Question: Last year Japanese beetles took over my garden. Are there any organic controls?
Answer: Start with your lawn; that's where the next round of beetles will come from. They start as grubs, feeding on the roots of your turf. As they mature they transform from a grub into the green metallic-shelled beetle. Dusting your lawn with products containing "milky spore" (Bacillus popillae-Dutky) will help eliminate the grubs, but it must be used for two to three years to build up enough of this bacteria in the soil to kill large numbers of grubs. The grubs swallow the spores while feeding; within one to three weeks the grubs die. As they decompose, they release millions of new spores back into the soil. Once introduced into the soil, milky spore can last 15 to 20 years. Milky spore will not affect humans or animals, nor will it contaminate well water.
Certain beneficial nematodes are also effective in controlling grubs. Nematodes are microscopic parasitic roundworms. The two nematodes that are most effective against Japanese beetle grubs are Steinernema glaseri and Heterorhabditis bacteriophora. Nematodes may be purchased in lawn and garden shops or through mail-order catalogs.
For the adult beetles, handpicking is the easiest and most effective organic control. Make it a point to walk the garden with a bucket of soapy water. Pick off beetles and drop them into the bucket. I have even bent the branches of some plants over the bucket to shake them free!
Question: How can I keep neighborhood cats from doing their "business" in my flower gardens around my house?
Answer: It helps to think like a cat. What is it that they really want from the garden? They are looking for a litterbox — and exposed soil is just the answer. I don't have cats, but people who do have had success by scattering citrus rinds around the garden. Also there are repellents on the market that are made from citrus oils that claim to help keep cats away. Planting rue (a strongly scented plant with bitter leaves) is a good deterrent, as cats don't like the smell. Spraying cats with water helps — but that means you have to catch them in the act. Cats don't like snakes, so sometimes laying a fake one in an area that you want the cat to stay away from works. And I've been told that coffee grounds spread on top of the soil will deter them.
Question: I have beautiful gardens in the spring and summer, but by fall the color fades fast. Any suggestions for plants that provide good fall color?
Answer: There are so many plants that provide an explosion of color in the fall — and now is the time to plant them. Here are a few of my tried and true favorites: Perennials: autumn crocus, purple coneflower, black-eyed Susan, goldenrod, 'Autumn Joy' sedum, salvia, ornamental grasses, hardy mums, asters, Japanese anemone, sunflower, Russian Sage. Annuals: bachelor's button, viola, pansy, snapdragon, petunia, diascia, calendula, larkspur, nierembergia, lobelia, and flowering kale and cabbage.