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When to Plant Garlic in Karnes County, TX

Karnes County, Texas Zone 9a May

May to-do list for Karnes County, Texas

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

Avg. last frost February 26
Avg. first frost November 30
Soil temp (4") 59°F
Watering Low
Pest pressure High
Daylight 13.4 hrs

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Garlic is a pungent allium planted in fall and harvested the following summer. Hardneck varieties produce edible flower stalks (scapes) and are more cold-hardy.

Karnes County, Texas is in USDA Zone 9a. The average last spring frost is February 26 and the first fall frost is November 30, giving you a growing season of approximately 277 days.

At an elevation of 4,532 feet, Karnes County receives approximately 67.2 inches of rainfall annually with predominantly loam soil. Summer highs average 95°F, so Garlic may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Garlic root diseases.

Karnes County, TX (Zone 9a) Year-round
277 days
Last Spring Frost February 26
277 growing days
First Fall Frost November 30

Karnes County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (22 days to spare)
Transplant: Feb 14 🍅 Harvest: May 16 – Oct 31
Recommended (50%) ✓ Fits season (18 days to spare)
Transplant: Feb 26 🍅 Harvest: May 28 – Nov 12
Safe Start (90%) ✓ Fits season (14 days to spare)
Transplant: Mar 23 🍅 Harvest: Jun 22 – Dec 7

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 Karnes County

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

Soil pH

Your soil pH (6.3–7.8) overlaps with Garlic's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Garlic.

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Garlic.

How to Plant Garlic

1"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 6 weeks before your first frost date for a fall harvest.

Plant Water Budget

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

Monthly Watering Guide for Garlic

Garlic 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 Garlic Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 2.2" 2.6" 0" ✅ Rainfall sufficient
Mar 2.2" 4.6" 0" ✅ Rainfall sufficient
Apr 2.2" 6.3" 0" ✅ Rainfall sufficient
May 2.2" 8.6" 0" ✅ Rainfall sufficient
Jun 2.2" 11.7" 0" ✅ Rainfall sufficient
Jul 2.2" 9.1" 0" ✅ Rainfall sufficient
Aug 2.2" 8.7" 0" ✅ Rainfall sufficient
Sep 2.2" 6.7" 0" ✅ Rainfall sufficient
Oct 2.2" 3.9" 0" ✅ Rainfall sufficient
Nov 2.2" 2" 0.2" 💧 Light watering
Dec 1.5" 0" ❄️ Dormant

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

Garlic 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.

Garlic needs ~3,506 GDD — county provides 5,907 GDD Excellent fit

Garlic Planting Timeline — Karnes County, TX

Garlic Planting Calendar

Activity When Date Range
Fall Sowing October 19 Oct 19 – Nov 2

Plant 1" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June
July
August
September
October Fall Sowing
November Fall Sowing
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

90–240 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

277 days in Karnes County

Growing Tips for Garlic in Karnes County

Direct sow Garlic outdoors after February 26 in Karnes County when soil has warmed and frost danger has passed.

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

With 67" of annual rainfall in Karnes County, ensure good drainage for Garlic — excess moisture can promote root rot and fungal diseases.

General growing tips

Plant individual cloves pointed end up in fall, 6 weeks before ground freezes. Mulch heavily with straw. Harvest when lower leaves begin to brown but 5-6 green leaves remain.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans
  • Asparagus

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Garlic in Karnes County, TX?

Karnes County is in Zone 9a with an average last frost of February 26. Plan your Garlic planting based on this frost date — see the calendar above for exact timing.

What planting zone is Karnes County, TX?

Karnes County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 26 and first fall frost is November 30.

🌱

Your Karnes County Garden Planner — Free

A 24-page printable planner built for Karnes 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 Karnes 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.