Q. What organic pesticides should I use in a garden?
Seventy percent of the world's most annoying and harmful weeds call the U.S. home, causing herbicides to dominate national pesticide sales. Weeds not only steal water and nutrients from your plants but also often produce allergens and look unsightly. Pulling weeds by hand and avoiding compost and mulch that may contain weed seeds can help control these pests, but extensive existing problems may require herbicides. Herbicides appropriate for use in an organic garden include soft soaps, which prevent the gas exchanges plants need to survive, and biopesticides, plant diseases that attack specific weeds.
Organic pesticides can seem less dangerous than synthetics, an incorrect and potentially dangerous assumption. Generally speaking, however, you should read labels closely, checking that the pesticide is safe and approved for the plant you intend to use it on. Pesticides like soaps and plant-derived treatments can harm some beneficial plants. Always follow instructions on the label precisely with respect to the amount of product to use, time of day and weather conditions for safest use, protective clothing to wear and other precautions you may need to take. Keep products stored in their original containers where you will continue to have access to application instructions. An integrated pest management approach is probably the best approach, depending on what pests you have found on what plants. Another thought for you is to look for ways to control pests without pesticides. There is abundant information to be found on the Internet. Here, for example, is a link I found that you might like to see http://www.sustainablebabysteps.com/organic-gardening-pest-control.html
Here also are two books which have information that might be helpful:
They are available as eBooks to PHS members, but you may check for them at your library. There is a good chapter on controlling insects without chemicals in the second book.