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Myths abound in the lore of gardening, clouding issues and veiling the truth. The following are some common gardening myths, laid to rest by specialists from Virginia Tech's Extension Service.
Myth: Botanical insecticides are natural products toxic to pests but harmless to other living things.
Nothing could be further from the truth. Plant-derived poisons are only sometimes less toxic to man than synthetic agrichemicals.
Rotenone. from the roots of derris plants, is toxic if sw allowed or inhaled. Both pyrethrum and rotenone are low in toxicity to mammals, yet highly toxic to fish. The yardstick for comparing acute, short-term toxicity is the LD50 of lethal dosage needed to kill 50 percent of a group of test animals (rats, rabbits, etc.). When you compare LD50 figures, the chemical insecticides malathion and Sevin rank safer than nicotine sulfate, a botanical poison derived from tobacco.
Whether the chemical comes from a laboratory or a plant, it pays to be careful.
Myth: Fall is the best season for pruning.
This is false for several reasons. Shrubs and trees store carbohydrates (food materials) in their branches and leaves, so fall pruning
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