If you love the flavor of vegetables straight from the garden, but you don't have space for a vegetable patch, consider growing a few vegetables indoors. Radishes, one of the easiest vegetables to grow, make great indoor vegetables. Because they require so little time and attention, they're especially suitable for first-time or junior gardeners. They grow so fast, you'll have fresh radishes for your salads in just three short weeks.
Choosing a Container
Nearly any container will work to grow radishes as long as it's at least 14 inches across. A plastic or terracotta planter works well, but radishes aren't choosy, so if you have an old wash basin or a large bowl, it will work just fine as long as it's at least 10 inches across. A clean milk carton will work if you just want to plant a few seeds, and will be perfect for a child's starter garden. Wash the container thoroughly before planting.
Preparing for Planting
Fill the planting container with a good quality commercial potting soil. If you have access to compost, a mixture of half compost and half potting soil makes a very good planting medium and will provide the radishes with plenty of nutrients. Tamp the potting soil mixture down lightly with your hands, but don't compress it, and leave about 2 inches at the top of the container to allow for watering.
Planting the Radish Seeds
Although any type of radish will grow indoors, fast-growing varieties such as Scarlet Globe or Pink Beauty will produce vegetables several days sooner. Unless you have a deep container, round (globular) varieties will be best. Sprinkle a few radish seeds on the top of the soil, and don't worry about planting too many seeds, because you can thin out the smaller seedlings once the radishes germinate. Once you've sprinkled the seeds, cover them with a very light dusting of potting soil.
Germinating the Radish Seeds
Water the radish seeds carefully with a spray bottle until the soil is moist, and cover the container with clear plastic to create a mini-greenhouse. Put the radishes where they will get plenty of light. Radishes don't do well in hot weather, though, so avoid direct sunlight on hot days. The seeds should germinate in a few days, and once they do, remove the clear plastic, but continue to keep the soil damp. Thin the smaller seedlings as needed to keep the radishes from becoming overcrowded.
Harvesting the Radishes
The radishes should be ready to harvest in about a month, depending on the variety. To ensure that you will always have a supply of fresh radishes, rotate the "crops," by planting a new batch of radishes every 10 days. Harvest the radishes as soon as they're about an inch across. If you let the radishes get too large, they won't be as tender and sweet.