Watermelon radish freshly pulled in a sunny garden

How to Grow Watermelon Radishes From Seed

By Maxim Kaufman — Founder & CEO, Organo Republic

Updated July 2026

Watermelon radish is a beautiful heirloom daikon type with pale green-and-white skin that hides a vivid magenta-pink interior, just like a tiny watermelon. Sweeter and milder than most radishes, it is prized as much for its stunning color as its flavor. A fall crop, it matures in about 55 to 65 days from a late-summer sowing and grows to the size of a small apple. Sliced open, it is one of the most striking vegetables in the garden.

This is the quick guide to Watermelon. For the full step-by-step on starting seeds, sowing, feeding, and troubleshooting radishes, see our complete guide to growing radishes from seed.

Quick start

Direct-sow Watermelon radish seeds about half an inch deep in deep, loose soil in late summer for a fall crop. Thin seedlings to about 4 inches apart and keep the soil evenly moist. Harvest the roots in about 55 to 65 days, when apple-sized, before hard frost, for the sweetest flavor and brightest interior color.

Best tip

Watermelon radish is a fall crop, and its signature magenta interior develops best in cool autumn weather, so sow in late summer rather than spring. Give it deep soil and room to size up to about apple-sized, and keep the soil evenly moist. Harvest before hard frost; roots left too long or grown in heat turn woody, dull, and sharp.

At a glance

Botanical nameRaphanus sativus

Plant typeCool-season root vegetable (annual)

USDA zones2 to 11 (grown as a cool-season annual)

SunFull sun to part shade (6+ hours)

Days to maturity55 to 65 days

Height10 to 14 inches (tops)

Spacing1 inch, then thin to 2 to 6 inches apart

WaterEven and consistent; keep soil evenly moist

Uses

Watermelon radish is a feast for the eyes. Slice it into thin rounds to reveal the magenta center in salads, on toasts, and across a crudite platter. Its mild sweetness suits pickling, quick ferments, and light roasting, which deepens the flavor. Cut into matchsticks it adds color and crunch to slaws and grain bowls, making it a favorite garnish for chefs and home cooks alike.

Frequently asked questions

How long does Watermelon radish take to grow?

Watermelon radish needs about 55 to 65 days, so it is a fall crop. Sow it in late summer to mature in cool autumn weather, which brings out its sweetest color.

What does a Watermelon radish look like and taste like?

Outside it is pale green and white; inside it reveals a vivid magenta-pink flesh. The flavor is mild and slightly sweet, less peppery than salad radishes.

What is Watermelon radish best used for?

Its dramatic color makes it a showstopper sliced raw into salads, arranged on platters, or cut into rounds for garnishing. It is also lovely pickled or roasted.

Any tips for growing Watermelon radish?

Sow in late summer for a fall harvest, as heat and long days make it woody and dull-colored. Give deep soil, thin to about 4 inches apart, keep moist, and harvest before hard frost.

Ready to grow your own? Watermelon radish seeds give you a stunning magenta-centered radish in the fall garden. For the full step-by-step, see our complete radish growing guide linked at the top of this page.

Sale

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Price$4.99Starting at$3.99

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Want more radishes? These value packs pair Watermelon radish with other varieties:

By Maxim Kaufman — Founder & CEO, Organo Republic

Maxim founded Organo Republic in 2017 and personally selects, tests, and grows the heirloom, non-GMO varieties the company offers. Under his leadership, Organo Republic was named Agri Business Review’s Top Non-GMO Seed Variety Solution 2026.