Homemade remedies are a longstanding tradition among organic gardeners, who have had to be creative in finding ways to battle insects and diseases without the help of synthetic chemicals. In the case of fighting aphids, two homemade sprays have proven very effective in controlling aphid infestations. Organic gardeners have been using tomato leaf spray or garlic oil spray to battle aphids for generations.
While knowing how to make and use them is important, it's equally important to understand why they work.
Tomato Leaf Spray
Tomato plants, as members of the nightshade family, contain toxic compounds called alkaloids in their leaves. When the leaves of tomato plants are chopped, they release their alkaloids. When the alkaloids are suspended and diluted with water, they make an easy to use spray that is toxic to aphids, but still safe around plants and humans.
What You'll Need:
- One to two cups of tomato leaves
- Two cups of water
- A strainer or cheesecloth
- Spray bottle
To make tomato leaf spray, simply soak one to two cups of chopped tomato leaves in two cups of water. Let it steep overnight. To make the spray, strain the leaves out of the liquid using cheesecloth or a fine strainer. Add another one to two cups of water to the liquid and add it to a spray bottle.
To use the tomato leaf spray in your battle against aphids, spray the stems and foliage of the infested plant with the spray, paying special attention to the undersides of leaves since that is where aphids most commonly congregate.
Caution: While this spray is very safe for humans, some people are allergic to members of the nightshade family. If you are one of them, use care in making and applying this spray.
Garlic Oil Spray
Organic gardeners have long relied on garlic as part of their pest-fighting arsenal. Garlic contains sulfur, which, besides being toxic to pests, is also an antibacterial and antifungal agent.
The dish soap in this mixture also breaks down the bodies of soft-bodied pests, such as aphids.
What You'll Need:
- Three to four cloves of garlic
- Mineral oil
- Strainer or cheesecloth
- Liquid dish soap
- Spray bottle
To make garlic oil spray, mince or finely chop three to four cloves of garlic, and add them to two teaspoons of mineral oil. Let this mixture sit for 24 hours. Strain out the garlic pieces, and add the remaining liquid to one pint of water. Add one teaspoon of liquid dish soap. This mixture can be stored and diluted as needed. When you need to spray, use two tablespoons of the mixture added to one pint of water in a spray bottle.
To use your garlic oil spray, first test by spraying an inconspicuous part of the plant to see if your mixture harms it at all. If there are no signs of yellowing or other leaf damage after a day or two, it is safe to use. If there is leaf damage, dilute the mixture with more water and try the test again. Once you have determined that it won't harm your plant, spray the entire plant, paying special attention to the undersides of leaves.
Warning: Garlic oil is a non-selective insecticide, which means that it will kill beneficial insects (such as ladybugs, who are natural predators of aphids) just as easily as it kills the bad guys.
It's best to keep as many beneficials around as possible. This spray should only be used if you haven't seen any beneficial bugs in your garden. The tomato leaf recipe, above, won't harm beneficials, so you should use that if you're lucky enough to have some beneficials in your garden.
These sprays are easy to use, inexpensive, and effective. As you can see, even organic home remedies require care and attention to their effects. In general, use each spray as little as possible, and use it responsibly. You'll win the battle against aphids, and still have a healthy garden after they're gone.