Collection: Foliar Sprays

Foliar sprays for hydroponic pest control deliver insecticides, fungicides, and plant protection treatments directly to leaf surfaces — the fastest and most targeted way to manage spider mites, thrips, aphids, whitefly, and powdery mildew in an indoor grow room. Unlike root-zone treatments, foliar application reaches pests where they live and feed, and works quickly enough to halt an infestation before it spreads through your crop.

Why foliar spraying matters in hydroponics

In a sealed grow room or grow tent, pest populations can double rapidly — spider mites in particular can complete a full lifecycle in under two weeks at typical indoor temperatures. Foliar sprays interrupt that cycle by targeting insects and eggs on contact, without waiting for root-zone uptake. Weekly preventative spraying from early vegetative growth is far more effective than reactive treatment once a full infestation is established. Even a light application of an organic insecticide or plant barrier treatment each week can significantly reduce pest pressure throughout the entire grow.

What's in this collection

• Pyrethrum-based insecticides — fast-acting natural insecticides derived from chrysanthemum flowers, effective against a broad spectrum of soft-bodied insects on contact (Kendon Insect Destroyer Natural Pyrethrum Concentrate)
• Plant barrier treatments — oil-based or mineral-based coatings that form a physical barrier on leaf surfaces, preventing insects from feeding and breeding (MR 24/7 Plant Barrier Treatment)
• Broad-spectrum organic sprays — concentrated organic formulations that control mites, eggs, powdery mildew, and botrytis in one application (PureCrop1, Green Cleaner)
• Systemic fungicides — absorbed through leaf tissue to protect against fungal disease including powdery mildew and root rot (Rid-A-Rot Systemic Fungicide)
• 360° spray bottles — food-safe, chemical-resistant spray applicators designed for foliar work in confined grow spaces (Wurth 360° 500ml and 1L pump spray bottles)

How to choose the right foliar spray

Match the product to the pest

Spider mites, thrips, and aphids respond well to pyrethrum concentrates and oil-based organic sprays like PureCrop1 or Green Cleaner, which kill insects and eggs on contact. For powdery mildew or botrytis (grey mould), a systemic fungicide or broad-spectrum organic spray is more appropriate. MR 24/7 works best as a preventative barrier treatment applied before pest pressure is visible, rather than as a knockdown once an infestation is active.

If you're not sure what pest you're dealing with, start with a broad-spectrum organic option like PureCrop1 — it covers mites, soft-bodied insects, and common fungal pathogens in a single product.

Preventative vs. active treatment protocols

For prevention, apply a diluted organic spray or plant barrier treatment once per week from week one of vegetative growth, alternating between products to reduce the risk of resistance. For an active infestation, increase to every five to seven days for two to three applications, ensuring complete coverage of both the upper and lower leaf surfaces — the underside of leaves is where spider mites and thrips eggs are most concentrated.

When to stop spraying

Most foliar sprays should be discontinued two to three weeks before harvest to avoid residue on finished produce. Always follow the manufacturer's directions for withholding periods. Pyrethrum breaks down quickly in UV light and is generally considered a low-residue option, but the label recommendation is always the safest guide.

A-Grade Hydroponics carries foliar pest control products suited to both hobby home growers and larger production grows, all with Australian stock and expert advice available by phone or live chat. Browse the full range above or contact our Cheltenham, VIC team if you need help identifying the right product for your pest problem.