Question: I am growing lettuce, greens, and herbs in a container on the ground around my deck of my Chicago home. Unfortunately the slugs seemed to have found the containers and are eating holes in the leaves. What should I do?
Answer: To discourage slugs from entering your containers, I would consider bringing the pots onto the deck itself. If the containers are on the ground, slugs have easy access by crawling from the soil into the pots at night. To kill the slugs already in your containers, sprinkle iron phosphate slug bait around the plants. This organic product is safe for wildlife, pets, and people, but when the slugs eat it the iron phosphate kills them.
Another method of keeping the slugs out of a container is to attach copper flashing around the outer edge of the pot. When the slimy slugs come in contact with the copper, a chemical and electrical reaction deters the slugs from crossing the flashing and entering the container. The plants are safe and the slugs are deterred.
Question: My 'Canadice' table grape vine is prolific this year in my Ohio garden. It has lots of grapes forming --- maybe too many? Should I thin out the grape clusters?
Answer: Yes, some varieties, such as 'Canadice', can produce more grape clusters than the vine can support. This results in smaller, poorer quality grapes at harvest. The solution is to thin the clusters after bloom. With a sharp knife or scissors, remove all but one cluster per 12-inch long shoot. On shoots longer than 12 inches, leave two clusters. Overall, for an average-sized plant you shouldn't have more than 24 clusters per plant. You can also clip off the bottom 1/3rd of the vine cluster itself to force each cluster to have fewer, but larger and sweeter fruits.