Homemade Insect Soap
Insect soaps are available in any organic gardening aisle, but gardeners can make a homemade garden spray that’s just as effective for aphids, caterpillars, and mites. Combine three drops of mild dishwashing liquid in one quart of water. An added tablespoon of cooking oil helps the mixture cling to leaves. Spray plants to the point of drenching, but don’t use on blossoms or when temperatures are over 80 degrees F to prevent scorching the plants.
Homemade Tobacco Bug Spray
Everyone is familiar with the negative health effects of cigarettes, but the nicotine in tobacco is poisonous to all kinds of insects as well. Gather enough cigarette butts to harvest ¼ cup of tobacco leaves. Place these in a sock, and soak them in a quart of water overnight. Avoid using this homemade insect spray on eggplant and tomato plants, as tobacco can harbor the mosaic virus.
Hot Pepper Bug Repellent
Even for gardeners without a penchant for spicy foods, it’s worth adding a row of hot chili pepper plants to the garden for their bug repelling effects. Place a handful of dried hot peppers in the food processor, seeds and all, and grind to dust. Take care not to get the dust on the skin or eyes. Sprinkle around garden plants to repel ants and onion maggots.
Rubbing Alcohol Bug Spray
Rubbing alcohol quickly desiccates the bodies of soft sucking pests like aphids, mealy bugs, and thrips. However, it can also damage plant tissues, so gardeners should use alcohol sparingly in the garden. Dab a cotton swab soaked with rubbing alcohol directly on the pests, taking care to avoid the plant. Plants with waxy leaves may tolerate a dilute alcohol spray of one-cup alcohol mixed with a quart of water.
Bug Juice Spray
Gardeners may be repulsed yet fascinated to learn that one can make a natural bug spray out of the pests themselves. No one is exactly sure why pests are their own worst enemies when applied to plants, but researchers speculate the presence of an anti-cannibalism mechanism or a chemical that inhibits insect feeding. Gather enough of the offending pests to fill at least a teaspoon, and pulverize them with the back of a spoon. Place the mashed bugs in cheesecloth, and soak in two cups of water overnight. For best results, use the bug juice within three days.
Source: Day, R. (1993, September). “Bug Juice Hits the Spot.” Rural Delivery, p. 18.
Watch out for tobacco mosaic virus, don’t smoke near or handle some plants after touching tobacco. Solamances (spuds, toms, peppers) squash, courgette, cucumber and dope are all effected.