Organic Control of Spider Mites on Tomatoes

Keeping spider mite infestations from organic tomato plants is fairly simple.

Pesticide control of spider mites is impossible with chemical organic-certified controllers. According to the British Columbia Greenhouse Growers Association, tomato plants respond slowest to organic chemical pesticide treatments. There are however ways to organically control spider mites without harmful chemicals.

Neem Oil Spray

The worldwide organic specialists at Infonet-biovision.org (IBV) recommend using oil formations of neem products to protect plants from spider mites. Neem oil is a natural derivative of the neem plant and is safe for use as a spray. The entire plant--including the underside of leaves--must obtain a coating of neem oil to protect against spider mites.

Soap Spray

The IBV suggests using soap sprays to halt spider mite infestations. Soap sprays may harm plants, and it is wise to test several leaves waiting two to four days for noticeable results to ensure plant damage will not occur. Using a pure soap will help ensure plant health is not endangered in the use of soap sprays. Early morning or late afternoon sprays work best, and the entire plant must be sprayed.

Pyrethrum Extract Spray

IBV proposes the use of pyrethrum sprays--a flowing plant extract--for spider mite trouble. Pyrethrum extracts work best on early infestation outbreaks but will kill beneficial insects as well. If the extract is directly applied to spider mite outbreak areas, then the beneficial insects are likely left unharmed.

Flour Sprays

The IBV reports that, "flour mixed in water is said to be very effective against aphids and spider mites." Flour sprays are applied in the early morning; as the sun rises, the residue hardens and insects trapped inside shrivel and die. The entire plant must be covered. The coating of flour will fall off leaves once completely dry and not harm the ability of the plant to photosynthesize.

Glue Sprays

The IBV states that glue sprays are also excellent spider mite killers. Organic glues manufactured from plant starches will not harm plants when mixed with water and applied as a foliar spray. The thin film that hardens will trap and kill insects but leave a permeable membrane plants can breathe through. The entire plant is coated when glue spraying.

References

• BC Greenhouse Growers Association: Screening Organic Miticides for Spider Mite Control
• Infonet-Biovision (IBV): Spider Mites