SuNutri
SuNutri
Radishes
Beginner

Radishes

Raphanus sativus

Family: Brassicaceae

Radishes are the perfect beginner vegetable—fast-growing, easy to grow, and ready to harvest in as little as 25 days. These peppery roots add crunch and zing to salads. Beyond spring radishes, winter varieties offer larger roots that store for months.

Days to Harvest

22-70 days

Sun Needs

Full Sun to Partial Shade (4-6 hours)

Water Needs

moderate

Germination Temp

65°F optimal

Seed Starting

Start Indoors

0 weeks before last frost

Germination

3-7 days

Seed Depth

1/2 inch

Light to Germinate

No

💡 Tip: Always direct sow—radishes do not transplant well. Sow as soon as soil can be worked in spring.

Growing Conditions

Soil Type

Loose, well-draining soil

pH Range

6 - 7

Spacing

1-2 inches between plants, 6-12 inches between rows

Companion Plants
LettuceSpinachCarrotsBeansPeas

⚠️ Avoid planting near:

Hyssop
History & Nutrition

History

Radishes hold the distinction of being one of the earliest domesticated crops and among the first vegetables planted in space, a testament to their rapid growth and reliability that has made them garden favorites for over 4,000 years. Wild radishes likely originated in Southeast Asia, possibly China, and spread westward along ancient trade routes. By 2700 BCE, radishes were an established crop in ancient Egypt, where workers building the pyramids were reportedly paid in radishes, onions, and garlic. Herodotus, the Greek historian, described an inscription on the Great Pyramid of Giza listing the cost of these vegetable rations. The Greeks were so enamored with radishes that they made gold replicas to offer at the temple of Apollo at Delphi, while offering only silver beets and lead turnips. Roman agriculturalist Pliny the Elder catalogued numerous varieties including round, long, and mild types, noting that radishes from Germany could grow to forty pounds. The name "radish" derives from the Latin "radix" meaning root, which also gives us words like "radical" and "eradicate." Different cultures developed distinct varieties suited to their climates: the Japanese cultivated massive daikon radishes used fresh, pickled (takuan), and dried; Koreans made kkakdugi, cubed radish kimchi; and Europeans bred small, quick-maturing spring radishes. Black Spanish radishes, mentioned in European texts since the 16th century, became traditional winter storage vegetables. In Mexico, the Night of the Radishes (Noche de Rábanos) on December 23rd in Oaxaca features intricate carved radish sculptures, a tradition dating to 1897. Radishes were among the first crops grown in the American colonies at Plymouth and later became one of the first vegetables cultivated in the International Space Station's Veggie plant growth system, continuing their role as the ultimate beginner's crop—now extended to space agriculture.

Nutritional Benefits

  • Good source of Vitamin C
  • Contains fiber
  • Low in calories
Climate & Temperature

Optimal Growing Temp

50°F - 65°F

Spring radishes thrive in cool weather between 50-65°F. They bolt quickly in heat above 75°F. Winter radishes tolerate warmer conditions better but still prefer cool weather for best quality.

Survival Range

40°F - 75°F

Can survive these temperatures

hardy
cool Season

Frost Note: Spring radishes tolerate light frosts down to 28°F when young. Winter radishes are extremely cold-hardy and can tolerate hard frosts. Some winter varieties improve in flavor after frost.

Best USDA Zones

Zone 3Zone 4Zone 5Zone 6Zone 7Zone 8Zone 9

Humidity

50-70%

Radishes tolerate a wide range of humidity. In very humid conditions, watch for leaf diseases. Consistent soil moisture is more important than air humidity.

Plant Size & Growth

Height

6-12 inches

Spread

4-6 inches

Growth Habit

upright

annualRoot Depth: Spring radishes develop small taproots 1-2 inches deep. Winter radishes like daikon can grow 12-18 inches deep. Loose soil to 12 inches is ideal for all types.
Growth Stages

Germination

3-7 days

Radish seeds are among the fastest to germinate. Seedlings emerge in 3-7 days, often in just 3-4 days in warm soil. They push through soil with distinctive lobed seed leaves.

Seedling Stage

Duration: 1 week

True leaves: First true leaves appear within 7-10 days of germination

Transplant ready: Radishes do not transplant well - always direct sow. Thin seedlings when 1 inch tall to proper spacing.

Vegetative Growth

Duration: 2-4 weeks for spring types, 6-8 weeks for winter types

Radishes develop foliage while simultaneously growing the root. The root swells rapidly - spring radishes can be ready in just 25 days total. Consistent cool weather and moisture are critical.

Harvest Maturity

Timing: 22-30 days for spring radishes, 50-70 days for winter radishes

  • Root shoulders visible at soil line
  • Spring radishes ready at 1 inch diameter
  • Winter radishes ready at variety-specific size (often 2-6 inches)
  • Leaves are full and healthy green
Expected Yield

Per Plant

1 radish per plant (spring radishes 0.5-2 oz, winter radishes 8-16 oz)

Per Square Foot

16 spring radishes or 4-9 winter radishes per square foot depending on variety

Harvest Frequency

One-time harvest for spring radishes. Harvest promptly when ready to prevent pithy, woody texture.

Factors Affecting Yield

  • Timing - radishes must mature in cool weather or they become pithy and bitter
  • Moisture - consistent watering prevents cracking and strong, harsh flavor
  • Spacing - crowding produces small, malformed roots
  • Soil quality - loose soil allows proper root development
  • Variety - some are more heat-tolerant and slower to bolt
  • Harvest timing - overripe radishes become pithy and woody
Watering Guide

Seedling Stage

Keep soil consistently moist until germination - critical for rapid growth

Established Plants

0.5-1 inch per week, more in hot weather. Never let soil dry out.

Preferred Method

Drip irrigation or hand watering works well. Overhead watering is fine for radishes. Keep soil evenly moist from seed to harvest.

⚠️ Critical Watering Periods

  • Entire growth period - radishes grow so fast that every day matters

Pro Tips

  • Consistent moisture is the key to crisp, mild radishes
  • Mulch lightly to maintain even moisture
  • Never let soil dry out completely
  • Water more frequently in hot weather to prevent stress
Fertilizing Guide
light feederRecommended: Balanced 10-10-10 or lower nitrogen 5-10-10

Feeding Schedule

Soil Preparation

Compost worked into soil

Once before planting

During Growth

None needed for spring radishes

N/A

Winter Radishes

Light side-dress at 3-4 weeks

Once

Organic Options

CompostWell-aged manureBalanced organic fertilizer

Work compost into soil before planting. Spring radishes grow so fast they need little additional fertilizer. Winter radishes benefit from light feeding mid-season.

Container Growing
✓ Suitable for containers

Minimum Size

6 inches deep for spring radishes

Recommended Size

8-12 inches deep and 12+ inches wide for best results, 16 inches deep for winter radishes

Depth Required

Spring radishes need 6-8 inches, winter types like daikon need 12-16 inches

Best Varieties for Containers

Cherry BelleFrench BreakfastEaster Egg MixSparkler

Container Tips

  • Radishes are perfect for containers - fast and easy
  • Use any size container for spring radishes - even window boxes work
  • Thin to 1-2 inches apart for spring types
  • Keep soil consistently moist for crisp, mild roots
  • Great for teaching kids about gardening due to quick results
  • Succession plant every 7-10 days for continuous harvest
Succession Planting

Plant Every

Every 7-10 days for spring types

Sowings/Season

8-12 small plantings of spring radishes for continuous harvest

Duration

Early spring until temperatures warm, then resume in late summer for fall

Tips

  • Sow small amounts frequently rather than large amounts at once
  • Mark calendar for next sowing every week
  • Skip mid-summer in hot climates - radishes bolt in heat
  • Plant winter radishes in mid-summer for fall harvest
  • Interplant with slower crops as row markers
Frequently Asked Questions

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