: They work well in sandy and loamy soils where they can move easily, but may struggle in extremely compacted clay without aeration.

Not sure if you need pure Hb or a mix? Here is how to decide.

• Choose Pure Hb (The Grub Killer): If your primary problem is your lawn dying in patches due to White Grubs or Japanese Beetles. This is the concentrated solution for deep-root eaters.
• Choose Sf (The Gnat Killer): If you are treating indoor plants for Fungus Gnats. Hb is generally "overkill" and too deep-diving for shallow gnat larvae.
• Choose Triple Blend (The All-Rounder): If you have Grubs plus surface pests like Fleas or Ticks. The blend gives you coverage at all depths.
• Choose Sc (The Ambusher): If you are targeting mobile surface pests like Fleas or Caterpillars. Hb is too slow to catch these fast movers.

Timing is everything with Hb nematodes, as you must target the grubs when they are active.

• Preventative Rate: Apply 1 package (e.g., 5 Million) per 250 sq. ft. once in late Summer (August/September) when young grubs hatch.
• Curative Rate: For active grub damage (yellow patches, loose turf), double the density (e.g., 5 Million per 125 sq. ft.) and apply every 2 weeks for 2–3 rounds.
• Prep: Mow your lawn short and water thoroughly before application to help the nematodes reach the soil.
• Mix: Dissolve the carrier into water and stir well.
• Apply: Use a hose-end sprayer (set to "free flow" or 1:15 ratio) or a watering can. Remove any mesh filters to prevent clogging.
• Post-Care: Water immediately after application to wash the nematodes off the grass blades and down into the root zone. Keep the lawn moist for at least 7 days.

Packaging: Shipped in a dormant state in a carrier powder or gel.

Viability: The paste/powder will look inactive until mixed with water.

Storage: Refrigerate immediately. Hb is more temperature-sensitive than other species. Store at 38-42°F for up to 3 weeks. Do not freeze.

The ideal window is Late Summer to Early Fall (August–September). This is when the beetle eggs hatch into young, vulnerable grubs. Treating in Spring is harder because the grubs are large, tough, and about to pupate.

Not immediately. Hb kills the larvae (grubs) in the ground, preventing them from turning into beetles next year. It is a long-term population control strategy, not a quick spray for adult beetles on leaves.

If the grass is already dead (pulls up like a carpet), the roots are gone. However, applying Hb now will kill the grubs before they spread to the green parts of your lawn or return next year.

Avoid using high-nitrogen chemical fertilizers or herbicides for 72 hours before and after application. High chemical salts can dehydrate the nematodes.

Hb nematodes are capable of digging down 6–8 inches or more in loose soil to find prey, which is significantly deeper than other species like Sc or Sf.

The carrier material can absorb moisture during transit. This is normal. Just break it up vigorously in the water bucket before pouring it into your sprayer. The clumps are just carrier; the nematodes will dissolve out into the water.