Well-suited to the home garden, tomato plants tuck into small spaces, growing vertically on trellises. Given full sun and nurturing, tomato plants provide a savory crop. Tomato plants are also a treat to pests such as aphids, fruitworms and flea beetles. Set in place organic pest controls at the beginning of the season and be vigilant about pests while plants are growing. Healthy plants will soon provide a sweet crop of tomatoes.
Monitoring for Pests
Monitoring for symptoms of pest damage can stop pest populations from escalating. Aphids, common pests in the tomato garden, feed on plant sap and transmit viruses. Plants under attack show deformed or shriveled leaves and stunted growth, leaving fruit susceptible to sunscald (see References 5). Aphid's short life cycle makes constant monitoring an important strategy.
Another pest, the tomato fruitworm, tunnels through fruit starting at the stem end. The result is a watery fruit that matures early in the season. Look for white eggs that develop a reddish-brown ring on both sides of leaves near the top of the plant. Capture larvae before they relocate and find protection in the fruit. (See References 3)
In a balanced ecosystem, beneficial insects keep hungry pests in check. Encourage these allies to the garden by providing a welcoming environment. Insects take refuge in mulch composed of wood chips, compost, leaves or lawn trimmings. Ladybugs, lacewings, big-eyed bug and wasp parasites are just a few of your allies that munch on aphids, mites, tomato fruitworm and other pests of tomatoes. Attract these beneficial insects with nectar and pollen sources such as dill, cosmos and sweet alyssum. Tall plants, such as sunflowers, also provide shelter for many beneficial insects. (See References 1 and 3)
Garden design plays a key role in controlling pests. Crop rotation is an effective way to tamp down on pest populations. By rotating tomatoes to different parts of the garden, overwintering pests wake to plants that are not their preferred hosts.
(See References 2 and 4).
Grouping tomatoes with certain plants lends extra protection against hungry pests. Clemson University entomologist Geoff Zehnder suggests planting basil to ward off tomato hornworm and garlic to keep aphids and spider mites at bay. Another strategy is planting trap plants that pests find more attractive than your prized tomatoes. Dill is a good trap plant for some tomato worms since these pests prefer it to tomatoes. (See References 1)
Other Organic Strategies
Flea beetles damage leaves of young tomatoes. To keep these pests off newly planted tomatoes, cover plants with a row cover for a few weeks. Cutworms also devastate young tomatoes by gnawing stems. Use wood ashes around the stem for protection. For aphid infestations, hose down plants with water to dislodge pests; use insecticidal soap for severe infestations. (See References 2, Table 3)
- Clemson University; Insect Pest Management in the Home Vegetable Garden; Geoff Zehnder; August 2006
- University of California Integrated Pest Management Online; Tomato Fruitworm; F. G. Zalom, et al.; 2008
- University of California Integrated Pest Management Online; Tomato Crop Rotation; January 2008
- University of Kentucky College of Agriculture; Tomato Insect IPM Guidelines; Ric Bessin; January 2004
First published in 2001, Marie Lenahan writes about horticulture, food and green living. Her work has appeared in gardening magazines and academic journals. Lenahan holds a Ph.D. in horticultural science.