Herbs are often safe from insect attacks because many herbs have such strong odors, and deter insects on their own. However, that's not a true case with all herbs or in all conditions. Hungry enough, bugs will eat almost anything. And some herbs have a light scent or hardly any odor at all, and insect predators will dine on them happily. Safe and effective pesticides can be used which keep soil clean, herbs healthy and put the bugs at bay.
An easy, economical, and organic solution for insect pests attacking your herbs is a homemade soap spray. Simply buy a liquid organic soap and add a couple of tablespoons to a spray bottle filled with water. Shake well, then spray over the affected herbs. There are also commercial insect soap sprays available in many nurseries and garden supply centers; look for the organic option. Barbara Damrosch, author of "The Garden Primer," recommends adding 10 percent alcohol to a soap spray (homemade or commercial) to help the liquid adhere to the leaves.
Plant extracts are a strong option for natural, organic pesticide for herbs. If you are having a serious problem with insects attacking your herb garden, one of these is probably your best choice. Use with caution and always follow directions on the label; even though these are natural and organic, they are still powerful poisons. Pyrethrum is made from ground-up chrysanthemum flowers; rotenone is made from ground derris root. Nicotine, sabadilla dust and ryania are other options in this category. All are strong and will kill beneficial insects as well as harmful ones, so use carefully and only when needed.
Diatomaceous earth is made from algae skeletons, which contain silicon. Bugs munch away on it and then the sharp edges of the tiny pieces wreak havoc on their interiors. Sprinkle diatomaceous earth around the borders of your herb garden and the edges of your container herbs. Use caution when applying this pesticide; inhaling it can have adverse effects on you, children and animals. Wear a dust mask and keep pets and kids away from area where you've applied diatomaceous earth.