If you are a gardener, you are almost guaranteed to encounter problems with pests at some point. Pests can range anywhere from being a minor nuisance to being a major disaster in the home garden. The more you know about common garden pests, the better you can plan your garden to prevent, evade, or trick them to minimize damage.
Garden pests can be tiny or very large, and can appear anytime during the growing season. Once you see one, you probably already have more than one! Some of the most common small pests include slugs, Japanese beetles, flea beetles, aphids, and caterpillars. Larger nuisance animals include deer, rabbits, squirrels, raccoons, mice, and birds.
Insect pests eat leaves, suck plant juices, and burrow into fruits, vines, and roots. Mammals and birds help themselves to your produce, munch on the leaves, or dig up tender seedlings. It can be incredibly frustrating to be watching and waiting for the first ripe tomato of the year only to have a hungry animal take a bite out of it just before it’s ripe. Similarly, if you’ve been watching your plants grow and one day, you notice the leaves are full of holes, you will know it’s time to take action!
As with many situations, an ounce of prevention is worth a pound of cure. There are some fairly simple ways to prevent pests from destroying your garden.
- Prevent access to your plants
- Keep your plants extra healthy
- Confuse the pests
- Recruit pest-eating predators
- Make your garden conditions unfavorable to pests
You don’t need to use pesticides or harmful chemicals to deter most pests. It’s generally better for the health of your garden if you avoid using pesticides. Pesticides are non-specific and will kill any insect that comes in contact with them. This includes beneficial insects, like pollinators and predatory insects that eat problem insects.
In this article, we will take a closer look at 15 tips that you can use to prevent and treat garden pests naturally!
Don’t Invite Mammals Into Your Garden
Installing a fence is the easiest way to keep most mammals out of your garden. You may not be able to keep every mammal out of your garden with a fence, but you can prevent many from having access to your plants.
A fence needs to be tall to keep out deer, typically at least 6 to 8 feet. To keep our rabbits, your fence should have very small or no holes along the lower 2 feet. Squirrels can be especially difficult to deter as they can climb over or through most fences with surprising ease.
Another way to deter mammals is by removing any attractive mammal habitat from your garden area. Don’t feed the birds at the edge of your garden because bird seed is also a magnet for mammals.
Compost is also attractive to many mammals, so keep your compost pile set apart from your garden, or keep compost in a mammal-proof container. Keep brush piles and wood piles away from your garden as well, as these can provide shelter for many small mammal species.
Weeds are not only unsightly, but they can also lead to numerous gardening problems. When your plants compete against vigorously growing weeds, they are in direct competition for light, water, and nutrients. Weeds can also protect and harbor pests. Bugs can easily hide out in dense clusters of weeds, feeding, reproducing, and hiding from potential predators.
Check on your garden plants regularly. Weeds grow fast, so keep them pulled as soon as you see them sprout. The sooner you pull out the weeds by the roots, the less chance you have that they will grow and multiply.
Allowing weeds to flower and set seed will only create more weeds, more hassle, and probably more pests. Keeping your garden weed-free will help minimize unnecessary pest-friendly habitats.
Keep your garden clean to help deter pests naturally. Removing leafy debris, dead foliage, and decaying plant material can help control pests. Insects hide out in leafy debris.
During the winter, any dead vegetation left in the garden can harbor overwintering insects, their larvae, and their eggs. If you had an insect or disease infestation last year, do not leave any parts of the infested or diseased plants in the garden to reinfest this year.
It may be tempting to create a waste pile right in your garden, but it’s best to put some distance between garden waste and healthy plants. Decaying plant matter is a magnet for pests and diseases, so you will ideally want to keep your garden waste pile in an entirely separate area.
As you check on your plants, remove any leaves, stems, or entire plants that are dead, diseased, or buggy. Don’t wait until little problems become big problems. Be proactive by keeping things clean up front.
Do Some Thinning
Plants that are too crowded are a magnet for diseases. Plants benefit from excellent air circulation. Good airflow can help prevent common fungal diseases like powdery mildew and black-spot. Allowing plenty of air circulation and space to grow also helps plants stay generally healthier, and healthy plants are stronger and more resilient to pests and diseases than unhealthy plants.
Another reason to thin your plants and avoid overcrowding is to help protect them from insect pests. If you have a densely crowded patch of something tasty, any insect pest that discovers it can quickly move from one plant to another, eating its fill and laying eggs along the way.
Insect pests will also be able to find tasty plants easier if they are in large dense clusters. Pests like slugs, thrips, aphids, and caterpillars would all thrive in a densely crowded, humid foliage jungle protected from predators.
Use Good Soil
Good, healthy garden soil is a lot more than just “dirt.” Soil is a dynamic living ecosystem that is well worth the investment to create it. Start your plants off right by giving them high-quality, nutrient-rich soil.
The best way to give your soil a boost in natural superpowers is to add some organic compost. Work in the compost and then cover the soil surface with a layer of mulch to retain moisture and reduce weed seed germination.
Maintaining a well-balanced and healthy garden soil is one of the best things you can do to improve plant health. Healthy plants are robust and much more resistant to pests.
In addition to periodically working in compost, you can also try planting cover crops to add nutrient-rich plant matter to your garden and then tilling these in to improve soil quality. Cover crops often include clover or other varieties of legume, which can help add nutrients back into the soil, reducing nutrient depletion over time.
Mulch is both decorative and quite useful. Any mulch can help retain soil moisture. Organic, biodegradable mulches, like wheat straw, can help nourish the soil when they break down. Mulches also play a role in preventing some common garden pests.
Mulches can provide a useful protective layer between your vegetable plants and the bare soil where many pests hide out. Slugs, beetles, and cutworms all live in or on the soil, and vine borers bore into exposed stems.
Adding a layer of straw mulch around the base of your plants can help protect exposed stems from these pesky vine borers. A mulch layer will also prevent fruits from touching the ground and inviting other pests and diseases through direct soil contact.
Water Plants Properly
Plants can get thirsty anytime, but early morning watering has some real benefits, especially regarding plant health. Plants make very efficient use of water first thing in the morning.
Before the day gets hot and sunny, they absorb essential moisture to start the day fresh and ready to do the important work of photosynthesis. Another benefit of early morning watering is that the water has more of a chance to be absorbed into the soil and into the plant’s roots rather than evaporating in the midday sun.
As you are watering, try to water garden plants from the bottom rather than spraying the leaves. Using a soaker hose or drip irrigation system is an excellent way to get the water where it’s needed most: the roots. Some people sprinkle water on the leaves without allowing it to soak into the soil. Plants benefit from a few deep soil-penetrating drinks each week, much more than an occasional light sprinkle.
Now you may wonder, how does proper watering help protect plants against pests? As with other aspects of plant care, healthy plants are resistant plants, and well-watered plants are healthy plants. Weakened plants with water sitting on their leaves can be an invitation for pests and diseases
You can also use water to your advantage as a way to physically remove pests. I know I just said to try to keep water off the leaves, but sometimes it might actually be a good thing!
If you have a bunch of insects sitting on your plant leaves, sometimes a firm jet of water is enough to knock them off and scatter them around. While this doesn’t truly remove the pests from your garden, it can sometimes confuse them enough to give the plants a distinct advantage, all without the use of any harmful chemicals.
Enjoy the Benefits of Companion Planting
Companion planting is a common gardening practice where different species of plants benefit each other when grown as neighbors. Proper companion plants can help provide structure or support, provide shade, and help enrich the soil or generally offer improved growing conditions. Companion plants can also help attract beneficial insects and repel pests.
Companion planting can be seen as a way to confuse pests. Monocultures attract pests. A huge plot of a single-species crop will surely attract plenty of pests that like to eat that crop. In a smaller area interplanted with several species, the pests will find it difficult to congregate as their favorites are scattered in between uninteresting or possibly even repellant plants.
There are plenty of flowers and herbs that are known for repelling pests. Many plants with naturally strong odors are good for warding off insect pests and hungry herbivores. For flowers, try planting some borage, marigold, nasturtium, or tansy.
Try planting basil, chives, garlic, mint, or sage for herbal companions. To maximize the benefits of companion plantings, grow several companion plants close to the garden plants you’re trying to protect.
Practice Crop Rotation
Crop rotation is a good idea for several reasons. It can help balance soil nutrients, it can actually improve soil quality, and crop rotation is another effective way to confuse pests. If you plant the same crop in the same place year after year, pests and pathogens will tend to build up on the soil, in leafy debris, and in the general area. You are providing a steady and predictable supply of food for that pest.
Wait for 2 or even 3 years between planting the same crop or member of the same family in the same location. In the in-between years, plant a cover crop from an entirely different plant family or some other crop that may help enrich the soil, like beans or peas.
This allows time for the soil to recover and can actually increase soil fertility. It also prevents the buildup of a particular pest in the same area for multiple successive years.
Practicing crop rotation with a small garden plot can be very challenging. If you have only one raised bed, for instance, and you want to grow tomatoes yearly, you can at least plant the tomatoes in a different corner of the bed each year.
If you have 3 or 4 small raised beds, you can shift crop families in a clockwise direction each year, for example, to have a bit of healthy change.
Attract Beneficial Insects
Not all insects are pests. Many insects are beneficial to the garden setting. Pollinators help plants grow and reproduce. Predatory insects eat other insects that are harmful to garden crops. Beneficial insects will be naturally attracted to your garden if it has what they seek, primarily flowers and other bugs.
Ladybugs are voracious predators and gobble up aphids, mites, and other common insect pests. Lacewings also eat a large number of aphids. Praying mantises will eat almost any insect they can catch, including many nuisance pests.
Parasitic wasps are highly varied and find hosts in an equally diverse assortment of garden pests. None of these beneficial insects is harmful to people, but all are extremely valuable in controlling populations of insect pests.
Learn what these beneficial insects look like so you can welcome them to your garden. Many beneficial insects are attracted to flowers, such as coriander, coreopsis, dill, goldenrod, parsley, tansy, and yarrow. Once you have beneficial insects and know what they look like, protect them as good garden friends, and most certainly, do not spray insecticides on them.
Bluebirds eat a great number of insects every day, as do vireos, warblers, finches, wrens, and mockingbirds. If you put out a bluebird box during the winter, you may have bluebirds nesting by the time spring rolls around.
But establishing a bluebird box is just one way to attract birds to your yard. If you put out a bird feeder or bird bath, you can start creating a welcoming environment for various bird species.
If you want to attract birds, create a bird-friendly yard. Plant shrubs to provide perches and nesting opportunities. Grow plants that produce fruits, berries, and seeds that attract birds. Use a variety of different plants, including vines, evergreens, and of course, plenty of native species to offer the widest diversity of habitats and food sources for your insect-eating feathered friends.
Use Floating Row Covers
If you have never tried floating row covers, this can be a very convenient and effective way to deter pests. A floating row cover is simply a very lightweight fabric material that is placed over plants during part or all of the growing season. Floating row covers can be used in the early spring and late fall to extend the growing season, but they also provide a physical barrier to block pests.
Floating row covers may work best for various leafy greens because these don’t require pollination. They can prevent caterpillars from cabbage worms and cabbage loopers from invading cruciferous vegetables.
Flowing row covers can prevent flea beetles on greens, potatoes, and eggplant. They can also prevent early-season infestations on cucumbers and squashes, but the row covers must be removed during flowering so these plants can be pollinated.
Don’t Compost Infected Plants
Whenever you have a heavy insect infestation or severely diseased plants, the best thing to do is destroy the diseased plant material. Most people don’t get hot enough compost piles to sterilize their compost truly, and any remaining pests or diseases can transfer back in later!
Do not put pests and diseases into your compost, leave it in the garden, or try to work it into the soil; you will only keep the pets and pathogens around longer. Healthy compost is made of healthy plant matter (no pests or eggs, no diseased material, and no weed seeds).
If you have tried to eradicate an insect pest, but the problem keeps getting worse, it’s time to remove the problem from your garden. You can remove badly infected stems, leaves, or entire plants and dispose of them in a plastic bag.
Be sure to wash your hands and tools after handling infected plant material so you don’t accidentally transfer bugs or their eggs to other healthy plants.
Learn Correct Identification
Do you want to know the difference between good bugs and bad bugs? Learn to identify adults and larvae of both common pests and beneficial insects. Adult ladybug beetles are very familiar and easily recognized.
But can you identify the larval stage of the ladybugs native to your area? Both ladybug adults and ladybug larvae are hungry predators that feed voraciously on aphids and other pests, and both should be welcome in the garden. As a novice gardener, I removed many ladybug larvae, thinking they were pests, before I realized that they were actually very beneficial!
Learn to identify the various life stages of ladybugs, lacewings, praying mantises, and parasitic wasps. Learn to identify some of the most common pest species, such as Japanese beetles, aphids, thrips, cucumber beetles, and flea beetles.
Also, be fully aware that if you grow herbs like parsley, dill, and fennel, the caterpillars that feed on these are from beautiful swallowtail butterflies. If you want to attract butterflies, you must feed their caterpillars. Expect to lose some plants but gain some beautiful winged insects!
Try Diatomaceous Earth
If you are battling an insect pest and desperately want to try to kill it, buy a bag of diatomaceous earth. Diatomaceous earth is a white powdery substance that is nontoxic to people or plants but harmful to soft-bodied insects. Diatomaceous earth is an entirely natural product. It is the fossil remains of tiny diatoms and can act as an effective insect deterrent for organic gardeners.
You can sprinkle diatomaceous earth on the soil around your plants or directly onto the leaves and stems. Just be aware that while it does not harm most winged beneficial insects or earthworms, it also isn’t as effective when it gets wet; moisture saturates the fine diatom shell particulate and softens it a bit.
There are plenty of ways to create a healthy garden environment without using any toxic chemicals. Physical barriers can be an excellent choice to prevent pests, but this is not always a practical option. Building healthy soil, offering ideal growing conditions, and growing various plants can go a long way to preventing insect outbreaks.
You can also work to attract beneficial insects and insect-eating birds. Anything you can do to encourage strong and resilient plants will be beneficial and help create a vibrant and robust garden.