WRITTEN BY MOLLY E. SANDWELL

You want to grow an environmentally friendly garden that embodies all the ideals of sustainability and organic practices that you do, but there’s one problem. The pests seem to love it as much as you do. How do you keep pesky insects from devouring your organic veggies and chewing up your garden greens in a sustainable, earth-friendly manner? 

Let’s explore three simple methods to keep pests at bay without endangering the ecosystem. 

The Problem With Commercial Pesticides

Not only are there multiple human health issues linked to pesticides, these chemical-laden substances indiscriminately harm other wildlife populations and beneficial insects like pollinators. This negative effect on local wildlife damages ecosystems, having detrimental environmental effects.

Additionally, commercial pesticides can have unintended consequences, like contaminating surrounding water and soil—and the effects can linger there for years, hurting soil health and affecting earthworms and ground-nesting bees.

Sustainable Alternatives to Pesticides

Given the damaging consequences of pesticides, alternative methods quickly become the next information to seek. So what are some safe and sustainable alternatives to using pesticides?

Companion Planting

What’s one way you can eliminate the need for pesticides altogether? Companion planting is a spectacular preventative measure.

Engaging in companion planting has many beneficial outcomes. Not only can it ward off aggravating insects — it can attract favorable ones, provide weed suppression and offer shade to smaller plants. 

Insects and other pests often have a natural dislike for certain plants, finding their scent, color or sometimes even texture repellant. Make use of this natural repellency by pairing compatible herbs, flowers and veggies together.

Companion planting in home gardens for insect management repels pests in three ways: with scents, attracting pest predators and being visually distracting. Certain herbs and plants can exude odors that either mask the smells of your plants or outright repel pests. You can also fill your garden with plants that attract pest predators or visually distract insects by providing a variety of plants in different hues, heights and textures.

What are some examples of companion planting for pest control?

• Plant basil and marigolds alongside tomatoes to deter thrips
• Sage and thyme can hamper moth populations on brussels sprouts
• Nasturtiums, marigolds, and onion can lessen cabbage worm damage in cabbage
• In sweet corn, intermixing flowering plants like cowpea, buckwheat and sunn hemp can attract the foes of corn earworms
• Nasturtiums and marigolds will reduce damage from squash bugs and cucumber beetles
• Sweet alyssum and African marigold can encourage the presence of aphid predators

Looking for more info on companion planting? Check out the Farmer’s Almanac Companion Planting Chart for a list of more helpful plant pairings.

Attracting Insect Predators

Instead of waging war with garden pests, consider attracting some of their natural predators to do the dirty work for you. 

Birds and bats are wonderful insect predators. Make your garden more attractive to these inhabitants by selecting native plants that draw them in. Bats as well are voracious insectivores, consuming as much as 600 insects an hour—some of their favorite dishes include beetles, crickets, moths, leafhoppers, chinch bugs and mosquitoes. 

Bats also pollinate flowers and spread seeds. Contrary to popular belief, they do not carry diseases. Setting up a bat house or bat box for local bats to snooze in during the day encourages them to patrol your yard at night. You can extend a welcome to these beneficial residents by building a bat box to encourage night-time predators to feast on garden pests.

Frogs and toads are also natural predators, consuming slugs, snails and other invertebrates. Toads are valuable carnivores, feeding on slugs, beetles, flies and crickets with larger species even eating small rodents. Frogs are amphibious creatures drawn to water, so a shallow bin filled with rocks and water can attract garden frogs who will feed on pests.

Consider planting native plants in garden beds to offer shade and cover to attract these amphibious visitors or building toad houses to shelter your herpetological friends. Frogs and toads have porous skin, so refrain from using pollutants like chemical fertilizers and pesticides to encourage their presence. 

Ladybugs are another example of using predators to control insect populations as these pretty little beetles devour aphid populations. But abstain from buying ladybugs—purchased ladybugs are often not native, and once released will fly for miles before eating insects or laying eggs. In 48 hours, only 5% of those beetles will remain in your garden. 

Additionally, non-native ladybugs can spread parasites and diseases to your local ladybug population, harming them. Instead, attract your native ladybug community by planting attractive flowers like sunflower, alyssum, yarrow, dill and coriander which provide nectar and pollen for ladybugs.

Homemade Pesticides

A last and final resort to take, for when preventative measures don’t work, is to create your own natural pesticides. 

One popular low-toxicity insecticide is neem oil. An extract of the neem tree, neem oil will disrupt the life cycle of insects in all life stages (whether they be eggs, larvae or adults) but won’t harm bees, butterflies and ladybugs. It is biodegradable, nontoxic to pets and wildlife (with exceptions to fish and aquatic animals), and won’t pollute groundwater. It is also effective against fungal infections and powdery mildew on plants.

Other remedies suggested for sustainable alternative pesticides are oil sprays and soap sprays. Oil sprays deter aphids, thrips and mites, while soap sprays can address whiteflies, beetles, mites and aphids. 

Note, DIY insecticidal soaps and oil sprays only work on contact, not after they have dried, so they cannot be used as a preventative measure. Be sure to apply these sprays either in the morning or evening to prevent heat damage to leaves. Multiple applications every 4 to 7 days may be needed to control severe infestations.

DIY Garden Pesticide Instructions

Follow these simple instructions for simple, DIY insect repellants:

• Neem Oil: Dilute 2 teaspoons of neem oil with 1 quart of water and spray on affected plant foliage in the early morning or evening.
• Oil Spray: Combine 1 tablespoon castile soap with 1 cup vegetable oil. Add a few teaspoons (anywhere between 2-8) of this mixture to 1 quart water and shake before spraying on afflicted plants in the morning or evening.
• Soap Spray: Blend 1-½ teaspoons castile soap into 1 quart water and spray on pest-ridden plants in the evening or early morning.

What insecticides should you avoid? Steer clear of diatomaceous earth, boric acid, capsaicin and pyrethrin as these are toxic to bees.

Final Takeaways

It’s really not too challenging to stay away from chemical pesticides and promote sustainable practices for dealing with garden pests. Use preventative measures like companion planting and attracting insect predators to keep pest populations low. If pest infestations do occur, tackle them with natural or DIY options and remedies.