Maintaining a Chemical-Free Garden

Maintaining a Chemical-Free Garden

August 11, 2022

In July, the International Union for the Conservation of Nature (“IUCN”, global authority on biological diversity) added the monarch butterfly to its red list -- 2 steps away from extinction, because of widespread use of environmentally unfriendly pesticides and herbicides, as well as deforestation for logging, urban development, and agricultural expansion.

Severe weather events have killed off millions of monarchs. Our changing climate—producing droughts, wildfires, extreme temperatures—also threatens milkweed, the only plant monarch caterpillars eat. Read more about this at

Many bees also are listed by IUCN as endangered species. In Houston, we have a small and growing number of resident Monarchs. We love seeing them! We keep Milkweed in our gardens, in hopes of seeing Monarch caterpillars each spring and fall during their 2500-mile migrations back and forth from Mexico.

A healthy garden is my best defense against pests and weeds. And, of course, the key to a healthy habitat is a high diversity of insects and plants. But sometimes, I want to protect plants from damaging critters – without hurting them.  Most store-bought remedies contain toxic chemicals, and some “natural alternatives” also can injure Monarch caterpillars and bees.  


So, what can work as a pure deterrent or repellant -- without causing harm?  Not vinegar, and not oil sprays.

Vinegar Kills Bees

Some do-it-yourself pesticide recipes recommend the use of vinegar. But vinegar can kill bees and Monarch caterpillars in your yard and garden. It contains acetic acid, which kills many insect species. Even in small amounts, most any kind of vinegar – even apple cider vinegar -- kills bees on contact. And may drive bees away by disrupting their olfactory and respiratory process.

Oil Might Suit You, But It Doesn’t Suit Me

Home-made oil pesticides, whether mineral oil or vegetable oil or increasingly popular Neem oil – or even benign-sounding peppermint oil – do work as repellants. Repelling unloved insects is my goal. Oils also interfere with insect hormone systems, making it harder for insects to grow and lay eggs. That might be okay with me. But they also suffocate them. I’d prefer not to do that.

So, what do I use to repel unloved garden pests without killing them off? 

Garlic! And hot pepper!

Garlic Pepper Spray
Use this spray to keep away rodents, rabbits, skunks, deer, raccoons, cats, dogs, bears, and flying insects that feed on leaves, flowers, and fruit. Many birds, too, find strong odors to be off-putting. Including cayenne & chili pepper as well as garlic. You might want birds at your feeders, but you probably don’t want them eating your lettuce, peppers, tomatoes, or sweet corn.

Garlic-pepper spray does not seem to keep ladybugs and some other beneficial insects out, although it reportedly can affect pollination by keeping bees away for up to three hours after spraying. But it does not hurt the bees. And it doesn’t hurt Monarchs, either.

Combine ½ cup of red chili peppers, 10-12 garlic cloves, and 2 cups of water in a blender. Process briefly, then strain into a bowl. Let the mixture stand for two days before use. To apply, spray it on vegetables, fruits, or herbs every few days.  For best results, use the solution within a week.


Helpful Reminders

Be mindful of what you are touching. Be sure to wash your hands after handling the garlic and the hot peppers, and after handling plants you’ve sprayed with the mix. Don’t get it in your eyes! 


Test the solution on a small portion of the plant first, to make sure there are no adverse effects. Spray the top of the leaves as well as underneath. But don’t overdo it; excess solution can cause damage.


Mind the weather, too. Don’t spray to any plant on a hot or bright, sunny day, as this will can burn the plant -- and even kill it. And if it looks like rain, wait until the weather clears, since any rain will wash away the new application. If it has recently rained, wait until the greenery is dry before applying to prevent the mix from being diluted with water.


Make your garden a safe haven from pests and from harsh chemicals. It’s for both you and your plants. And, for the bees and the butterflies!  


This article is edited from content prepared by ReminderMedia.