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When to Plant Radish in Pinellas 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.

Pinellas County, Florida is in USDA Zone 9b. The average last spring frost is January 25 and the first fall frost is December 16, giving you a growing season of approximately 325 days.

At an elevation of 246 feet, Pinellas County receives approximately 58.1 inches of rainfall annually with predominantly sand soil. Summer highs average 102ยฐF, 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.

Pinellas County, FL (Zone 9b) Year-round
325 days
Last Spring Frost January 25
325 growing days
First Fall Frost December 16

Pinellas County Soil Profile

Soil Type

Sand

Soil pH

5.1-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (276 days to spare)
Transplant: Jan 19 🍅 Harvest: Feb 16 – Mar 9
Recommended (50%) ✓ Fits season (276 days to spare)
Transplant: Jan 25 🍅 Harvest: Feb 22 – Mar 15
Safe Start (90%) ✓ Fits season (250 days to spare)
Transplant: Feb 28 🍅 Harvest: Mar 28 – Apr 18

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.

Soil Compatibility in Pinellas County

How your county's soil matches Radish's growing requirements.

Soil pH

Your soil pH (5.1โ€“6.2) is more acidic than Radish prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Pinellas County warms quickly in spring but drains fast. Radish will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Radish.

Organic Matter

Organic matter is low (1.5%). Add 2-3 inches of compost before planting Radish.

How to Plant Radish

0.5"
Planting Depth
2"
Between Plants
6"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Radish

18
successive plantings in your 325-day season

Sow every 2.4 weeks. Last sowing by Nov 11 to harvest before frost.

For a dedicated fall crop, sow by Oct 21.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Radish

Radish needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Radish Needs Rainfall You Supplement Action
Jan 2.2" 2.9" 0" โœ… Rainfall sufficient
Feb 2.2" 3.2" 0" โœ… Rainfall sufficient
Mar 2.2" 3.7" 0" โœ… Rainfall sufficient
Apr 2.2" 2.4" 0" โœ… Rainfall sufficient
May 2.2" 3.6" 0" โœ… Rainfall sufficient
Jun 2.2" 7.6" 0" โœ… Rainfall sufficient
Jul 2.2" 8.5" 0" โœ… Rainfall sufficient
Aug 2.2" 8.7" 0" โœ… Rainfall sufficient
Sep 2.2" 7.1" 0" โœ… Rainfall sufficient
Oct 2.2" 5.3" 0" โœ… Rainfall sufficient
Nov 2.2" 2.5" 0" โœ… Rainfall sufficient
Dec 2.2" 2.6" 0" โœ… Rainfall sufficient

Water needs are for active growing months only (Janโ€“Dec in Pinellas County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Radish Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Radish needs ~755 GDD — county provides 8,639 GDD Excellent fit

Radish Planting Timeline โ€” Pinellas County, FL

Radish Planting Calendar

Activity When Date Range
Direct Sow January 4 Jan 4 โ€“ Jan 25
Harvest February 1 Feb 1 โ€“ Feb 22
Fall Sowing October 21 Oct 21 โ€“ Nov 4

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

22โ€“35 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 9b

๐Ÿ“† Growing Season

325 days in Pinellas County

Growing Tips for Radish in Pinellas County

Direct sow Radish outdoors after January 25 in Pinellas County when soil has warmed and frost danger has passed.

Sandy soil in Pinellas County dries quickly โ€” mulch Radish with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Summer highs in Pinellas County reach 102ยฐF โ€” grow Radish as a spring or fall crop. Use shade cloth if planting in summer.

Your generous 326.0-day season in Pinellas County allows multiple plantings of Radish. Sow every 11.0 days for continuous harvest.

Common pests for Radish in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Radish in Pinellas County, FL?

Pinellas County is in Zone 9b with an average last frost of January 25. Plan your Radish planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Pinellas County, FL?

Pinellas County, Florida is in USDA Hardiness Zone 9b. The average last spring frost is January 25 and first fall frost is December 16.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Pinellas County gardeners in Zone 9b 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 Pinellas County, FL. Local conditions may vary. Last updated: April 2026.