Grow Guide to Radish

Raphanus sativus

Plant Description

Radishes are fast-growing root vegetables with vibrant red skin, crisp white interiors, and a peppery bite. Their leafy green tops are also edible and nutrient-rich. Available in many shapes and colors, radishes are one of the easiest vegetables to grow—making them ideal for new gardeners or kids.

They’re quick to harvest, thrive in cool weather, and double as a soil conditioner with their deep taproots loosening the soil for later crops.

Quick Facts

  • Sunlight: Full sun preferred; partial shade tolerated (especially in warmer climates).
  • Days to Sprout: 5–10 days.
  • Days to Harvest: 20–30 days (one of the fastest-growing vegetables).
  • Plant Spacing: 2–4 inches apart for round varieties; 4–6 inches for longer types.
  • Seeds per Hole: 2 seeds per hole; thin to the strongest seedling.
  • Plant Type: Annual.
  • Planting Depth: ½ inch deep.

Best Planting Locations

  • Garden Plots: Perfect for expansive growth, quick harvests, and succession planting every 2–3 weeks.
  • Raised Beds: Excellent drainage promotes uniform roots and easy harvesting.
  • Containers: Suitable for short-rooted varieties. Use at least 6 inches of depth with loose potting mix.
  • Interplanting: Tuck between slower-growing crops like carrots or squash for efficient use of space.

Getting Started

  1. Direct Sow Only: Radishes don’t transplant well. Sow seeds directly where they’ll grow.
  2. Soil Needs: Loose, well-drained soil enriched with compost. Avoid high-nitrogen soil or fresh manure which encourages leaf growth over roots.
  3. Thinning: Essential to prevent overcrowding and misshapen roots. Thin early, leaving 2–4 inches between plants.

Companion / Enemy Plants

Good Companions: Lettuce, spinach, cucumbers, peas, carrots, and nasturtiums.

Avoid Planting Near: Hyssop (can inhibit growth) and potatoes (can compete underground).

Attractants / Repellents

Attracts: Pollinators when left to flower. Also useful as a trap crop for flea beetles.

Repels: May confuse or deter some pests when interplanted with leafy greens or cucurbits.

When to Plant

  • Spring: Start 2–4 weeks before the last frost. Cool soil helps reduce bitterness and bolting.
  • Fall: Sow 6–8 weeks before first frost. Fall-grown radishes tend to be milder and less woody.

Maintenance

  • Watering: Keep soil evenly moist. Inconsistent watering causes splitting or woody texture.
  • Fertilizing: Use compost or a balanced organic fertilizer. Avoid high nitrogen products that promote leafy growth over roots.
  • Pest Control: Use row covers to deter flea beetles and leaf miners, especially during spring.

Harvest

  • Harvest when roots reach ~1 inch in diameter—usually 3–4 weeks after planting.
  • Don’t wait too long: overgrown radishes become pithy or woody. Check daily once near maturity.
  • Loosen soil and pull up gently by the base of the greens.

Uses

  • Fresh: Add crunch to salads, sandwiches, and tacos. Slice thin or serve whole with butter and salt.
  • Cooked: Roast, pickle, or sauté for a mellow, slightly sweet flavor.
  • Greens: Edible too—use in stir-fries, soups, or as a spicy sautéed side.

How to Store

  • Short Term: Remove greens and store roots in a sealed bag in the fridge. Keeps 1–2 weeks.
  • Long Term: Pickle for extended shelf life. Store in brine in sterilized jars in the fridge.
  • Greens: Use within 1–2 days or sauté immediately after harvest.