Even though hydroponic gardeners dodge a large number of plant problems by eschewing soil (which is a home to any number of plant enemies), pests and diseases still manage to wreak havoc from time to time. Botrytis, Cladosporium, Fusarium, and Verticillium cover most of the genera of bacteria that can threaten your plants. The insects that can prove annoying include aphids, caterpillars, cutworms, fungus gnats, leaf miners, nematodes, spider mites, thrips, and whiteflies.
A few good ways to prevent infestation and infection are to:
With insects, sometimes you can pick off and crush any large ones. Or you can try to wash the infected plants with water or a mild soap solution (such as Safer Soap).
If a problem gets out of control, it may be necessary to apply a biological control in the form of a spray. Research which product will work best in your situation. Always follow the instructions on pesticides very closely.
Alternatively, there are a number of control products on the market today that feature a botanical compound or an ingredient that has been synthesized from a plant material.
On botanical compounds as controlling agents:
Over the last few years, researchers from all around the world have started to take a much closer look at any compounds present in the plant kingdom that might hold the answer to our pest and disease control problems. Many companies have even switched from producing synthetic pesticides to copying nature by synthesizing naturally occurring compounds in a laboratory setting. Extracts of willow, cinnamon, grapefruit, garlic, neem, bittersweet, lemon grass, derris, eucalyptus, and tomato have been helpful in controlling diseases and pests.
--Dr. Lynette Morgan
