How to Treat Garden Pests

Meet the top pests that can damage your plants and infest your garden.

You plant a nice garden, you see sprouts and buds and birds and butterflies. Then suddenly, the wrong crowd shows up. Slugs, aphids, mites, and other nasty pests treat your plants as if they were a tray of hors d'oeuvres. Here are a few of the more common uninvited guests you'll find in your garden and what to know about them.


Slugs are never going to win any beauty contests. There are over 30 species of these slimy creatures. They seek out damp, cool places to hide. Lift a rock or a piece of wood in your yard, and you might see a few. Slugs are most active for two hours after sunset and two hours before sunrise. They munch on seedlings and ornamental plants, and they particularly love hostas. If you see large round holes in your plants' leaves, you're looking at the remains of a slug feast.

Spider Mites

Spider mites are like little garden vampires. They bite and suck the fluids out of your plants. They can leave white or yellow speckles on plant leaves, or even kill the entire plant. They are tiny and hard to see. When the infestation is bad, you'll see fine silk webbing on your plants.

spider mite


These sap-sucking insects can weaken your plants. They can pass viruses from one plant to the next, and generally stunt your plants. Look for them under leaves and along stems. While they have natural predators, you can also protect your plants from aphids with control products.



These are the adolescent stage of butterflies and moths, but not all of them grow up to be beautiful monarchs and swallowtails. Some, like the tomato hornworm and gypsy moth caterpillar, are true pests. They can strip a plant of its leaves in no time. Many have a favourite type of plant in your garden they prefer to munch on.