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When to Plant Onion in Menard County, TX

Menard County, Texas Zone 8a May

Top priorities for Menard County, Texas gardeners in May

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Menard County, Texas.

Avg. last frost March 31
Avg. first frost November 9
Soil temp (4") 65°F
Watering Low
Pest pressure High
Daylight 13.6 hrs
  1. Time to start onion inside

    You're about 27 weeks out from your last frost — the perfect window to get these germinating indoors.

Before June arrives, get these ready
  • 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.

Menard County, Texas is in USDA Zone 8a. The average last spring frost is March 31 and the first fall frost is November 9, giving you a growing season of approximately 223 days.

At an elevation of 2,779 feet, Menard County receives approximately 56.7 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Onion during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Onion root diseases.

Menard County, TX (Zone 8a) Long season
223 days
Last Spring Frost March 31
223 growing days
First Fall Frost November 9
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Menard County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (81 days to spare)
Start indoors: Feb 14 Transplant: Mar 21 🍅 Harvest: Jun 20 – Aug 8
Recommended (50%) ✓ Fits season (83 days to spare)
Start indoors: Feb 24 Transplant: Mar 31 🍅 Harvest: Jun 30 – Aug 18
Safe Start (90%) ✓ Fits season (82 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: Jul 17 – Sep 4

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 Menard County

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

Soil pH

Your soil pH (6.4–7.5) overlaps with Onion's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help 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
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 1.5" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 4.3" 3.6" 0.7" 💧 Light watering
Apr 4.3" 5.9" 0" ✅ Rainfall sufficient
May 4.3" 7.4" 0" ✅ Rainfall sufficient
Jun 4.3" 10.8" 0" ✅ Rainfall sufficient
Jul 4.3" 6.6" 0" ✅ Rainfall sufficient
Aug 4.3" 7.1" 0" ✅ Rainfall sufficient
Sep 4.3" 4.7" 0" ✅ Rainfall sufficient
Oct 4.3" 3.7" 0.6" 💧 Light watering
Nov 4.3" 1.9" 2.4" 🚿 Regular watering
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Menard 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 ~1,916 GDD — county provides 4,069 GDD Excellent fit

Onion Planting Timeline — Menard County, TX

Onion Planting Calendar

Activity When Date Range
Start Indoors February 24 Feb 24 – Mar 10
Transplant Outdoors March 31 Mar 31 – Apr 14
Direct Sow March 17 Mar 17 – Apr 7
Harvest June 30 Jun 30 – Aug 18
Fall Sowing August 31 Aug 31 – Sep 14

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

223 days in Menard County

Growing Tips for Onion in Menard County

Direct sow Onion outdoors after March 31 in Menard County when soil has warmed and frost danger has passed.

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 Menard County, TX?

Menard County is in Zone 8a with an average last frost of March 31. Plan your Onion planting based on this frost date — see the calendar above for exact timing.

What planting zone is Menard County, TX?

Menard County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 31 and first fall frost is November 9.

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Your Menard County Garden Planner — Free

A 24-page printable planner built for Menard County (Zone 8a). 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 Menard 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.