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When to Plant Scallions in Austin County, TX

Austin County, Texas Zone 9a May

May in Austin County, Texas — your action list

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

Avg. last frost February 28
Avg. first frost November 29
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Start harvesting scallions

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

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Scallions (green onions) are mild-flavored alliums harvested for their slender green tops and white bases. They are quick-growing and perfect for succession planting.

Austin County, Texas is in USDA Zone 9a. The average last spring frost is February 28 and the first fall frost is November 29, giving you a growing season of approximately 274 days.

At an elevation of 350 feet, Austin County receives approximately 68.9 inches of rainfall annually with predominantly clay soil. Summer highs average 90°F, providing good warmth for Scallions during the growing season. Clay soil retains moisture well for Scallions, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Scallions root diseases.

Austin County, TX (Zone 9a) Year-round
274 days
Last Spring Frost February 28
274 growing days
First Fall Frost November 29
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Austin County Soil Profile

Soil Type

Clay

Soil pH

6.8-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (191 days to spare)
Start indoors: Jan 16 Transplant: Feb 13 🍅 Harvest: Apr 10 – May 8
Recommended (50%) ✓ Fits season (190 days to spare)
Start indoors: Jan 31 Transplant: Feb 28 🍅 Harvest: Apr 25 – May 23
Safe Start (90%) ✓ Fits season (190 days to spare)
Start indoors: Feb 22 Transplant: Mar 22 🍅 Harvest: May 17 – Jun 14

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 Austin County

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

Soil pH

Your soil pH (6.8–8.1) is more alkaline than Scallions prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Heavy clay soil (41% clay) in Austin County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Organic Matter

Organic matter is moderate (3.2%). Annual compost additions will help Scallions.

How to Plant Scallions

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

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

Succession Planting Scallions

6
successive plantings in your 274-day season

Sow every 5.7 weeks. Last sowing by Sep 20 to harvest before frost.

For a dedicated fall crop, sow by Oct 04.

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
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Scallions

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

Month Scallions Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 4.3" 2.4" 1.9" 💧 Light watering
Mar 4.3" 4.3" 0" ✅ Rainfall sufficient
Apr 4.3" 7.2" 0" ✅ Rainfall sufficient
May 4.3" 9.6" 0" ✅ Rainfall sufficient
Jun 4.3" 11.9" 0" ✅ Rainfall sufficient
Jul 4.3" 8.5" 0" ✅ Rainfall sufficient
Aug 4.3" 9.2" 0" ✅ Rainfall sufficient
Sep 4.3" 5.7" 0" ✅ Rainfall sufficient
Oct 4.3" 4.6" 0" ✅ Rainfall sufficient
Nov 4.3" 2.2" 2.1" 💧 Light watering
Dec 1.8" 0" ❄️ Dormant

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

Scallions 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.

Scallions needs ~1,050 GDD — county provides 4,812 GDD Excellent fit

Scallions Planting Timeline — Austin County, TX

Scallions Planting Calendar

Activity When Date Range
Start Indoors January 31 Jan 31 – Feb 14
Transplant Outdoors February 28 Feb 28 – Mar 14
Direct Sow February 7 Feb 7 – Feb 28
Harvest April 25 Apr 25 – May 23
Fall Sowing October 4 Oct 4 – Oct 18

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9a

📆 Growing Season

274 days in Austin County

Growing Tips for Scallions in Austin County

Direct sow Scallions outdoors after February 28 in Austin County when soil has warmed and frost danger has passed.

With Austin County's clay soil (41% clay), work in 3-4 inches of compost before planting Scallions. Avoid tilling when soil is wet to prevent compaction.

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

General growing tips

Direct sow every 3 weeks for continuous harvest. Thin to 1 inch apart or grow in clusters. Harvest when pencil-thick by pulling or cutting at soil level.

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 Scallions in Austin County, TX?

Austin County is in Zone 9a with an average last frost of February 28. Plan your Scallions planting based on this frost date — see the calendar above for exact timing.

What planting zone is Austin County, TX?

Austin County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 28 and first fall frost is November 29.

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Your Austin County Garden Planner — Free

A 24-page printable planner built for Austin 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 Austin 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.