There are few better uses for a kitchen windowsill than an indoor herb garden. You add a touch of green to the kitchen and at the same time produce plants that can be useful in cooking--fresh basil leaves for your soup, fresh chives for your baked potato, fresh parsley as a garnish. Herbs also are remarkably easy to grow indoors, although they do require regular care and maintenance.
Thoroughly clean your pots and fill the bottom third with gravel and then apply a thin later of potting mix, enough so that when the plant is placed inside the pot the top of the root ball is about an inch below the rim of the pot.
Remove herb plants from the plastic pots they came in and place in the center of the pots on the potting mix. Fill in the rest of the pot with more potting mix and with your fingers gently tap down on the dirt to compact it just enough to secure the plant.
Place pots on a kitchen windowsill or any windowsill that gets at least five or six hours of direct sunlight a day--generally a window that faces south. Avoid placing the potted herbs in areas where they might receive a draft or a burst of hot, dry air, such as near a heater vent. Your goal should be to keep the temperature fairly constant, up to 75 degrees F.
Water your herbs at least once a week, enough to keep the soil moist but not soaked. Also lightly spray them so they can absorb water through their leaves, particularly if the air inside your home is dry. Summer air-conditioning and winter heating can really dry out a house, and dry air can lead to browning. Your optimum humidity level is 50 percent.
Trim your herbs regularly to encourage growth. Use sharp nail scissors. Cut the stems just below a cluster of leaves to encourage new growth, and be sure to trim any buds because flowers tend to soak up nutrients and leave the herbs with a bitter taste.
Watch for aphids and other pests. Either hold the plants under a gentle stream of water to wash away the bugs, or spray with a tea you can make yourself by pouring boiling water over spearmint or rue leaves and letting them steep for 15 minutes. This "tea" is a natural insect repellent.
Nutrients gradually leave the soil as they are used up, so keep a bottle of indoor plant fertilizer on hand. Use sparingly, according to the directions on the bottle.