When growing herbs indoors , there are 7 key areas to control for the best results. Once you manage to control these areas, you can grow otherwise difficult herbs indoors, even if they would not thrive in your outdoor conditions.
Some herbs can be brought indoors from the outside garden, when the cold winter months normally cause them to die back and go dormant. In order to do this, your indoor growing area must have adequate light, which means a southern exposure ideally with about eight hours of sunlight a day. Most gardeners do not actually have this sort of light, and although the window is sunny, the herbs can not thrive.
If you do not get enough light from a window, you can supplement your herb's growth with growlights. These special lights differ from regular light bulbs because they shine with the full spectrum light that plants require. There are complete setups with pots and overhead lighting available or you can purchase the grow lights separately and be sure they are placed according to directions. An easy alternative is to purchase fluorescent shop lights, and keep the light suspended within 4 inches above the growing herbs. Indoor grow lights need to be replaced on a schedule to be certain that they are giving off the proper strength your plants need. There are clear signs that you need to replace your grow lights, so be certain to read the manufacturer's instructions.
Other concerns with indoor herb gardening are temperature and moisture. For some plants, the air inside is too dry during the winter and additional moisture needs to be provided by misting or placing the herb's pot onto a tray full of pebbles with water poured into it. While this tray water evaporates, it adds humidity around the plant. You may be surprised at how often you have to refill the tray.
Pests can also become a problem for indoor herb plants. Because there is no winter cold to kill off eggs, sometimes there will be a large number of tiny sucking insects that will suddenly appear around your herbs. If you see tiny insects either crawling or flying around your herbs, simply prepare some tepid, soapy water in the kitchen sink or a large, deep bowl. Keeping your hand over the base of the herb plant, tip the pot over and swish the plant around in the soapy water a few times. The soap will kill the bugs without injuring the plant itself. If you can not flip the herb over, a spray bottle of the same soapy water can be sprayed on until it drips over the leaves. Be certain to spray the undersides of all the leaves because this is where the eggs and hatchlings usually hide. If you would rather purchase your sprays, be certain they are labeled organic, so they don't harm the plants or the environment. I have had luck buying products from both of the following companies, but there are dozens more popping up all the time.