The grower's answer to russet mites and powdery mildew. Microthiol Disperss is a micronized wettable sulfur, 80% sulfur, milled down to particles of 9 microns or less. That fine particle size is the whole point: more particles per ounce means better coverage on the leaf, and coverage is what kills mites. It's OMRI Listed and carries both Federal and California registrations as a fungicide and miticide on over 50 crops.
Why our customers buy it
Two reasons, over and over. First, as a preventative clone dip. Russet mites are microscopic and they hitchhike into a clean room on incoming cuttings before you ever see damage. A sulfur dip and quarantine on every clone that comes through your door is one of the cheapest insurance policies in growing. Second, as the tool people turn to when they actually have a russet or broad mite problem and need to knock it down. When growers say sulfur is their best friend against russets, this is what they mean.
The BuildASoil Way is usually to avoid taking in any clones and to just start over if you have russet mites but some growers swear by using this as a preventative when clone trading.
How growers use it for russet and broad mites
Sulfur works in veg, not in flower. It kills mites on contact and disrupts their cycle, but it takes repeat coverage to catch newly hatched mites, and it can leave a smell on buds if used too close to harvest.
The common approach:
Coverage is everything. Russets hide in curled new growth, at stem junctures, and in the newest tips. Spray to full wetness, tops and undersides of every leaf. A spot you miss is a spot that repopulates.
Repeat on a tight schedule. Most growers spray every 3 to 7 days and plan on at least three applications, because sulfur hits mites but not always their eggs. Consistency is what finishes the job.
Spray with lights off, or in the early morning or late evening, to avoid leaf burn.
Scout as you go. A handheld scope (14x or better) lets you confirm you're actually winning. Don't assume, look.
The clone dip
Dip incoming cuttings, then quarantine them away from your main room for a couple of weeks before you introduce them. Scope the new growth before it graduates into your clean space. This single habit stops the most common way russets ever get into a garden.
The one rule you cannot break: no oils. Never mix sulfur with horticultural or essential oils, and don't apply it within 14 days before or after any oil-based spray. Sulfur plus oil burns plants, badly. Keep them well separated on the calendar. This is the single most common way growers hurt their plants with sulfur, so plan your rotation around it.
Product Details
Microthiol Disperss is a dry flowable sulfur in a granular form. It's dust-free, dissolves cleanly without foaming, mixes in water with no special agitation, and stays in suspension for spraying by hand sprayer, backpack, or larger equipment. Its spreader-sticker qualities help it adhere to leaves and resist wash-off.
- 80% micronized sulfur, particles 9 microns or less
- OMRI Listed for organic production
- Federal and California registered fungicide and miticide
- Controls powdery mildew and multiple mite species
- Dust-free, mixes easily, excellent leaf coverage
- 30 lb bag
Label rate: Follow the product label for your crop and situation. The registered foliar rate is 2 tablespoons per gallon of water. Do not apply within 14 days of any oil product, and spray with lights off. Always read and follow the label.
Download the SDS sheet
