Getting Started

Start Seeds Inside:
Starting radish seeds indoors is not recommended because radishes grow quickly and do very well when directly sown into the garden bed or containers.

Direct Seed:
Direct seeding radishes during the cooler months allows for quick germination and rapid growth, taking advantage of mild temperatures and shorter days in Florida.

Transplant Starter Plants:
Transplanting radish seedlings is not recommended. Their delicate roots are easily damaged, which can distort their shape and reduce quality.

Radishes are easy and fast-growing. Thin early and inter-crop them with slower-growing vegetables to save space. Plant every two weeks during the growing season for a continuous harvest.

Soil, Sun, Water, and Spacing

Soil:
Radishes prefer well-drained, fertile, loose soil with a pH between 6.0 and 7.0. Amend the soil with compost or well-rotted manure to improve fertility and structure and to help roots expand evenly.

Sun:
Full sun to partial shade is ideal for radishes. Aim for at least 4–6 hours of sunlight daily. In warmer weather, some afternoon shade can help keep roots from becoming hot and bitter.

Watering:
Keep the soil consistently moist but not waterlogged. Even moisture helps radish roots develop quickly without cracking. Mulching lightly can help regulate soil moisture and temperature.

Spacing:
Plant radish seeds about 1 inch apart in rows spaced roughly 6 inches apart. Once seedlings have a few true leaves, thin them to 2–3 inches apart so roots have room to size up.

Harvesting and Additional Tips

Harvesting:
Harvest radishes when they reach the desired size and before they become woody or pithy. This is typically around 20–30 days after planting, when roots are about 1–2 inches in diameter depending on the variety. Check frequently and harvest promptly for the best flavor and texture.

Additional Tips:

• Radishes grow best in well-drained, loose soil rich in organic matter. Compost improves soil quality and makes it easier for roots to swell.
• Avoid high-nitrogen fertilizers, which can encourage lush leaf growth at the expense of root development.
• Maintain consistent soil moisture during root development to prevent stress-induced cracking and uneven growth.
• Spicy, bitter flavor is often caused by hot weather and over-maturity. Harvest early during warm spells for the mildest taste.
• Use succession planting every 10–14 days during the cool season to keep radishes coming all fall and winter in Florida.

Fertilization, Care, and Problems

Fertilization (N–P–K Ratio):
Radishes benefit from fertilizers with lower nitrogen and higher phosphorus and potassium to support root development, such as 5-10-10 or 4-8-4.

When to Add:
Before Planting: Apply fertilizer and work it into the top 4–6 inches of soil before sowing seeds to support strong initial root growth.
Mid-Growing Season: For longer-season or winter radishes, a light side-dressing partway through the season can help maintain growth, but many fast spring radishes won’t need a second feeding.

Application Tips:

• Always follow the directions on the fertilizer package to avoid over-fertilization.
• Apply fertilizer evenly around the planting area and water thoroughly so nutrients move into the root zone.

Pests and Diseases that Affect Radishes in Florida:

• Flea Beetles: Small beetles that chew tiny “shot holes” in leaves. Heavy damage can slow growth.
• Root Maggots: Larvae that tunnel into roots, causing decay and making radishes inedible.
• Aphids: Small sap-sucking insects that cause leaf curling, yellowing, and can spread viruses.
• Cabbage Root Maggots: Fly larvae that burrow into roots, causing wilting and plant death.
• Downy Mildew: A disease that causes yellow patches on leaves with fuzzy grayish growth underneath.
• Clubroot: A soil-borne disease causing swollen, distorted roots and overall stunted plants.

Blog post on Natural Fertilizers

Natural Pest Control

Companion Plants and Plants to Avoid

Companion Plants:

Plants to Avoid Nearby: