If fungus gnats, thrips, or codling moths are your main concern, the HB + SF Beneficial Nematode Mix is built for exactly that. This two-species soil treatment combines Heterorhabditis bacteriophora (HB) and Steinernema feltiae (SF) in one easy-dissolve powder, pairing two nematode species with overlapping but distinct pest targets for more thorough coverage than either alone.
SF is the go-to species for fungus gnats, thrips pupae, and shore flies (pests that spend part of their life cycle in the top layer of soil). HB reaches deeper, targeting grubs, cucumber beetles, and other larvae that burrow further down. Together, they address pest pressure across multiple soil zones in a single application. Safe around people, pets, and edible plants. No chemicals, no residue, no protective equipment required. Compatible with IPM programs.
What Pests Do Hb + Sc Nematodes Control?
How It Works
These microscopic soil organisms seek out the larval, grub, nymph, and pupal stages of common soil pests. Moving through moisture in the soil, they locate and eliminate young pests before they develop into adults, effectively breaking the cycle without harsh chemicals.
When to Apply
Active infestation: Apply weekly to monthly and adjust based on pest infestation level.
Preventative: Seasonal applications in fall and spring are highly effective at stopping early pest stages before they mature. A little prevention goes a long way.
Application Instructions
Applying beneficial nematodes is as straightforward as watering your garden. Activate the powder by mixing with water, then apply using a watering can, pump sprayer, or hose-end sprayer.
General Guidelines
- Apply indoors at any time; apply outdoors in the morning, evening, or on a cloudy day
- Avoid direct sunlight; nematodes are sensitive to UV exposure
- Do not exceed 72 PSI application pressure
- Nozzle diameter must be 0.8mm or larger
- Use room temperature water (59 - 69°F); allow powder to dissolve for 15 minutes before applying
- Nematodes are not a chemical, so the solution concentration can be adjusted freely based on infestation level and coverage area
Watering Can & Pump Sprayer
Prepare
- Moisten soil before application to improve habitat
- Keep soil moist for two weeks after application and avoid runoff
Activate
- Mix nematodes with 1- 5 gallons of water (59 - 69°F) to cover the target area
- Dilute to create the volume needed for full coverage
Apply
- Apply evenly to the target area, nematodes will move through the soil, so complete inch-by-inch coverage isn't necessary
- Use within 6 hours of activation
After Application
- Water the treated area immediately
- Maintain soil moisture for two weeks and avoid runoff
- Keep soil temperature between 44 - 86°F
Hose-End Sprayer
Remove any filter screen before use. Allow powder to dissolve in room temperature water for 15 minutes before attaching to hose. Walk slowly and evenly across the target area for consistent coverage.
Instructions:
- Add nematodes and water to the reservoir
- Attach the hose-end sprayer to your water source and turn on the water
- Twist the knob at the top of the sprayer to ON
- Apply evenly across the target area
Reservoir amounts by package size:
Package Size Instructions
50 million Divide into thirds. Fill reservoir to 15-gallon mark. Mix ⅓ and spray until empty. Repeat 3× until fully applied.
25 million Divide in half. Fill reservoir to 15-gallon mark. Mix ½ and spray until empty. Repeat twice until fully applied.
10 million Add all nematodes to reservoir. Fill to 10-gallon mark. Apply to target area.
5 million Add all nematodes to reservoir. Fill to 5-gallon mark. Apply to target area.
Other Hose-End Sprayers
If your sprayer has a screen filter, remove it before use. Application measurements vary by sprayer type, refer to the application charts in the product photos.
Instructions:
- Add all nematodes to the reservoir
- Fill water to the 32 oz mark
- Set the dial to the appropriate level
- Apply to the target area
Dial settings by package size and infestation level:
| Package Size | Preventative/Light | Moderate/Heavy |
| 50 Million | 4 tsp | 5 oz |
| 25 Million | 1.5 oz | 8 oz |
| 10 Million | 4 oz | 8 oz |
| 5 Million | 4 oz | 8oz |
Application Rates
Infestation Level Coverage
| Preventative / Light | 5 Million per 1,250 sq. ft |
| Moderate / Heavy | 5 Million per 250 sq. ft. |
Storage
- Unopened: refrigerate and use within 30 days
- After activation: use within 1 hour
- Activated solution: use within 6 hours maximum
Growing Conditions
Soil temperature should be consistently above 53°F at time of application.
Pro Tips
- Nematodes are sensitive to UV light. Always apply outdoors during low-light conditions. Early morning, evening, or overcast days work best.
- Moisten soil before application and maintain moisture for two weeks afterward. Optimal soil temperature is 44–86°F. In high-heat conditions (above 86°F), irrigate with at least 0.1 inches of water before and after application.
- Accurate pest identification improves results. Monitor your plants closely and apply early; addressing pest populations before they're established is far more effective.
- Avoid applying alongside broad-spectrum or systemic insecticides, which are toxic to nematodes. Pesticides, wetting agents, and spreader-stickers can also reduce effectiveness. Check chemical compatibility before combining treatments.
Chemical Compatibility
Some pesticides and fertilizers can harm nematodes and reduce their effectiveness as biological control agents. Before applying any additional treatments, check this Beneficial Nematode Chemical Compatibility Guide.
Safe, Natural Pest Control
- 100% natural — no synthetic chemicals
- Safe around people and pets
- Safe for edible plants and food gardens
- Compatible with IPM (Integrated Pest Management) programs
- Leaves no residue
- No protective equipment required