While yesterday I waxed on how the hot weather has been great for our lovely garden plants this year I am also reminded that the season seems equally advantageous for all the critters that attack them. But with kids afoot, water from wells and the desire to do less harm to our environment I long ago gave up on the modern chemical means of horticultural warfare. Instead, like other organic gardeners, I have to be creative in order to keep plants healthy and secure. We employ bugs (ladybugs) to eat other bugs, flowers (marigold) to keep our flowers safe, strong smells (cinnamon, urine) to scare away predators, and any natural-based substance we find that may help.
Soap is often my first line of garden defense. When sprayed directly on soft-bodied insects–like aphids or those tiny, annoying white flies–insecticidal soap will smother them and they eventually die. It is less useful on beetles and other hard-shelled insects, although, for instance in the case of squash bugs, it may work to kill off their eggs or young and therefore control the population. It is very easy to make your own insecticidal soaps as long as you follow four simple rules:
1- Use only pure glycerine soaps made by combining vegetable or animal oils and fats with an alkali. Do not use a foaming detergent (including shampoo) made up of Sodium laureth sulfate.
2-Use in a concentration of 2%; practically that is ca. 1-2 TB per quart water.
3-Some foliage may be sensitive to soap (especially azaleas, begonia, bleeding heart, and ferns). If in doubt, spray a ‘test’ area of foliage and wait to see if there is a reaction.
4-Always spray in a cool time of day, out of direct sunlight.
This year I’ve tried to kill two flies with one blow, so to speak, by making a spray from a heavily-scented soap; I hope it will repel chewing insects and perhaps even some grazing rodents. Any strong odor will do–lavender, sandlewood, clove–if it smells good to us it’s probably irritating to more sensitive creatures. I created a spray from the very pepperminty Dr. Bronner’s Magic Soap. So far it’s been quite effective on those invading horde’s of squash bugs as well the squishy fat tomato hornworms but the word is still out on keeping squeaky Chip and Dale from munching on the ‘maters.
I’m looking forward to hearing about your own soapy creations–please post your concoctions and successes/failures in the garden wars!