You’ve probably heard the advice to those who like to go hiking in bear country: You don’t have to be the fastest runner in your group, you only have to be faster than your slowest friend.
In the gardening world, trap plants are the equivalent of that slow friend.
Trap crops have long been used by farmers to draw pests away from the main crop. Sometimes they are the same cultivar planted a few weeks earlier than the protected crop. This gives them a head start so the pest insects will start feasting before the main crop emerges. They are planted on the perimeter because the marauding insects will encounter them first before heading further into the field. Once the trap crops are covered in pest insects, they are either treated with pesticide or removed.
Trap crops can be useful to the home gardener as well. Perhaps you’ve noticed that out of maybe 12 kale plants, one will seemingly collect all the aphids in the neighborhood. Don’t try to figure out what that one plant did to deserve such a fate – just wait until it’s saturated before pulling it and putting it out of its misery. I recommend disposing of it in the trash rather than trying to compost it.
Trap plants can also differ from the protected crop. Planting these combinations can benefit your garden’s health as well as provide some interest. Here is a short list of some trap plants and the pests they protect against:
Hubbard squash attracts cucumber beetles, squash vine borers, and squash bugs.
Sunflowers attract stink bugs.
Nasturtiums, dandelions, and okra attract aphids. Keep in mind that while these plants bring in aphids, they will also attract ladybugs to eat the aphids. If you see a dandelion covered in both aphids and ladybugs, leave it until the ladybugs have finished eating and leave. You don’t want to throw away a bunch of perfectly good ladybugs.
Mustard attracts harlequin bugs.
Radishes attract flea beetles (a major pest of eggplants), harlequin bugs, and cabbage maggots.
Marigolds attract root nematodes and repel cabbage moths. They supposedly repel rabbits, but the rabbits in my neighborhood seem to be the exception.
Companion plants can be trap plants, but they can also be attractive to beneficial insects or repellent to pest insects. They are also used to improve soil conditions, either by breaking up heavy soil or, in the case of legumes, make nitrogen available to plant roots.
Some companion plant combinations include:
Corn, beans, and squash (a.k.a. Three Sisters)
Spinach and strawberries.
Dill and squash/cucumbers.
Alyssum is very attractive to beneficial insects, is low-growing, and re-seeds readily. I recommend planting it wherever you can fit it in.
Garlic and onions are repellent to a number of pests, and their seed heads are attractive to beneficials as well.
Los Angeles County
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San Bernardino County
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