How to grow daikon radish
Family Brassicaceae. Hardy to USDA hardiness zone 3a+ (U.S. Department of Agriculture). Full sun. Ready in 50-70 days.
Sun
Full sun
Spacing
4-6 in
Days to harvest
50-70 days
Hardiness
Zone 3a+
What growers actually recorded
Loading zone 7b results…
When to plant daikon radish
- Direct sow: ~-8 weeks after last frost.
Companion plants for daikon radish
Plant with: Carrot, Lettuce, Pea.
Avoid near: Hyssop.
Common pests & problems
Flea beetle, root maggot.
Feeding & fertilizer
N-P-K ratio: High N (10-5-5): heavy feeders
Organic options: Aged manure or compost worked in deep · Blood meal or feather meal side-dress at 3 wks · Fish emulsion every 2 wks
When to feed: Feed heavily every 2-3 weeks. Brassicas want steady nitrogen for tight heads.
Watch for: Pale/yellow leaves = needs N. Loose heads = feed harder next round.
N = nitrogen (leaves), P = phosphorus (roots and flowers), K = potassium (fruit and disease resistance). How to read a fertilizer label →
Grower's tip
Best sown in late summer for fall harvest: spring-sown daikon bolts fast once heat arrives.
When to plant daikon radish in your zone
Free month-by-month sowing and transplanting lists, built from frost dates for your USDA (United States Department of Agriculture) hardiness zone.
Soil & water for daikon radish
Soil & pH
6.5-7.5: near neutral (raises club-root resistance)
Fertile loam with strong drainage. Firm soil beats fluffy for heading brassicas.
Compost 2 in + 1 cup of alfalfa or feather meal per 10 sq ft. Lime if pH is under 6.5. It also blocks club-root.
Watering
1-1.5 in / week, consistent
Ground-level drip. Uneven water during heading = split heads or bolting.
Lift an edge of the row and check soil at 3 inches. If it clings in a damp ball, hold off. If it crumbles, water until the top 6 inches are evenly moist.
Knowing when to harvest
- Shoulders visible at the soil surface, 1.5-2 in across for most varieties; full length varies 8-18 in by type.
- Loosen soil with a fork before pulling; daikon roots are long and brittle.
- Harvest before a hard freeze; roots left too long in warm soil turn pithy.
Storing & keeping
Trim tops, store unwashed in damp sand or a perforated bag at 32-40°F, 90-95% humidity for 2-4 months. Also widely fermented (takuan, kimchi) for long-term preservation.
What to expect
Per plant: 1 root, 1-3 lb
Per sq ft: 2-4 roots per sq ft
Troubleshooting daikon radish
Forked or split roots
Likely cause: Rocky or compacted soil, or fresh manure
What to do: Deep-till the bed 12-18 in and use only finished compost.
Pithy, hollow centers
Likely cause: Overmaturity or heat stress during growth
What to do: Harvest promptly at target size and grow as a fall crop in warm climates.
Varieties worth growing
Minowase
Long, classic Japanese type, 18+ in, mild flavor.
April Cross
Fast-maturing, bolt-resistant, suited to spring sowing where daikon is normally fall-only.
Watermelon Radish (Misato Rose)
Green skin with a rose-pink interior, sweeter and milder than standard daikon.
Growing daikon radish in containers
18+ in deep container for long types; choose shorter, round daikon varieties for standard pots.
Nutrition
Sulforaphane, glucosinolates, vitamin K, calcium. Brassicas are the vegetable powerhouse.
Common questions
Why does daikon need deep, loose soil more than most radishes?
Standard daikon types grow 12-18 in long, so any compaction, rock, or clay layer forces the root to fork or stall short.
Can I grow daikon in spring?
Most varieties bolt quickly in spring's lengthening daylight; fall sowing is standard, though a few bolt-resistant varieties are bred for spring planting.
Where these numbers come from
- USDA Plant Hardiness Zone Map (2023 revision). Zone assignment and the 30-year normals behind every cold-hardiness figure.
- NOAA NCEI 1991-2020 Climate Normals. Frost dates, growing-season length, and the probability bands on both.
- Cornell, UMN, and UC Davis Cooperative Extension crop guides. Spacing, days to maturity, soil pH targets, and per-plant yield ranges.
- USDA FSIS / FDA Produce Safety guidance. Wash, cure, and cold-storage handling numbers.
Ranges are regional guidance, not a promise for your yard. Your own logged results always override the published range.