Garden Pest Management

Entomologist Doug Tallamy wisely stated, “if something is not eating your plants, then your garden is not part of the ecosystem.” These are certainly words to live by for the ecologically minded gardener, but most hope something is left to harvest as well. A holistic approach to pest management ensures that people and wildlife alike can benefit from the garden ecosystem. Use these strategies to protect crops without causing harm.

Most garden problems are mitigated by healthy soil. Plants growing soil with ideal drainage, water retention, and nutrition are stronger and healthier. They aren’t immune to pests, but are able to withstand far more damage, often enough to limp towards harvest.

Simple ways to prioritize soil health include liberal use of mulch and compost, and avoiding tillage. For more involved explanations and advanced strategies, read Soil Care from the Gardener’s Grimoire.

Even the most aggressive strategies struggle to eradicate pests entirely. It is wise to assume that some plants will be lost to pests, so always plant extra. A good rule of thumb for organic gardens is to assume pests will claim at least a third of what gets planted, so plant an extra for every pair.

Get familiar with common regional pests and plan the garden around them. Choose plants that local pests don’t like to eat, or varieties that are resistant to pests and diseases present at the site. Notice and prioritize plants that thrive without too much nursing. As tasty as a crop may be, if it gets decimated by pests year after year, that space may be better used by something more robust.

In monocultures, pests don’t have to work very hard to find the crops they like to eat and spread easily from one plant to another. Planting a variety of crops together will make each variety difficult to distinguish and infestations will spread slowly from plant to plant, giving the gardener time to intervene before all is lost.

Diversity should also guarantee that something will survive the growing season, even if it isn’t the primary crop. It is extremely risky to rely on only one type. Plant more than one option to ensure there will be something to eat come harvest time.

Some plants, particularly smelly herbs and flowers, are distasteful to many pests, and will protect the plants around them. Hide crops meant for harvest by including a few of these deterrent crops in every garden plan. French marigolds, plants from the onion family, and herbs like thyme and basil are common examples.

Gardeners can use plants that pests like as a strategic sacrifice. Pests prefer some plants so much that they will mostly ignore crops they would otherwise eat if the preferred plant is growing nearby. These distracting plants are also convenient insect pest traps. When the trap crop is infested, soak it in soapy water to kill them. Common trap crop examples include nasturtiums to attract aphids, dill to attract tomato horn worms, and radishes to attract flea beetles.

Ideally, pests never have an opportunity to ravage crops. A well constructed fence is expensive and complicated to install and maintain, but is almost always necessary where deer and rabbits are an issue. To really be worth the effort, the fence must be taller than relevant pests can jump, too narrow for them to crawl through, and may even need to extend underground to prevent pests from tunnelling under it.

Cloches protect plants on a smaller scale. Usually only one large plant or a few small plants can fit underneath. Garden centers and online stores will offer cloches that are decorative as well as functional, but suitable protective coverings can be found in many places, including the recycling bin. Wire and wicker baskets work well, and can be secured with landscaping staples. Hardware cloth and chicken wire are easy to shape into custom cloches and protective barriers. Transparent plastic or glass jars can also protect plants from frost during the shoulder seasons.

Insect netting will effectively protect entire garden beds from insects and small rodent pests. Arrange netting over a scaffold, or stakes with bottles and jars turned on top, and secure the bottom with weights or landscape staples. Make sure that there are no gaps that pests could exploit. The key to using insect netting is to set it up before pests arrive, and to avoid trapping any pest under the netting with the plants. Keep in mind that netting will exclude pollinating insects as well.

Protect fruits that are prone to pest damage by tying mesh bags around them while they ripen.

This natural powder is usually available at garden centers and online shops. Spraying it on plants creates a protective coating that is distasteful to animals, impenetrable for most insects, and even blocks harmful uv rays. It works well with seedlings, delicate branches, and tempting fruits.

Places to rest and breed can allow a pest infestation to become even more severe. Remove old and affected plants before the pests they host can spread. It also helps to know the preferences of the offending pest. For instance, slugs and snails like to hide under objects that trap moisture near the ground, so removing large leaves, logs, overturned buckets, and the like from cultivated areas can limit their population. These items could also function as a trap.

Pests that associate the garden with danger and discomfort are likely to leave it alone. In addition to deterrent plants, scare crows, windchimes, dog and cat fur, clattering pie pans strung across fishingling, and motion activated lights can contribute to effective garden defense. Predator urine is available to purchase at many hardware stores. The smell will deter mice and other small mammals from the garden the same way it discourages them from nesting in buildings and vehicles.

Sharp and prickly materials can be irritating enough to deter sensitive pests, especially if an easier meal is available. Jagged woodchips, egg shells, sticks and stones, and thorny plants will irritate paws and the bellies of slugs. Though it feels like a fine powder in human hands, on the insect scale, bentonite clay is sharp and drying. Sprinkle it around the plants that need protection. Reapply when the rain washes it away.

Though not effective against birds, spraying diluted hot sauce on plants makes them distasteful to mammals like rabbits, squirrels, and deer. It may require reapplication a few times throughout the season, especially after rain, but one taste is usually enough to dissuade these animals for some time, especially if something tastier is available.

Spotting damage early gives gardeners a chance to salvage a plant. Catching an infestation early gives gardeners a chance to form a strategy that hopefully saves the crop. If possible, spend a few minutes in the garden each day checking for signs of pests. Check both sides of leaves and stems for insects and eggs. Removing eggs will disrupt the life cycle of pests, hopefully before they become problematic. Animal droppings could indicate the presence of animals that can’t be observed directly.

In a healthy ecosystem, predators keep pest populations balanced. One way to deal with infestations is to let natural predators restore balance over the years. Nothing attracts predators like an abundant food source. Birds are effective predators of many insect pests, and are easy to attract to the garden with birdfeeders.

Where predators are not abundant, fake ones may spook pests away from the garden. Rubber snakes and owl statues can dissuade mice, rabbits, squirrels, and other small animals.

Gardens and gardeners can both benefit from insectivorous livestock. Chickens, ducks, and quail will happily turn common insect pests into manure that feeds the soil, as well as meat and eggs which feed the gardener. Ducks are said to be relatively gentle with garden plants, but chickens will scratch up and eat crops if given the chance. It’s best to restrict chickens to areas between cultivation.

Some gardeners like to purchase and release the larvae of lady bugs and praying mantises to counter insect pests. This is risky. There is little guarantee that these insects are appropriate for the environment. In fact, many of the insects sold as lady bugs are actually an invasive lookalike.

Ideally, predators are present long before pests become problematic. Providing habitat is a good way to support them. A pond can host dragonflies, toads, and frogs. Small shelters will help amphibians safely move about the garden. Log piles host snakes that eat slugs, snails, and small rodents. When left standing, dead plant stalks shelter many beneficial insects over the winter.

Many pest predators are insects, and are affected by the same sprays used to eliminate pests. Pesticides do not discriminate, and are more accurately described as insecticides. Choosing not to use them is another way to support these predators in the garden.

Some pests are invasive and have no natural predators. Even the ones that do have predators can ravage crops without intervention.

Picking insect pests off plants by hand and putting them in a bucket of soapy water is a tedious but effective way of removing them.

Traps are less tedious, and can be effective for larger pests as well. The classic example is beer traps: slugs can’t resist beer. Sink a dish of it into the ground, and overnight they will crawl in and drown. Empty the dish and repeat. A damp plank or slice of potato works similarly. Larger, more elaborate traps are necessary for mice, rabbits, etc, but gives the gardener an opportunity to relocate unwelcome guests.

Sprays that kill insect pests should always be a last resort, because they can also kill beneficial insects. Applying them in the evening after bees and the like have gone to sleep can help minimize unintended casualties. Restricting sprays to only a few vulnerable plants or varieties should also protect insects that prioritize other plants. Choosing insecticides thoughtfully can minimize harm to people, animals, and friendly bugs.

Bacillus Thuringiensis (BT) is a naturally occurring soil bacteria that kills fungus gnats, caterpillars, and mosquitos when they eat it. It must be digested to be effective, so only the insects that actually attempt to eat treated plants will experience the effects. This is the perfect defense against caterpillars, but many caterpillars are important to the ecosystem so make sure somewhere in the garden is safe for them. It is safe for humans to eat right in the garden, though it is always recommended to rinse produce first. The effectiveness of the spray wears off in heat and sun, so frequent reapplication is necessary for ongoing protection.

Cold Pressed Neem Oil is a popular natural insecticide that also has mild fungicidal properties. The azadirachta in quality neem oil slowly kills soft bodied insects by disrupting their hormones and feeding behaviors. Be sure to use this spray in the evening because it will affect bees and butterflies as well. Caution is still warranted because the effects linger on leaves long after application. Insects with hard exoskeletons and eggs are unlikely to be affected by neem oil. Mix neem oil with water and an unscented dish soap with no degreasers so it is easy to apply with a spray bottle.

Safer Soap kills soft bodied insects like aphids when hit directly. Mix it with water and spray.

Spinosad is a more broad spectrum and immediate. Spray it at night to avoid harming bees. Once it’s dry, it is no longer harmful to them.

Pyretherin is a last resort even among these natural insecticides. It is a powerful poison extracted from a flower. When it hits insects directly, it disrupts their nervous system and kills them quickly. It will not affect insects with a hard exoskeleton, or eggs, and has no residual effects. Be very careful with this insecticide because it is also poisonous to people and animals.

Whatever insecticide is appropriate, be sure to follow the directions and use caution to keep everyone, plants, animals, friendly insects, and people, safe.

This section about natural pesticide options is largely informed by “How to Eliminate All Pests in the Garden (No Mercy)” from The Gardening Channel with James Prigioni, published to Youtube one July 23 2025.

In some cases, pest pressure may force gardeners to shift strategies. This may mean choosing to grow something else, starting seeds indoors to transplant them when they’re more robust, or even growing plants in containers to keep them inside. Sometimes the best way to fight pests is to avoid the battle all together.

The best information about pests and effective strategies will come from gardeners working in the same area. Local extensions will also have detailed guides about pests that are common to the region.

There are many strategies to effectively manage pests without causing harm to the other things living in the garden. When you strive for balance instead of exclusivity, everybody gets to eat.

Questions? Suggestions? Concerns?

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