Coreopsis (Coreopsis spp.) also known as tickseed, is a cheery, low-growing perennial that produces daisylike blooms on an easy-care plant and grows in U.S. Department of Agriculture plant hardiness zones 4 through 9. Despite its low-maintenance needs, tickseed can come under attack from various garden pests, including aphids, slugs and snails. The treatment for these bugs depends on the type of pest infesting the tickseed plants. If spraying sap-sucking pests with a strong stream of water, or hand-picking slugs, snails and chewing pests haven't worked, you may need to use chemicals.
Add 1 gallon of soft water to a 5-gallon bucket and add 5 tablespoons of insecticidal soap into the water. Transfer the solution to a hand sprayer. Insecticidal soap is a non-toxic pesticide that won’t harm people, animals or wildlife.
Spray the tickseed with the insecticidal soap to control aphids, whiteflies, spider mites and other sap-sucking pests. Spray only on a calm day when temperatures won’t rise above 90 degrees Fahrenheit.
Reapply a fresh mixture of diluted insecticidal soap every seven to 14 days until you have controlled the sap-sucking pests.
Slugs and Snails
Pour a slug and snail bait containing iron phosphate as the active ingredient into a hand spreader. Iron phosphate is generally considered safe for use around people and pets.
Distribute the bait evenly around the tickseed and garden plots at a rate of 1 teaspoon per 1 square yard. Apply the slug bait in the evening.
Reapply the slug and snail bait once every two weeks, as needed.
Mix 1/2 to 4 teaspoons of Bacillus thuringiensis concentrate with 1 gallon of water. Bacillus thuringiensis is a nontoxic pesticide that acts as a stomach poison targeting caterpillars, the larval stage of problematic butterflies and moths.
Add 1 teaspoon of a wetting agent to the diluted Bt and mix thoroughly. The wetting agent reduces surface tension allowing the Bt to adhere better to the plant.
Pour the solution into a clean hand sprayer. Spray the tickseed with the diluted Bt, making sure to cover all leaf surfaces, including the undersides. The targeted leaf-chewing insects should stop feeding after consuming Bt and die within a few days.
Things You Will Need
- 5-gallon bucket
- Insecticidal soap
- Hand sprayer
- Slug and snail bait containing iron phosphate
- Hand spreader
- Bacillus thuringiensis concentrate
- Wetting agent
- Before using, any pesticide always read the directions and warnings printed on its label. Following the manufacturer's guidelines will increase the pesticide’s effectiveness and prevent unintended harm. Check rates as they vary by brand.
- Keep the area near tickseed plants free of debris, such as fallen plant material, weeds, rocks, boards and trash. These items provide protection for aphids, slugs, snails and other bugs that attack tickseed.
- University of Illinois Extension: Tickseed
- Fine Gardening: Genus Coreopsis (Tickseed)
- Clemson Cooperative Extension: Less Toxic Insecticides
- Safer Brand: Insect Killing Soap
- Scotts: Ortho Elementals Slug and Snail Killer
- Bonide: Bacillus Thuringiensis
- Colorado State University Extension: Bacillus Thuringiensis
- Comstock Images/Comstock/Getty Images