Watermelon Radish
Raphanus sativus
Family: Brassicaceae
Watermelon radishes are a stunning variety with pale green or white exterior that reveals a vibrant pink interior when sliced—resembling a watermelon. This mild winter radish is as beautiful as it is delicious.
Days to Harvest
55-65 days
Sun Needs
Full Sun to Partial Shade (4-6 hours)
moderate
Germination Temp
65°F optimal
Start Indoors
0 weeks before last frost
Germination
4-7 days
Seed Depth
1/2 inch
Light to Germinate
No
💡 Tip: Best planted in late summer for fall harvest. Spring plantings may bolt. The interior color develops best in cool weather.
Soil Type
Loose, well-draining soil
pH Range
6 - 7
Spacing
3-4 inches between plants, 12 inches between rows
⚠️ Avoid planting near:
History
Also known as "Beauty Heart" or "Shinrimei" radish, this Chinese heirloom has been cultivated for centuries. The dramatic interior color made it popular for decorative presentations in Asian cuisines.
Nutritional Benefits
- ✓Good source of Vitamin C
- ✓Low in calories
- ✓Contains fiber
Optimal Growing Temp
50°F - 65°F
Watermelon radish is a winter radish—best grown for fall harvest.
Survival Range
25°F - 75°F
Can survive these temperatures
Frost Note: Tolerates frost to 20°F. Frost intensifies pink color and sweetness.
Best USDA Zones
Humidity
50-70%
Moderate humidity is fine.
Height
12-15 inches
Spread
6-8 inches
Growth Habit
rosette
Germination
4-7 days
Quick germination.
Seedling Stage
Duration: 2-3 weeks
True leaves: Rough leaves develop
Transplant ready: Direct sow.
Vegetative Growth
Duration: 8-10 weeks
Pink interior color develops as roots mature.
Harvest Maturity
Timing: 55-60 days
- Shoulders 3-4 inches diameter
- Firm when pressed
- Pink color visible when sliced
Per Plant
1 root (8-16 oz)
Per Square Foot
4 radishes (6-inch spacing)
Harvest Frequency
Single harvest
Factors Affecting Yield
- •Fall planting
- •Consistent moisture
- •Frost exposure
Seedling Stage
Keep moist
Established Plants
1-1.5 inches per week
During Fruiting
Consistent moisture for best color
Preferred Method
Drip irrigation.
⚠️ Critical Watering Periods
- • Root development
Pro Tips
- Consistent moisture produces best color and texture
Feeding Schedule
Soil prep
Compost
Once
Organic Options
Work compost into soil before planting.
Minimum Size
10 inches deep
Recommended Size
12+ inches deep
Depth Required
10 inches minimum
Container Tips
- Deep container for full root development
