Trap Cropping to Control Pests
Insects can be a challenge in growing vegetable gardens. Plant a trap crop near your vegetables to attract pest insects and lure them away from your crops.
What Is Trap Cropping?
- Trap cropping is a valuable companion planting technique to protect your prized crops.
- A trap crop, or sacrificial crop, is a plant that attracts garden pests, usually insects, away from your nearby crop. It acts as a decoy, drawing the pest away from the plants and saving your crop from decimation without pesticides.
For example, Nasturtiums trap aphids, and mustard plants attract harlequin bugs.
- Trap crops can also be used to attract natural enemies or predator insects to the garden. As these beneficial insects come for the pollen on these plants, they also find the pest insects they are fond of.
Sweet Alyssum and Buckwheat are good examples. They attract wasps and hoverflies. Hoverflies feed on aphids and mealy bugs. Wasps feed on the caterpillars. Bees are also attracted to these crops, facilitating pollination.
Benefits of trap crops
- Reduces the use of pesticides. Relying on insecticides would cause insecticide resistance long term in the insect population.
- It is very economical and has potential health benefits for consumers of your vegetables.
- Preserves wildlife and is safe for pets, pollinators, and other beneficial insects.
- Improves the quality and yield of the crops.
- Helps conserve the soil and the environment
Implementing trap crops in the garden
Using trap crop plants is easy and economical - and successful if some factors are considered.
1. Not all insects like the same trap crops
A trap crop should be adequately selected to attract the particular pests you are trying to trap. If the plant is not attractive enough to the pest, it will not work.
2. Positioning of the trap crop
- Border or perimeter trap cropping is the planting of trap crops around the main crop. For some insects, it is sufficient and prevents pest attacks from all sides of the crop.
For example, Basil and Marigolds can be planted as border trap crops to protect your Garlic plants from thrips.
- When it is more difficult to stop some insects, row intercropping is used. It consists in planting the trap crop in alternating rows within the main crop.
For instance, Dill and Lovage should be interplanted with Tomatoes to protect them against the tomato hornworm.
- Do not plant your trap crops too close to your desired crop.
- How important should the trap crop be? Quantities will depend on the bug you are trying to deter, but they should probably not represent more than 20% of the main crop area.
3. When to plant the trap crop
- Trap crops are most efficient when they begin to flower or seed. Therefore, they should be established earlier than your main crop and ready when hungry pests invade the garden.
- A good starting point is planting the trap crop two weeks before the main crop.
- To further extend the pest control session, you may want to plant new trap crop plantings every two to three weeks.
4. Attract beneficial insects too!
- Trap crops should also be reinforced with adequate companion planting - planting flowers to attract beneficial insects such as ladybugs, parasitic wasps, or lacewings, which prey on the pests.
- Goldenrod, Bachelor's buttons, Black-eyed Susans, African daisies, Calendula, Cosmos, Sunflowers, and Zinnia attract a wide range of beneficial insects.
Examples of Trap Crops
Here is a list of popular trap crops targeted to attract pests that affect vegetable gardens.
|Trap Crop||Main Crop||Pest controlled||Method of planting|
|Alfalfa||Cotton||Lygus bug||Strip intercrop|
|Basil and Marigold||Garlic||Thrips||Border crops|
|Blue Hubbard squash||Cucumber beetles
Squash vine borers
|Chinese cabbage, Mustard, Radish||Cabbage||Cabbage webworm
|Planted in every 15 rows of cabbage|
|Beans and other legumes||Corn||Leafhopper
|Chickpea||Cotton||Heliotis sp.||Block trap crop|
|Collards||Cabbage||Diamondback moth||Border crop|
|Corn||Cotton||Heliotis sp.||Row intercrop|
|Cowpea||Cotton||Heliotis sp.||Row intercrop|
|Tick Clover (Desmodium)||Corn
|Dill and lovage||Tomato||Tomato hornworm||Row intercrop|
|Green beans||Soybean||Mexican bean beetle||Row intercrop|
|Horseradish||Potato||Colorado potato beetle||Intercrop|
|Hot cherry pepper||Bell pepper||Pepper maggot||Border crop|
|Indian mustard||Cabbage||Cabbage head caterpillar||Strip intercrop in between cabbage plots|
|French Marigold and African Marigold
|Medick (Medicago litoralis)||Carrot||Carrot root fly||Strip intercrop in between carrot plots|
|Napier grass (Pennisetum)||Corn||Stemborer||Intercrop
Squash vine borer
|Okra||Cotton||Flower cotton weevil||Border crop|
|Onion and Garlic||Carrot||Carrot root fly
|Radish||Cabbage family||Flea beetle
|Rye||Soybean||Corn seedling maggot||Row intercrop|
|Riverhemp (Sesbania)||Soybean||Stink bug||Row intercrop|
|Sicklepod||Soybean||Velvet bean caterpillar
Green stink bug
|Soybean||Corn||Heliotis sp.||Row intercrop|
|Sudan grass (Sorghum)||Corn||Stemborer||Intercrop
|Sunflower||Cotton||Heliotis sp.||Row intercrop|
|Tansy||Potato||Colorado potato beetle||Intercrop|
|Tobacco||Cotton||Heliotis sp.||Row intercrop|
|Vetiver||Corn||Corn stalk borer||Perimeter crop|
Tips for successful trap crops
1. Identify the pests in your garden.
2. Select a good trap crop that is more attractive to the pest than the main crop.
3. Monitor your plants regularly to prevent the insect population from getting out of hand.
4. Keep your trap crop healthy to continue to lure pests away from your crops. Attend to its needs in terms of light, water, and fertilizer.
5. Remove the pests found on the trap crop.
Insect pests found on trap crop plants need to be removed or killed. Otherwise, they will likely reproduce and then move to the nearby crop. The trap crop plants may also perish. Prune or remove your trap crop once it is highly infested. Whether you use organic or synthetic insecticides, apply them thoroughly.
6. Be ready to sacrifice your trap crop and destroy it once pest infestation is high.
7. While trap cropping can be highly beneficial, it is often not a complete solution.
Combine trap cropping with other organic pest control and companion planting techniques to raise your chances of success.
- Mixed planting to confuse pests.
- Plant flowers to attract beneficial insects.
- Repel pests without using harmful chemical pesticides. Plant plants that deter pests from your vegetables, herbs, or flowers.
- Crop rotation to avoid pests overwintering in the soil
While every effort has been made to describe these plants accurately, please keep in mind that height, bloom time, and color may differ in various climates. The description of these plants has been written based on numerous outside resources.