The label is the law. Rates and restrictions below are taken from the product labels listed under Sources. Your product's own label governs; read it before you mix or apply. Mixing calculator · Disclaimer
- Active ingredient
- Trichoderma harzianum Rifai strain T-22
- Chemical class
- Fungal biofungicide in FRAC Group BM02. FRAC now lists strain T-22 under the name Trichoderma afroharzianum.[2][1]
- Mode of action
- FRAC Group BM02: Biologicals with multiple modes of action: microbial strains (competition, mycoparasitism, antibiosis)[2]
- Signal word
- RootShield Home and Garden Biological Fungicide (T-22 WP, residential sub-label): Caution[1]
Plants to skip
The label says not to apply it to sugarcane, bok choy (pechay), rice, mushrooms, kiwi, barley, oats, lemon, apple or chickpea, and not to aquatic plants.[1]
The commercial directions also warn against tank mixing it with imazalil, propiconazole, tebuconazole or triflumizole fungicides.[1]
Where it is used
It is preventive. The live spores must go on before disease starts, so treat at seeding or transplanting rather than after roots rot.[1]
It only becomes active above 50°F and does nothing while soil stays cold.[1]
Use it as a drench only. The label says it is not for spraying on foliage or fruit.[1]
Store it in the original container in the refrigerator, and don't keep it above 75°F for long.[1]
Products and registrations
| Product | Registrant | EPA Reg. No. | Active % | Formulation | Signal word |
|---|---|---|---|---|---|
| RootShield Home and Garden Biological Fungicide (T-22 WP, residential sub-label)[1] | BioWorks, Inc. | 68539-4 | 1.15% | wettable powder of live fungal spores | Caution |
Label rates
| Product | Use | Pests | Rate |
|---|---|---|---|
| RootShield Home and Garden Biological Fungicide (T-22 WP, residential sub-label) | Home vegetable, flower and ornamental seeds, transplants, beds and pots | Root diseases, including Pythium, Phytophthora, Rhizoctonia and Fusarium | 1–3 tbsp product per gallon of water[1] Give each transplant or 4 to 8 inch pot 1/2 to 1 cup of mix. Beds take 1 gallon per 25 square feet, and seeds 1 gallon per 25 feet of furrow before covering. |
Safety and environmental hazards
People
Signal word CAUTION: harmful if absorbed through skin, inhaled or swallowed, and causes moderate eye irritation. Avoid breathing the dust and wash with soap and water after handling.[1]
Pets
The hazard statement applies to people and domestic animals. Store the product refrigerated where children and pets can't get to it.[1]
Bees and pollinators
The label has no bee or pollinator statement; it is applied to seeds, roots and soil, not sprayed on foliage.[1]
Fish and water
Keep it out of storm drains, ditches, gutters and surface water, and apply in calm weather when no rain is expected for 24 hours.[1]
Common questions
- How much RootShield per gallon?
- One to three tablespoons per gallon of water for every home and garden use.[1]
- Can I spray RootShield on leaves for powdery mildew?
- No. The home label limits it to seeds, plant roots and soil and rules out foliar or fruit sprays.[1]
- Is it organic?
- The home and garden sub-label carries the statement For Use in Organic Gardening.[1]
Sources
- U.S. EPA Pesticide Product Label System, “T-22 WP Biological Fungicide (RootShield Home and Garden) master label label, EPA Reg. No. 68539-4 (EPA-stamped, Sept. 28, 2022).” www3.epa.gov/pesticides/chem_search/ppls/068539-00004-20220928.pdf (accessed 2026-10-06)
- Fungicide Resistance Action Committee, “FRAC Code List 2025.” www.frac.info/media/ljsi3qrv/frac-code-list-2025.pdf (accessed 2026-10-06)