Natural garden insecticides are becoming more prevalent in garden supply stores. Once found only in organic gardening circles, these insecticides are making inroads into mainstream gardening. Despite their natural origins, use of these insecticides does carry some safety concerns. Make informed decisions before applying any substance to your prized plants.
Several effective naturally derived chemicals are marketed as insecticides. Rotenone, pyrethrum, sabadilla, neem and nicotine extracts are all derived from plants and used as methods to control insects. Different formulations are sold under different brand names, and are registered for use only in certain circumstances. Check labels carefully when shopping for these naturally derived chemical insecticides.
Insects, like people and pets, need to breathe. Judicious applications of insecticidal soap makes breathing difficult. Diluted formulations are available commercially, although some gardeners have had luck mixing liquid dish detergent with water to create their own. Insecticidal soaps work best when applied directly to insects, not to plants. In some cases, they may harm sensitive plants. Test them on a leaf or two of a plant before dousing the whole thing to ensure the plant's health is not compromised. For most effective use, they must be applied consistently until the insect infestation is gone.
As with other insecticides, natural garden insecticides should only be used in accordance with their labels. Some insecticides are safe to use on edible plants, such as fruits and vegetables. Others are only safe for ornamental plants, and gardeners need to make sure they are aware of the distinction. Other uses may be unsafe for people, pets and plants. Take care when using these insecticides near waterways and ponds.
Rose Marie Nichols McGee, gardening expert and nursery owner and author of "McGee and Stuckey's The Bountiful Container," advises that just because something is natural does not mean it is necessarily harmless. Be just as cautious with natural garden insecticides as you are with conventional ones. McGee also notes that some naturally derived insecticides are quite toxic, particularly rotenone and pyrethrum.
Insecticides of any type should only be used as a last resort. If possible, consider an integrated pest management approach instead. Insecticides, even those that are naturally derived, kill off all insect life. That includes beneficial insects, such as preying mantises, spiders and ladybugs. By inviting and encouraging these insects into a garden, you can reap the benefits of natural pest control without resorting to potentially toxic chemicals--naturally derived or otherwise.