A sulfur burner, more accurately a sulfur vaporiser, is an electric heater with a small dish that warms elemental sulfur until it sublimes and drifts through a room, settling as a fine film on leaves. That film suppresses powdery mildew and some mites. Elemental sulfur is a widely used, long-established fungicide and acaricide active ingredient.
In practice
Growers run vaporisers in veg and mother rooms, typically during the dark period and with nobody present. Safety and timing points:
- If the sulfur overheats or ignites, it forms sulfur dioxide, a toxic, choking gas, so the unit must stay within its designed temperature and away from anything flammable.
- Sulfur dust and vapour irritate eyes and lungs; keep people and pets out.
- Sulfur and oil sprays near each other in time can scorch leaves.
- Vaporising in flower taints aroma and leaves deposits on buds; stop well before flower.
Whether sulfur use is permitted on cannabis, and on what terms, depends on product registration and local rules. Check what is registered for cannabis locally and follow the label.
Don't confuse with
- Wettable sulfur sprays: the same active, applied in water.
- Lime sulfur: calcium polysulfide, a harsher product.
- Sulfur as a nutrient: sulfate in feed, an essential plant element.
Sulfur (S) is a secondary nutrient taken up as sulfate, used in the amino acids cysteine and methionine; deficiency yellows new growth fairly evenly.A fungal disease, on cannabis caused mainly by Golovinomyces ambrosiae, that grows as white powdery patches on leaves and buds and thrives in moderate humidity.Tetranychus urticae, the commonest cannabis mite indoors: a 0.5 mm sap-feeder that stipples leaves pale and spins webbing, breeding fastest in hot, dry rooms.Sulfate (SO4 2-) is the form in which plants take up sulfur, delivered mainly by magnesium sulfate and potassium sulfate in mineral feeds.Aculops cannabicola, a microscopic eriophyid mite specific to cannabis that causes upward leaf curl, bronzing and dull, greasy-looking trichomes.A refined petroleum or plant oil sprayed to smother soft-bodied pests and eggs and suppress powdery mildew on contact; used only on foliage, never on flowers.The minimum time, set on a pesticide label, that must pass between the last application and harvest so residues fall to permitted levels.Contact products act only where the spray touches the pest; systemic products are absorbed and move inside the plant, which raises residue concerns in cannabis.
