Fall Garden & Landscape Pests

While most pests start to dwindle in the fall, others can plague your autumn garden and landscape.

Gardeners might be tempted to rest on their laurels by the time fall comes around, but that may not be the best idea. While many pests are dwindling in numbers thanks to dipping temperatures and others are beginning to contemplate hibernation, there are still some pests that can plague your autumn garden and landscape. Here are the ones to look out for—and what to do if you find them.


Aphids like it hot, but they can plague your fall garden if the temperatures remain warm through much of September and into the early weeks of autumn. These tiny insects have pear-shaped bodies and long mouths used to pierce plant foliage and suck out the juices. Their sugary secretions often cause sooty mold that can further harm your plants. It's not uncommon for aphids to affect nearly every plant in the garden. If you only see a few, you can first try to dislodge them with blasts of hose water. However, to combat a big aphid problem on your vegetables, flowers, or other ornamental plants, use Ortho® Insect, Mite & Disease 3-in-1 Ready To Use.

Slugs & Snails

During the fall, slugs and snails can lay over half of their eggs, each of which will hatch in 2-3 weeks. These young slugs and snails will then overwinter in your garden and start to feed in early spring, when the temperatures warm. Though they may look like they're slow, slugs and snails can destroy seedlings and other plants (like your favorite hosta) virtually overnight. If you notice large holes in your plant leaves, suspect slugs and snails, especially if you spy their "slime trails" on the surfaces of the plants.


Bagworms are caterpillars that create unsightly bags, often more than 2 inches long, that they attach to the branches of trees and shrubs. In the fall, it's common to see these bags hanging from the branches of evergreen trees. If you only see a few of them, pick them off by hand in the fall and dispose of them. If you have a large bagworm problem, the best time to control them is in the late spring when the worms leave the bags and are vulnerable to control products. Use the Ortho® Dial N Spray® Hose End Sprayer to thoroughly treat your trees and shrubs with Ortho® MAX® Malathion Insect Spray Concentrate.

Fall Webworms

In the fall, you'll notice the webs of fall webworms forming at the ends of tree branches. (This differentiates them from tent caterpillars, which build their webs in the spring closer to the tree trunks.) Fall webworms are black-spotted, gray-haired caterpillars, and their webs can be found in just about every species of tree (with the exception of conifers).

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