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When to Plant Leeks in Duval County, TX

Duval County, Texas Zone 9b May

Your May gardening checklist

May is a pivotal month for Duval County, Texas gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost February 13
Avg. first frost December 9
Soil temp (4") 67°F
Watering Low
Pest pressure High
Daylight 13.4 hrs
  1. Collect leeks at their peak

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

A few tasks this May that'll pay off in June
  • 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.

Duval County, Texas is in USDA Zone 9b. The average last spring frost is February 13 and the first fall frost is December 9, giving you a growing season of approximately 299 days.

At an elevation of 4,259 feet, Duval County receives approximately 55.2 inches of rainfall annually with predominantly loam soil. Summer highs average 102°F, so Leeks may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Leeks root diseases.

Duval County, TX (Zone 9b) Year-round
299 days
Last Spring Frost February 13
299 growing days
First Fall Frost December 9

Duval County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (146 days to spare)
Start indoors: Dec 23 Transplant: Jan 20 🍅 Harvest: Apr 21 – Jul 7
Recommended (50%) ✓ Fits season (131 days to spare)
Start indoors: Jan 16 Transplant: Feb 13 🍅 Harvest: May 15 – Jul 31
Safe Start (90%) ✓ Fits season (119 days to spare)
Start indoors: Feb 8 Transplant: Mar 8 🍅 Harvest: Jun 7 – Aug 23

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 Duval County

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

Soil pH

Your soil pH (6.8–7.3) is more alkaline than Leeks prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Duval County is excellent for Leeks — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help 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
0.8″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 73 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 1.6" 0" ❄️ Dormant
Feb 3.5" 1.7" 1.8" 🚿 Regular watering
Mar 3.5" 4" 0" ✅ Rainfall sufficient
Apr 3.5" 5.3" 0" ✅ Rainfall sufficient
May 3.5" 8.7" 0" ✅ Rainfall sufficient
Jun 3.5" 8.4" 0" ✅ Rainfall sufficient
Jul 3.5" 6.8" 0" ✅ Rainfall sufficient
Aug 3.5" 6" 0" ✅ Rainfall sufficient
Sep 3.5" 5.7" 0" ✅ Rainfall sufficient
Oct 3.5" 3.6" 0" ✅ Rainfall sufficient
Nov 3.5" 1.9" 1.6" 💧 Light watering
Dec 3.5" 1.6" 1.9" 🚿 Regular watering

Water needs are for active growing months only (Feb–Dec in Duval 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 ~3,180 GDD — county provides 7,950 GDD Excellent fit

Leeks Planting Timeline — Duval County, TX

Leeks Planting Calendar

Activity When Date Range
Start Indoors January 16 Jan 16 – Jan 30
Transplant Outdoors February 13 Feb 13 – Feb 27
Direct Sow January 23 Jan 23 – Feb 13
Harvest May 15 May 15 – Jul 31
Fall Sowing October 14 Oct 14 – Oct 28

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

Month-by-Month Timeline

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

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_alkaline

🗺️ USDA Zone

Zone 9b

📆 Growing Season

299 days in Duval County

Growing Tips for Leeks in Duval County

Direct sow Leeks outdoors after February 13 in Duval County when soil has warmed and frost danger has passed.

With summer highs reaching 102°F in Duval 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 Duval County, TX?

Duval County is in Zone 9b with an average last frost of February 13. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.

What planting zone is Duval County, TX?

Duval County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 13 and first fall frost is December 9.

🌱

Your Duval County Garden Planner — Free

A 24-page printable planner built for Duval County (Zone 9b). 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 Duval County, TX. 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.