How to Deal with Pests in Herb Gardens
3 of 4 in Series: The Essentials of Growing Herbs
Believe it or not, many herbs are pest-free, which is one of the reasons gardeners find these plants so easy and fun to grow. Some herbs even repel pests from themselves as well as adjacent plants. However, you may meet a handful of pests in your herb garden. If you do, act quickly to rescue your harvest, either by treating the plant or by tearing it out and getting rid of it before the problem can spread.
Check out the following table for a rap sheet of the major troublemakers.
|Pest||Appearance||Effect on Plant||Food Preference|
|Aphids||Tiny sucking insects that congregate in groups; they may be white, greenish, or black||A severely infested plant turns yellow and dies.||Caraway, lovage, nasturtium, and oregano|
|Carrot weevil||A tiny, hard-shelled brownish bug||Carrot weevils attacks the root as well as the top of the plant.||Parsley|
|Japanese beetle||Green and copper colored bugs||These bugs are voracious foliage eaters.||Basil and echinacea|
|Leaf miner||A bug that starts as a tiny yellowish larvae and turns into small, black fly with yellow stripes||Affected leaves have meandering tunnels and blotches.||Lovage, oregano, and sorrel|
|Scale||Bugs that look like small waxy or cottony bumps||Scales feed by sucking sap, and they leave behind telltale honeydew (which, in turn, attracts ants and sooty mold).||Bay, myrtle, and rosemary|
|Slugs and snails||You know these slimy characters! But you may not always see them — they're most active at night||Slugs and snails devour foliage.||Basil, calendula, and sorrel|
|Spider mite||A wee relative of the spider||Spider mites suck plant juices, leaving telltale pinprick spots and puckering.||Angelica, germander, lemon verbena, mint, oregano, rosemary, sage, and thyme|
The pests that go after herbs may seem as varied as the herbs themselves, but here are a few defensive strategies you can take to protect your herbs:
Make sure your herbs are in good health, well-watered, and in particular have sufficient elbow room.
Remove affected leaves; pull out severely infested plants and throw them away before the problem spreads.
Dislodge small infestations with a spray from the hose; larger insect pests may be hand-picked and destroyed.
If you have to spray, try insecticidal soap, which is nontoxic. Make sure the pest you're targeting is listed on the label, and then carefully follow the directions regarding how and when to apply.
You can combat certain pests with beneficial insects, such as ladybugs or lacewings.
If you succeed in beating back a pest and later want to use the herb for fresh eating or to cook it, be sure to wash it thoroughly first!