How to Grow Radishes from Seed: Planting, Growing & Harvesting

Radishes are one of the fastest and easiest vegetables to grow from seed. They're always on our list of seeds for beginner gardeners. Radishes thrive in cool weather, making them ideal for both spring and fall gardens.

Here's how to grow radishes from seed, including when to plant, how far apart to sow them, and when to harvest.

Direct sow radish seeds. Radishes grow quickly and don't transplant well.

Planting depth. Plant radish seeds ¼” deep and 1 to 4 inches apart.

Keep the seeds moist. Seeds will start sprouting in 6 to 10 days.

Plant radishes in full sun. Even though radishes grow underground, the leaves need full sun for healthy root development.

Plant radish seeds in friable soil. Like other root crops, radishes need soil that is easily crumbled so that they can grow well-shaped roots. The roots will split when the soil is too hard or full of hard materials. (Daikon radishes can drill through hard dirt and break up compacted soil, but plant seeds in loose soil if you want nicely shaped radishes to eat.) 

Fertilizer is not necessary for radishes. They grow so quickly that radishes don’t need extra applications of fertilizer, but they do grow better in rich soil with plenty of potassium and phosphorus. You can test your soil before planting. 

Radishes can be grown in containers. When planting radishes in containers, the same growing tips apply. Make sure the soil doesn’t dry out, and give them sufficient light.

Radishes are a magnet for flea beetles. But even if the beetles eat the leaves, the radishes grow fine beneath the soil. Because of this, radishes make the perfect companion plant for eggplant, peppers, cucumber, and other crops.

Radishes can be planted in a variety of garden spots. Where other plants will take longer to reach maturity, radishes can be planted and harvested before the other plants even know they are there.

Radishes are ready to start harvesting for most varieties when they are around 1 inch across. If you wait too long to pull your radishes out of the ground, they will get tough and woody. Once harvested, radishes will keep in the fridge in a plastic bag for 1 to 2 weeks.

There are some pests that love to munch on radishes as much as you do.

Flea beetles are a common pest on radishes. In fact, radishes are often used as a trap crop to lure flea beetles away. To protect your radishes, you can try planting bunching onions and mint as companions. Floating row covers and other methods can also provide protection against flea beetles. 

Root maggots will attack the roots, and you may not notice them until you pull up a radish. Row covers can prevent flies from laying eggs. Rotating crops and beneficial nematodes can also help keep populations from multiplying.

Radishes are lovely in vegetable platters and fresh salads, or they can also add a delightful crunch to tacos and sandwiches. Try adding radishes to stir-fries and casseroles, incorporated into soups, or pickled as a tangy condiment. The spicy flavor of radishes adds a welcome kick to salads and salsas. However, when sautéed or roasted, the radish flavor is significantly more mellow. 

Most radishes grow quickly, with some ready to harvest in as little as three weeks. They're also ideal for succession planting, containers, and filling empty spaces in the garden while slower-growing crops get established. 

Even if you don’t have the rest of your garden planned out, you can get started with radishes while you plot out the rest of your space. Soon you’ll have little sprouts, and the energizing momentum will get you excited about planting the next crop.

The best part about growing your own radishes is trying the different heirloom varieties. With names like French Breakfast, Watermelon, China Rose, Easter Egg, and more, you’ll have to try growing more than one radish variety.