How to Get Rid of Whiteflies

mediumGardening30 minutes8 steps

Safety Warnings

Extreme caution required: Hydrocyanic acid gas/potassium cyanide is highly toxic and should only be used by professionals in enclosed spaces.

Sprayer — Hand-held or pump sprayer for emulsion application

Kerosene emulsion — Insecticidal spray(As needed)

Whale-oil soap — Insecticidal soap spray(As needed)

Marigolds — Companion plant(Multiple)

Calendula — Companion plant(Multiple)

Nasturtiums — Trap crop plant(Multiple)

Sweet Alyssum — Beneficial insect attractant(Multiple)

Potassium Cyanide — Fumigant (for greenhouses only)(1 oz per 1000 cu. ft.)

Plant Marigolds or Calendula near susceptible plants to repel whiteflies.

Tip: These act as natural deterrents while attracting other beneficial insects.

Incorporate Nasturtiums into the garden to serve as trap crops.

Tip: This draws whiteflies away from your primary plants.

Plant Sweet Alyssum to attract parasitic wasps and hoverflies.

Tip: These beneficial insects provide natural predatory control of whitefly populations.

Inspect the undersides of leaves for small greenish, scale-like nymphs.

Tip: Early detection of nymphs prevents adult fly outbreaks.

Manually pick off and destroy infested leaves as soon as they are discovered.

Tip: This prevents the insects from spreading to healthy foliage.

Spray affected plants with kerosene emulsion or whale-oil soap.

Tip: Ensure thorough coverage of the leaf undersides.

For severe infestations in cucumbers or tomatoes within a greenhouse, fumigate overnight using potassium cyanide.

Tip: Use 1 oz of potassium cyanide for every 1000 cu. ft. of space for 30-45 minutes.

Turn under any infested plant material after harvest to eliminate remaining pests.

Tip: This prevents pests from overwintering in the soil.

Synthesized from 4 verified sources:

Gutenberg: Manual of GardeningView →

Gutenberg: Home Vegetable GardeningView →

Wind River Greens Plant DatabaseView →

Cornell ExtensionView →