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When to Plant Leeks in Union County, FL

Union County, Florida Zone 9a May

May to-do list for Union County, Florida

A quick May briefing for Union County, Florida gardeners — what's urgent, what's next, and what can wait.

Avg. last frost March 1
Avg. first frost November 27
Soil temp (4") 79°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Collect leeks at their peak

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Coming up in June — start thinking about
  • First harvests: leeks

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Leeks are a mild, sweet allium that produces long white shanks. They are more refined than onions and are a key ingredient in soups, stews, and gratins.

Union County, Florida is in USDA Zone 9a. The average last spring frost is March 1 and the first fall frost is November 27, giving you a growing season of approximately 271 days.

At an elevation of 360 feet, Union County receives approximately 60.6 inches of rainfall annually with predominantly sand soil. Summer highs average 96°F, so Leeks may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Leeks will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Leeks root diseases.

Union County, FL (Zone 9a) Year-round
271 days
Last Spring Frost March 1
271 growing days
First Fall Frost November 27
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Union County Soil Profile

Soil Type

Sand

Soil pH

5.2-6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (107 days to spare)
Start indoors: Jan 17 Transplant: Feb 14 🍅 Harvest: May 16 – Aug 1
Recommended (50%) ✓ Fits season (103 days to spare)
Start indoors: Feb 1 Transplant: Mar 1 🍅 Harvest: May 31 – Aug 16
Safe Start (90%) ✓ Fits season (101 days to spare)
Start indoors: Feb 26 Transplant: Mar 26 🍅 Harvest: Jun 25 – Sep 10

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 Union County

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

Soil pH

Your soil pH (5.2–6.0) is more acidic than Leeks prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Leeks.

Organic Matter

Organic matter is low (1.3%). Add 2-3 inches of compost before planting Leeks.

How to Plant Leeks

1"
Planting Depth
15"
Between Plants
24"
Between Rows

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

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 243 gal / 100 sq ft

Monthly Watering Guide for Leeks

Leeks needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Leeks Needs Rainfall You Supplement Action
Jan 3.1" 0" ❄️ Dormant
Feb 2.7" 0" ❄️ Dormant
Mar 3.5" 3.5" 0" ✅ Rainfall sufficient
Apr 3.5" 2.8" 0.7" 💧 Light watering
May 3.5" 4.4" 0" ✅ Rainfall sufficient
Jun 3.5" 8.1" 0" ✅ Rainfall sufficient
Jul 3.5" 10" 0" ✅ Rainfall sufficient
Aug 3.5" 9" 0" ✅ Rainfall sufficient
Sep 3.5" 7.2" 0" ✅ Rainfall sufficient
Oct 3.5" 4.5" 0" ✅ Rainfall sufficient
Nov 3.5" 2.7" 0.8" 💧 Light watering
Dec 2.5" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Union County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Leeks 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" — every day above 50°F 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.

Leeks needs ~2,640 GDD — county provides 5,962 GDD Excellent fit

Leeks Planting Timeline — Union County, FL

Leeks Planting Calendar

Activity When Date Range
Start Indoors February 1 Feb 1 – Feb 15
Transplant Outdoors March 1 Mar 1 – Mar 15
Direct Sow February 8 Feb 8 – Mar 1
Harvest May 31 May 31 – Aug 16
Fall Sowing October 2 Oct 2 – Oct 16

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors Direct Sow
March Transplant Outdoors Direct Sow
April
May Harvest
June Harvest
July Harvest
August Harvest
September
October Fall Sowing
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Only during dry spells

📅 Days to Maturity

90–150 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

271 days in Union County

Growing Tips for Leeks in Union County

Direct sow Leeks outdoors after March 01 in Union County when soil has warmed and frost danger has passed.

Sandy soil in Union County dries quickly — mulch Leeks with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 96°F in Union County, provide afternoon shade for Leeks and water deeply in the morning.

Common pests for Leeks in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 10-12 weeks before last frost. Transplant into trenches and hill soil around stems as they grow to increase the white portion. Harvest as needed.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Leeks in Union County, FL?

Union County is in Zone 9a with an average last frost of March 1. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.

What planting zone is Union County, FL?

Union County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is March 1 and first fall frost is November 27.

🌱

Your Union County Garden Planner — Free

A 24-page printable planner built for Union County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Union County, FL. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.