Tomato Leaf Insecticide: Folk Remedy vs. Scientific Reality and Disease Risks

Q: Does steeping cut tomato leaves in water overnight and spraying on plants work as organic pest control?

I've heard gardeners do this but no results reported. Scientists extracted solanine and tomatine from tomatoes as insecticides. They kill insects but less effectively than nicotine (also in tomato leaves, but more concentrated in tobacco). Side note: cauliflower, eggplant, potato also contain nicotine. In Cuba I saw farmers soaking discarded tobacco stems overnight, straining, spraying on eggplants—zero flea beetle damage, which we dread in Georgia.

Many garden plants contain insecticidal chemicals: yaupon holly (caffeine), peppers (capsaicin), catnip (pulegone), lemons (limonene), chrysanthemum (pyrethrin), cloves (eugenol). Try tomato leaf spray but remember liquid can spread disease to tomatoes, peppers, eggplants, potatoes.

The Nicotine Content of Common Vegetables