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When to Plant Nasturtium in Austin County, TX

Nasturtium (Tropaeolum majus) is a fast-growing annual with distinctive round, lily-pad leaves and bold trumpet-shaped blooms in warm oranges, reds, and yellows. Both the flowers and leaves are edible with a peppery watercress flavor. Planted near vegetables, nasturtiums act as a sacrifice trap-crop, luring aphids away from more valuable plants. They thrive in poor, dry soil — rich conditions produce lush foliage but few flowers.

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 Nasturtium during the growing season. Clay soil retains moisture well for Nasturtium, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Nasturtium root diseases.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Austin County, TX (Zone 9a) Year-round
274 days
Last Spring Frost February 28
274 growing days
First Fall Frost November 29

Austin County Soil Profile

Soil Type

Clay

Soil pH

6.8-8.1

Drainage

Well Drained

Monthly Watering Guide for Nasturtium

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

Month Nasturtium 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.

Nasturtium Planting Timeline — Austin County, TX

Nasturtium Planting Calendar

Activity When Date Range
Start Indoors January 31 Jan 31 – Feb 14
Transplant Outdoors February 7 Feb 7 – Feb 21
Direct Sow February 7 Feb 7 – Feb 28
Bloom April 4 Apr 4 – Oct 3

Plant 0.5" deep · 10" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

55–65 days

🧪 Soil pH

Needs 6–8 · Your soil: N/A

🗺️ USDA Zone

Zone 9a

📆 Growing Season

274 days in Austin County

Growing Tips for Austin County

Direct-sow large seeds 1/2 inch deep after last frost; soak seeds overnight to speed germination (7-10 days). Nasturtiums dislike root disturbance so direct sowing is strongly preferred. Avoid fertilizing — poor soil brings the best bloom. Trailing types can cover banks and climb trellises; dwarf types suit containers. In hot climates (zones 9+) plant in fall for winter/spring bloom as plants struggle in peak summer heat.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Nasturtium in Austin County, TX?

Austin County is in Zone 9a with an average last frost of February 28. Plan your Nasturtium 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 22-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: July 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.