Our Step-by-Step Guide to Planting, Growing, and Harvesting Radishes

Radishes are one type of vegetable that can go under the radar, however, the vibrant roots are one of the most versatile to cook with and grow from seed. For example, when it comes to tending to them in your garden, you won't be restricted to just growing them in the ground outdoors—you can grow them easily in containers inside, too. "If you live in a warmer climate, or just blew past the cooler days before getting your seeds sown, consider a small batch indoors," says Sabine H. Schoenberg, the host of Sabine's New House on Smart Healthy Green Living, of growing the vegetable.

Brie Arthur, a horticulturist and author of The Foodscape Revolution and Gardening with Grains ($8.49, amazon.com), explains that the most common radishes home gardeners can grow are small, round, and reddish pink with a spicy flavor, known botanically as Raphanus sativus var radicula. "Radishes owe their sharp flavor to the various chemical compounds produced by the plant," she says. "They are also an excellent candidate for cover cropping through the cool season to help reduce weeds and build your soil." Whether you decide to grow inside or outside, we have you covered with our step-by-step guide on how to tend to the vegetable from seed to harvest.

Planting

The best time of year to plant radish seeds is in cooler weather (the experts recommend below 70 degrees Fahrenheit). "Hotter temperatures cause the plant to bolt and will inhibit proper growth," Schoenberg says. While you can grow more radish plants from leaves through propagation, Schoenberg explains that this process will rarely create a new radish bulb. So, the best process is to plant the radish from seed. "They are great to plant as companion plantings and are a great organic way to help keep unwanted pests away from other vegetables," says Schoenberg.

1. To plant, first find a spot in your garden or place your container garden in an area that gets at least six hours of sunlight a day.
   • Indoor growing: Arthur says to use a grow light to ensure the plants will grow and develop properly.
   • Outdoor growing: Seek a spot that receives more sun than shade. Arthur suggests southern sun exposure.
2. Plant the radish seeds in about 1/2 inch of moist, organic soil, 1 inch apart, making sure that you have 12 inches between the rows to allow room for the leafy tops to grow and thrive.
   • Indoor growing: Arthur says to plant the seeds in potting soil.
   • Outdoor growing: "Loosen the soil with a fork and mix in compost to ensure the soil will hold moisture without being too saturated," Arthur says.
3. To keep your supply of radishes coming throughout the summer, consider sowing a new row or section every week until the temperatures warm up, Schoenberg says. (This will give you a steady supply longer.)
4. Once planted, water deep to keep soil most but not overly saturated. (For example, you shouldn't see excess water sitting on top of the soil.)

Growing

Allow your plants to grow after planting them four to six weeks before the last spring frost and again after planting in the fall when temperatures begin to cool off (about four to six weeks before the first frost in the fall).

1. Once the radishes have sprouted, thin to about 3-inch spacings. This helps ensure each plant has ample room to grow and accounts for dead seeds that might not germinate. Radishes love a moist soil for growing and optimal flavor.
2. Give them a good watering daily with well-drained soil. If the soil seems waterlogged, let it dry out a bit more between waterings. The soil should be moist, but not saturated. Mist irrigation is a great option for these veggies.

Harvesting

How long does it take for radishes to grow until they are ready to harvest? Once radishes have grown to about 1 inch in diameter, approximately after three weeks, they can be taken out of the soil.

1. Test your radishes around the three-week mark for your desired ripeness (they are usually at their best flavor when 1 inch in diameter).
   • Note: "If you leave your radishes in the ground too long, through the heat of the summer or allow them to flower, the root will become woody and inedible," says Arthur.
2. If you do leave your radishes in the ground too long, consider consuming the leafy tops for a salad, explains Schoenberg. If your radish bolts because of some really hot weather, the bean-like seed pods are also great in salads (they will have a crunchy, spicy flavor).