What Pesticides Can Be Used for Mites on Cosmos?

Water

• Whether it is aphids or spider mites that are eating your flowers, water is the cheapest and most effective way to get rid of the problem before it gets out of hand. Spray your cosmos with a hose with enough pressure to knock the bugs off but not so much that it damages your flowers. The eggs as well as the mites will be knocked off the plants, and if repeated for two or three days, the mite problem should be taken care of.

Insecticidal Soap

• Insecticidal soap will kill mites and protect your cosmos from being eaten by more insects. Available at most garden centers, this product is very similar to dishwashing soap and is harmless to your cosmos as well as you. When using insecticidal soap, cover all parts of the plant, both the tops and the bottoms of the leaves, as both aphids and spider mites will tend to live more under the flower's leaves than on top. Insecticidal soap will rid your cosmos of mites but will not kill the eggs, so repeated use may be necessary.

Horticultural Oil

• One of the most effective ways to combat mites on your cosmos is with horticultural oil. Its application is similar to that of insecticidal soap. All affected parts of the flower must be thoroughly covered as only those mites that come in contact with the oil will be killed. Horticultural oil is more effective than insecticidal soap in that, if used at a proper dosage, it will kill both adult mites and their eggs.

Cosmos as a Pesticide

• Cosmos can be attacked by aphids and spider mites, but they are just as likely to be used as pest deterrents as they are to have pesticides used on them. Gardeners frequently plant cosmos in their garden as a means to attract beneficial insects such as ladybugs and damsel bugs. These insects eat the mites and aphids that can plague many different plants in a garden.