In our first post in this series, we outlined various ways to get rid of garden insect pests without resorting to commercial chemical pesticides which can create more problems than they solve. Mother Nature, in her inimitable wisdom, has provided us with an ingenious system of checks and balances in the garden whereby pests are kept in check by their natural predators. However, this system goes awry when powerful chemical insecticides are introduced because they can end up indiscriminately killing the beneficial insects—priceless pollinators, for example—along with the pests.
One alternative we touched on previously is to make your own (DIY) garden bug repellents using herb and vegetable plants you’ve grown from seed. While not a panacea for your garden woes, they can provide some measure of relief—both in the garden and elsewhere.
Peppermint - Essential Oil Garden Spray
Peppermint’s popularity as a garden plant is a testament to the fact that it’s easy to grow and cultivate. In fact, it spreads easily and can become invasive if you’re not careful. You can harvest it and extract its essential oil to repel destructive garden insects including aphids, squash bugs, whiteflies, and beetles to name a few. You can also use it around the house to keep out mosquitoes, flies, ants, and other uninvited creepy crawlies.
For ease of application, after you have extracted the oil, you can make a spray, diluting the oil with equal amounts of distilled water and witch hazel in a glass spray bottle.
To create essential oil of peppermint, you will need the following:
- Peppermint leaves (fresh and unblemished)
- Base oil (aka “carrier oil”) such as almond, wheatgerm or grapeseed.
- Muslin or cheesecloth (for filtering)
- Mallet, pestle or similar tool
- Glass jar with tight-fitting lid
Then follow these steps to create the essential oil:
- Harvest plant leaves before flowering. For best results, harvest leaves just after daybreak while they still have dew on them.
- Wash with cool water and let them air dry.
- Gently tap the leaves to release their oils without bruising or shredding the leaves which will make separating them from the liquid more difficult.
- Place the leaves in the jar and pour in base oil to cover them.
- Shake to blend.
- Leave jar in a warm place, out of direct sunlight for 24 hours or so.
- Strain oil through the muslin or cheesecloth, removing all the peppermint and discard.
- Add a new, fresh batch of peppermint leaves to the existing oil and leave for another 24 hours. Strain out the peppermint, as before. Repeat this 1-2 more times to achieve the desired oil strength
- Make sure no plant material remains in the oil mixture or it will spoil prematurely.
Tomato Leaf Spray
Another useful garden pest repellent can be made out of the leaves of your tomato plants simply and easily as follows:
- Harvest two cups of fresh tomato leaves.
- Chop the leaves into one quart of water and let them steep them overnight.
- Similar to the peppermint oil above, strain out the plant material and use the remaining liquid as a spray.
As a member of the “nightshade” family, tomato plants’ leaves contain toxic compounds called alkaloids which kills destructive aphids but won’t harm beneficial insects.
These are just two of the many natural pest repellents you can create on your own. Stay tuned for future posts covering additional ideas.