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When to Plant Radish in St. Johns County, FL

Radishes are one of the fastest-growing vegetables, with some varieties ready in under a month. They come in round, elongated, and large winter types.

St. Johns County, Florida is in USDA Zone 9a. The average last spring frost is February 9 and the first fall frost is December 2, giving you a growing season of approximately 296 days.

At an elevation of 57 feet, St. Johns County receives approximately 51.1 inches of rainfall annually with predominantly sand soil. Summer highs average 99ยฐF, so Radish may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Radish will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Radish root diseases.

St. Johns County, FL (Zone 9a) Year-round
296 days
Last Spring Frost February 9
296 growing days
First Fall Frost December 2

St. Johns County Soil Profile

Soil Type

Sand

Soil pH

4.9-6.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (258 days to spare)
Transplant: Jan 25 🍅 Harvest: Feb 22 – Mar 15
Recommended (50%) ✓ Fits season (247 days to spare)
Transplant: Feb 9 🍅 Harvest: Mar 9 – Mar 30
Safe Start (90%) ✓ Fits season (238 days to spare)
Transplant: Mar 11 🍅 Harvest: Apr 8 – Apr 29

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 880 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Radish needs ~691 GDD — county provides 7,202 GDD Excellent fit

Radish Planting Timeline โ€” St. Johns County, FL

Radish Planting Calendar

Activity When Date Range
Direct Sow January 19 Jan 19 โ€“ Feb 9
Fall Sowing October 7 Oct 7 โ€“ Oct 21
Harvest February 16 Feb 16 โ€“ Mar 9

Plant 0.5" deep ยท 2" apart ยท Rows 6" apart

Month-by-Month Timeline

MonthActivities
January Direct Sow
February Direct Sow Harvest
March Harvest
April โ€”
May โ€”
June โ€”
July โ€”
August โ€”
September โ€”
October Fall Sowing
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

22โ€“35 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 9a

Growing Season

296 days

Growing Tips for St. Johns County

Direct sow every 1-2 weeks for continuous harvest. Do not transplant. Harvest spring radishes promptly to prevent them from becoming pithy and hot.

Companion Planting

Good Companions

Avoid Planting Near

  • Hyssop

Level Up Your Garden

Frequently Asked Questions

When should I plant Radish in St. Johns County, FL?

St. Johns County is in Zone 9a with an average last frost of February 9. Plan your Radish planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is St. Johns County, FL?

St. Johns County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is February 9 and first fall frost is December 2.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help St. Johns County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for St. Johns County, FL. Local conditions may vary. Last updated: April 2026.