Expert: Mike Mascio - 6/14/2007

Question
I am a 1st year container gardener, and have recently had my first experience with pests.  2 weeks ago, aphids eating my ornamental sweet potato vine (I treated with a diluted dish soap and oil solution I saw online - I want to stay organic), which seemed to work well (except it almost killed my eggplant - too oily?).  

But now, the plant next to it - a "King" Coleus - is peppered with holes.  After some research, I suspected a caterpillar - which I finally found this early a.m. - but I cannot find an organic solution.  Any suggestions?  I think it's a cabbage looper, it was a green and moved like an inchworm.  Thanks!

Answer
Yuki, based on your description, caterpillars may be the issue, but do not rule out flea beetles. They are notorious this time of year for damaging plants by eating hundreds of little holes in the foliage. They are especially prevalent around eggplant.

I always recommend organic controls, and the best on the market today for caterpillars is BT. BT is an organic insecticide, which is short for bacillus thuringiensis, more commonly sold under the brand names Dipel or MVP. It is a dust that is non-toxic to humans and beneficials but highly effective against caterpillars and hornworms.  You can purchase this product through on-line catalogs such as Gardens Alive or locally at many garden centers.

For flea beetles, I recommend a combination of pyrethrum and rotenone. These are sold as one solution or separately at most reputable garden centers or nurseries. They are organic controls which are non-toxic to humans and pets.  Be sure to also apply it to the soil since that is where the flea beetles hide and rest between feedings.

For great organic products, you should review the following two websites for everything you will need for pests and disease control:

http://www.planetnatural.com

http://www.gardensalive.com

Good luck, and write again if you more questions.

Regards,

Mike