← Plant Guides

How to Grow Icicle Radish

Wikimedia Commons

Icicle Radish

Raphanus sativus var. longipinnatus

vegetable

Icicle radish is a long, slender white radish with a crisp, mild flavor and tender texture. It matures faster than most root vegetables and can be harvested at various sizes depending on preference. This heirloom variety is excellent for spring and fall gardens.

Looking for a specific variety?

Icicle Breakfast White Icicle Long White French Breakfast Candela

When should you plant Icicle Radish in your zone?

Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.

Get my Icicle Radish timeline →

Example Icicle Radish timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Icicle Radish

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Icicle Radish

    Around May 12

    ≈ 25 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Icicle Radish dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun, 6+ hours daily; tolerates partial shade
💧
Water: Keep soil consistently moist but not waterlogged; water 1 inch per week. Irregular watering causes splits and pithy texture. Maintain even moisture throughout growth.
📏
Spacing: 2 inches
📅
Days to maturity: 25-30 days
🌱
Planting depth: 0.5 inches

Soil

Type: Well-draining, loose loamy soil free of rocks and clods
pH: 6.0-7.0
Amendments:
Compost or aged manure for organic matter Sand to improve drainage if soil is heavy Avoid fresh nitrogen fertilizer (promotes forked roots)

Growing Zones

Find your zone →

Grows well in zones 2-10; prefers cool seasons, so best in spring and fall in warmer climates

2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a 10b

Sign up free to see if Icicle Radish grows in your zone — and get a personalized planting timeline.

Get my Icicle Radish timeline →

Growth Stages

1

Germination

1-2 weeks

Seeds sprout within 3-7 days. Tiny seedlings emerge with cotyledons (seed leaves).

Keep soil moist but not soggy. Provide consistent warmth (60-70°F ideal). Thin seedlings to proper spacing once true leaves appear.

2

Early Growth

1-2 weeks

True leaves develop; seedlings establish root systems. Small white shoulders may appear at soil surface.

Thin to 2-inch spacing if not done earlier. Water consistently. Keep weed-free to reduce competition. Mulch lightly to retain moisture.

3

Root Development

1-2 weeks

Radishes elongate underground, becoming pencil-thin. Top growth is modest; most energy goes to root expansion.

Maintain even soil moisture. Do not overwater or roots become pithy. Side-dress with compost if needed. Continue weeding.

4

Maturity

Ready for harvest

Radishes reach 4-6 inches long and reach full diameter (0.5-0.75 inches). Roots are crisp and white with mild flavor.

Check size by gently uncovering shoulder of radish. Harvest promptly when ready to avoid becoming pithy or hollow. Do not over-mature.

Companion Planting

Plan your garden →

Plant with:

Lettuce Spinach Carrot Pea Cucumber Chard Beet Cabbage

Avoid planting near:

Hyssop Fennel Kohlrabi (excessive competition for nutrients)

Common Pests

  • Use row covers on young plants, spray with neem oil, dust with diatomaceous earth, or plant trap crops like nasturtium

  • Use row covers or fine mesh, apply beneficial nematodes to soil, or use collars around base of plant

  • Rotate crops, remove debris, use beneficial nematodes, trap with potato or carrot baits

  • and

    Hand-pick, use beer traps, apply copper barriers, encourage predators like ground beetles

Uses

🍳

Fresh eating and salads

Culinary

Icicle radishes are prized for their crisp, mildly peppery flavor and tender white flesh. They are excellent sliced fresh in salads, as a crudités snack, or added to sandwiches for crunch. [source]

🍳

Roasting and cooking

Culinary

Unlike small round radishes, Icicle radishes are sturdy enough for roasting, braising, or stir-frying. Roasting mellows their peppery bite and brings out a subtle sweetness. [source]

🏠

Edible greens

Household

Radish greens are nutrient-dense and edible; use them in salads, smoothies, or cooked greens. They have a slightly peppery flavor similar to the roots. [source]

💊

Digestive and nutritional support

Medicinal

Radishes are rich in vitamin C, fiber, and glucosinolates (compounds with potential anti-inflammatory properties). Traditionally used to support digestion and liver function. [source]

🦋

Beneficial insect flowers

Wildlife

If allowed to bolt and flower, radish plants produce delicate white flowers that attract pollinators and beneficial insects like bees and hoverflies. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Harvest when radishes are 4-6 inches long and about pencil-thick (0.5-0.75 inches diameter). Check size by gently uncovering soil around shoulder. Harvest promptly to avoid pithy, hollow, or woody texture. Can eat radishes raw, sliced in salads, roasted, or cooked. Store in refrigerator in plastic bag for up to 2 weeks. Remove greens before storing to extend life.

Fun Facts

  • 🌱 Icicle radishes are among the fastest-growing vegetables, maturing in just 25-30 days from seed to harvest—making them perfect for impatient gardeners and teaching children about plant growth.
  • 🌱 The name 'Icicle' refers to their long, thin shape resembling an icicle, and they are sometimes called 'Japanese radishes' or 'Daikon long white' varieties, though true daikon are larger and slower-growing.
  • 🌱 Unlike most radishes that decline in quality quickly, Icicle radishes stay crisp and non-pithy for a longer period if kept consistently moist, allowing for extended harvests.

Gardening Terms

New to gardening? Learn about terms used in this guide:

Compost Full Sun Heirloom Mulch Partial Shade True Leaves
Shop Icicle Radish plants and related plants at Plant Addicts →

Join 30,000 gardeners planning their gardens with LizPlants.

Get your personalized Icicle Radish planting timeline

Tell us your zip code and we'll calculate exactly when to start Icicle Radish seeds, transplant seedlings, and harvest — based on your USDA zone and local frost dates. Includes calendar reminders and printable task lists. Free to start.

Get my Icicle Radish timeline →