Understanding Good Bugs vs. Bad Bugs For Your Garden
Controlling pests naturally for a balanced garden ecosystem.

When homeowners notice insects taking up residence in their gardens, they can be wary of the multilegged critters’ intentions. A quick fix might be a run to a home and garden center for a one-size-fits-all insecticide. While this option will obliterate unwanted visitors, broad-spectrum control eliminates both good and bad insects—which can be detrimental to the natural ecosystem of your yard. But there’s a better way. Instead of applying pesticides, study the interactions among the inhabitants of your landscape, both beneficial and harmful.
Integrated pest management is a simple approach. The end goal is not to eradicate pests but to mitigate them using their natural predators. Beneficial insects and wildlife pollinate plants or perform pest control by eating unwanted insects or using them as hosts for their young.
Certain plants, especially many herbs, attract the good guys, while others repel pests. Try yarrow (Achillea spp.) for lacewings, ladybugs, hoverflies and parasitic wasps, and tansy (Tanacetum vulgare) for ladybugs. Other known attractants for beneficials are dill, alyssum, coreopsis, cosmos, marigold, nasturtium, parsley and savory. Four-wing saltbush (Atriplex canescens) and local sunflowers are also good native plants to include.
To repel insect pests, try wormwood (Artemisia spp.) for ants, aphids, fleas and mosquitoes; basil for aphids, flies, mosquitoes, spider mites and tomato hornworms; mint for ants, aphids and whiteflies; and lavender for ants, aphids, caterpillars, crickets, ticks, fleas, grasshoppers, mosquitoes and silverfish. There are many more herbs with repellent qualities. Your local nursery can make recommendations based on your garden’s particular needs.
Beneficial insects can be purchased at retailers such as Arbico Organics in Tucson (arbico-organics.com) or through online sources such as Planet Natural (planetnatural.com) and Amazon. Before you buy, research the proper time of year and the best time of day to release beneficials so you don’t watch your money fly away. You will need to add on an ongoing basis to encourage biodiversity until your garden can primarily take care of itself.
The Simple Solution: Go Organic
While a hearty garden is a complete ecosystem that includes healthy soil, a balance of indigenous insects and pollen- or nectar-producing plants, there is no magic bullet for pest control. “You have to be analytical in your thinking,” says Phoenix-based gardening expert Dave Owens, also known as “The Organic Garden Guy.” “You can’t just treat everything with a single beneficial insect or pesticide.”
While there is a plethora of natural pesticide recipes and products that can be found online, Owens recommends two surprisingly simple solutions for controlling unwanted garden pests.
- Water: “By far, water is your best organic spray,” says Owens. “If you have aphids, wash them off. Before they can crawl back up on the plant, they starve to death. If you have an infestation of spider mites on Italian cypress, wash the plants off every three to five days. Adding a little bit of liquid soap will take the solution even further.” The fatty acids in the soap dissolve the insects’ exoskeletons.
- Food-grade diatomaceous earth: This powder made from naturally occurring, soft siliceous sedimentary rock is a highly effective natural pesticide. Owens notes that one $5 bag of the compound can control pests in the garden and home for up to five years. “Apply a very light dusting to plants and to the soil, around your home, inside and out. It’s safe around pets and children and is one of the best pest management solutions.”