When dealing with pests, I find that usually no action is needed – except with slugs, I handpick them as soon as possible. Experience has taught me that with good planning, I can prevent many pest problems before they happen.

First, I rotate my crops annually so they’re not planted in the same spot year after year. This makes it harder for pests to find your veggies. Second, I plant plenty of annual flowers and flowering herbs in my vegetable beds. These attract beneficial insects such as ladybugs, hover flies, and lacewings, which can help control pest populations. Finally, I use garden covers (insect barriers, row covers or deer netting), which help prevent pests from reaching your crops.

Of course it’s important to note that not all bugs are bad and it’s always a good idea to take a closer look before you reach for the spray bottle. According to Jessica Walliser, the award-winning author of Attracting Beneficial Bugs to Your Garden, most insects in our gardens are either beneficial or neutral. “Less than 1% of the million identified insect species on the planet are classified as known agricultural or human pests,” she says. “That means that most of the bugs you find in your garden are causing it no harm, and many are helping you control pests, pollinate flowers, and break down organic matter.”

And as anyone who gardens in deer country knows, not all pests are insects. Larger critters such as deer, rabbits and groundhogs can also destroy food and flower gardens. I see deer daily in my yard and rely on an electric fence to keep my vegetables safe.

Seven Most Common Garden Pests

Slugs

Slugs were the first garden pest I battled and they continue to plague my crops each year. They leave large holes in the foliage and tell-tale slime trails on the soil. Walliser says that slugs are most active on cloudy or rainy days and at night, so those are the best times to go on a slug hunt. I do a daily hunt in spring to help reduce the population. You can also use beer or yeast traps, organic pellets and baits, or a barrier such as diatomaceous earth to reduce slug damage.

Aphids

Aphids cluster under leaves and on the tips of flower buds and young shoots. They’re small insects with pear-shaped bodies that can be green, brown, gray or black. These pests damage plants by sucking the juices from the leaves, flower buds and flowers. When I spot aphids, the first thing I do is take a peek to see if any ladybugs or lacewings are nearby. Both of these beneficial insects eat dozens of aphids per day and if they’re on the job, I know the outbreak is under control. If after a few days I don’t see any good bugs among the aphids, I get out my garden hose and knock the aphids from the plants using a strong blast of water. After they fall to the ground, aphids become prey for ground beetles and other insects.

Imported Cabbage Worms

The larvae of these worms, which are hard to spot, can quickly devastate a cabbage, broccoli, kale or cauliflower patch. Slugs are often blamed but if you take a closer look, you’ll likely spy these pale green larvae that grow up to an inch long and tend to blend in with the leaves or plant stems. Cabbage worms arrive on your plants when the adults – white moths with black spots – lay yellowish, bullet-shaped eggs on the undersides of the foliage.

I use insect barrier fabric or lightweight row covers in spring as soon as the seedlings are planted to prevent the moths from laying eggs. These barriers can be left in place until harvest, or you can remove them once the plants are growing well. I also plant a variety of flowering plants with my vegetables to encourage predators that feed on cabbage worms.

Colorado Potato Beetles

These not only feed on potatoes, but also related crops such as tomatoes, peppers and tomatillos. The adults are almost a centimetre long and have rounded red bodies with tan stripes. The reddish larvae are just over a centimetre long with rows of black dots. Both the adults and the larvae can do considerable damage to plants, stripping the leaves down to their stems. I find the most effective way to reduce Colorado potato beetle damage is by practicing crop rotation (the adults overwinter in the soil) and placing lightweight insect barrier fabrics over the bed as soon as I plant seed potatoes in mid-spring. Potatoes don’t need to be pollinated to produce a crop, so I leave the barrier in place until harvest. Make sure the material is weighed down by burying the edges in the soil or using garden staples. If you leave a gap for the adults to crawl under, you’re simply trapping them with their favorite food source.

Cucumber Beetles

There are two main types: spotted and striped. In both cases, the adults grow to about two-thirds of a centimetre in length. They love cucumber plants, but you might also find them on related crops such as squash, gourds and pumpkins. As the adults feed, they leave ragged holes in the leaves. Even worse, they can transmit diseases such as bacterial wilt. If cucumber beetles are an annual pest in your garden, grow wilt-resistant cultivars of susceptible plants. Examples include Saladin and Salad Bush cucumbers or butternut squash. Once again it helps to use a lightweight insect barrier. Place it over top of cucumber beds when first seeded or planted and leave it in place until the plants begin to flower. At that point, remove the cover to allow pollination. You can handpick cucumber beetles, but it’s hard to stay on top of them by relying solely on this method. Walliser recommends mulching the soil around the plants with straw to reduce egg laying.

Deer

I’ve found the only effective way to prevent deer damage is with a barrier such as a fence. For years I used seven-foot tall netting hung on wooden stakes around my garden to keep the deer out, but it wasn’t very successful. Sometimes the deer would jump over the netting (seven feet high!), and other times they would run through it tearing the plastic netting. About seven years ago, I installed a four-strand electric fence and it’s been an effective way to keep my vegetables safe from the many deer that cross our property every day. For small spaces, such as a single raised bed, chicken wire or deer netting hung on hoops will protect edibles from deer. Walliser says you can also use scare tactics such as motion-activated sprinklers to surprise deer who wander too close to your vegetable beds.

Rabbits

They may look cute and fluffy, but rabbits will happily eat all of your lettuces and beans. The most effective way to prevent rabbit damage is with a barrier such as chicken wire. To prevent burrowing, the wire should be three feet tall and buried six to twelve inches below the soil surface. If you have only a few plants you’re trying to protect, create chicken wire cages by looping the wire into a cylinder shape and securing it with zip ties. Place these cages over susceptible plants and secure them to the soil with garden staples.

While you can never eliminate all harmful pests from your garden, with a bit of planning you can limit the damage they cause.

Niki Jabbour