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When to Plant Onion in Val Verde County, TX

Val Verde County, Texas Zone 8b May

This month in Val Verde County, Texas

A quick May briefing for Val Verde County, Texas gardeners — what's urgent, what's next, and what can wait.

Avg. last frost February 17
Avg. first frost December 7
Soil temp (4") 62°F
Watering Critical
Pest pressure High
Daylight 13.5 hrs
  1. It's harvest week for onion

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

Looking ahead to June
  • First harvests: onion

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Onions are a fundamental kitchen staple available in yellow, white, and red varieties. Choose long-day, short-day, or intermediate types based on your latitude.

Val Verde County, Texas is in USDA Zone 8b. The average last spring frost is February 17 and the first fall frost is December 7, giving you a growing season of approximately 293 days.

At an elevation of 3,979 feet, Val Verde County receives approximately 53.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 98°F, so Onion may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Onion will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Onion root diseases.

Val Verde County, TX (Zone 8b) Year-round
293 days
Last Spring Frost February 17
293 growing days
First Fall Frost December 7

Val Verde County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.7-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (152 days to spare)
Start indoors: Jan 8 Transplant: Feb 12 🍅 Harvest: May 14 – Jul 2
Recommended (50%) ✓ Fits season (153 days to spare)
Start indoors: Jan 13 Transplant: Feb 17 🍅 Harvest: May 19 – Jul 7
Safe Start (90%) ✓ Fits season (147 days to spare)
Start indoors: Feb 2 Transplant: Mar 9 🍅 Harvest: Jun 8 – Jul 27

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 Val Verde County

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

Soil pH

Your soil pH (7.7–8.1) is more alkaline than Onion prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is low (0.9%). Add 2-3 inches of compost before planting Onion.

How to Plant Onion

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 758 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Onion

Onion needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Onion Needs Rainfall You Supplement Action
Jan 3.8" 0" ❄️ Dormant
Feb 4.3" 3.1" 1.2" 💧 Light watering
Mar 4.3" 2.8" 1.5" 💧 Light watering
Apr 4.3" 1.7" 2.6" 🚿 Regular watering
May 4.3" 1.1" 3.2" 🚿 Regular watering
Jun 4.3" 1.7" 2.6" 🚿 Regular watering
Jul 4.3" 9.6" 0" ✅ Rainfall sufficient
Aug 4.3" 11.5" 0" ✅ Rainfall sufficient
Sep 4.3" 6.2" 0" ✅ Rainfall sufficient
Oct 4.3" 4.3" 0" ✅ Rainfall sufficient
Nov 4.3" 3.3" 1" 💧 Light watering
Dec 4.3" 4" 0.3" 💧 Light watering

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

Onion 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.

Onion needs ~2,468 GDD — county provides 6,909 GDD Excellent fit

Onion Planting Timeline — Val Verde County, TX

Onion Planting Calendar

Activity When Date Range
Start Indoors January 13 Jan 13 – Jan 27
Transplant Outdoors February 17 Feb 17 – Mar 3
Direct Sow February 3 Feb 3 – Feb 24
Harvest May 19 May 19 – Jul 7
Fall Sowing September 28 Sep 28 – Oct 12

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 8b

📆 Growing Season

293 days in Val Verde County

Growing Tips for Onion in Val Verde County

Direct sow Onion outdoors after February 17 in Val Verde County when soil has warmed and frost danger has passed.

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

With summer highs reaching 98°F in Val Verde County, provide afternoon shade for Onion and water deeply in the morning.

Common pests for Onion 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 8-10 weeks before transplanting. Match day-length type to your latitude. Stop watering when tops begin to fall over and cure bulbs for 2-3 weeks before storage.

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 Onion in Val Verde County, TX?

Val Verde County is in Zone 8b with an average last frost of February 17. Plan your Onion planting based on this frost date — see the calendar above for exact timing.

What planting zone is Val Verde County, TX?

Val Verde County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is February 17 and first fall frost is December 7.

🌱

Your Val Verde County Garden Planner — Free

A 24-page printable planner built for Val Verde County (Zone 8b). 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 Val Verde 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.