The fastest growing indoor food plants are sprouts. Mainly because they are grown in a soil-free medium and are eaten before the plant fully matures, sprouts can be harvested within five days. Seeds purchased from health food and grocery stores won't be treated with poisons or anti-fungal agents and are suited for in-home sprouting. Place mung, radish, sunflower or any other kind of seeds you like in a wide-mouthed glass jar covered with a finely woven cloth or sprouting lid. Soak the seeds overnight and rinse them three to four times a day. If kept in warm place, the sprouts will reach an edible 1- to 3-inch length within five days.
Lettuce and other greens require partial sun and cool temperatures, good qualities for indoor winter growing. With numerous species of lettuce to choose from, it is possible to make a varied indoor lettuce garden. Keep lettuce moist and you will be able to harvest most varieties within 30 days.
Radishes grow well indoors because, as root crops, they require less sun than other flowering vegetables. To speed up the germination process, sow the seeds at a depth of 1/4 inch and keep the container covered with transparent film or wrap to retain warmth and moisture. Within 25 days, your radish crop will be ready to harvest. Planting seeds every few weeks will provide you with a staggered harvest throughout the winter.
Dwarf and Miniature Varieties
Full-grown tomato and pepper plants can take up to 100 days, if not more, to mature. Dwarf and miniature varieties will mature in a shorter time period, some within 10 weeks, depending on the cultivar. Miniature varieties of lettuce, tomatoes, peppers and eggplant can be grown rapidly indoors under bright, warm conditions.