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When to Plant Nasturtium in Irion County, TX

Irion County, Texas Zone 8a July

Top priorities for Irion County, Texas gardeners in July

Each item below is timed to Irion County, Texas's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 1
Avg. first frost November 7
Soil temp (4") 84°F
Watering Low
Pest pressure High
Daylight 13.8 hrs
  1. Collect nasturtium at their peak

    If you can't use it all right away, check the food-preservation section of your planner.

Before August arrives, get these ready
  • First harvests: nasturtium

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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.

Irion County, Texas is in USDA Zone 8a. The average last spring frost is April 1 and the first fall frost is November 7, giving you a growing season of approximately 220 days.

At an elevation of 1,818 feet, Irion County receives approximately 51.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 100°F, so Nasturtium may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Nasturtium will need more frequent watering and organic matter to retain nutrients. 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
Irion County, TX (Zone 8a) Long season
220 days
Last Spring Frost April 1
220 growing days
First Fall Frost November 7

Irion County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.6-8.6

Drainage

Well Drained

Nasturtium Planting Risk Windows

Early Start (70% safe) ✓ Fits season (18 days to spare)
Start indoors: Feb 21 Transplant: Mar 14 🌸 Bloom: May 9 – Oct 10
Recommended (50%) ✓ Fits season (17 days to spare)
Start indoors: Mar 4 Transplant: Mar 25 🌸 Bloom: May 20 – Oct 21
Safe Start (90%) ✓ Fits season (19 days to spare)
Start indoors: Mar 18 Transplant: Apr 8 🌸 Bloom: Jun 3 – Nov 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 Irion County

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

Soil pH

Your soil pH (7.6–8.6) is more alkaline than Nasturtium prefers (6.0–8.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is low (1.0%). Add 2-3 inches of compost before planting Nasturtium.

How to Plant Nasturtium

0.5"
Planting Depth
10"
Between Plants
12"
Between Rows

Succession Planting Nasturtium

4
successive plantings in your 220-day season

Sow every 6.3 weeks. Last sowing by Sep 03 to harvest before frost.

Nasturtium Water Budget

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

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

Monthly Watering Guide for Nasturtium

Nasturtium 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 Nasturtium Needs Rainfall You Supplement Action
Jan 3.8" 0" ❄️ Dormant
Feb 3.1" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 2.2" 1.8" 0.4" 💧 Light watering
May 2.2" 1.4" 0.8" 💧 Light watering
Jun 2.2" 1.7" 0.5" 💧 Light watering
Jul 2.2" 9.5" 0" ✅ Rainfall sufficient
Aug 2.2" 9.5" 0" ✅ Rainfall sufficient
Sep 2.2" 6.8" 0" ✅ Rainfall sufficient
Oct 2.2" 4.5" 0" ✅ Rainfall sufficient
Nov 2.2" 2.8" 0" ✅ Rainfall sufficient
Dec 3.7" 0" ❄️ Dormant

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

Nasturtium 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.

Nasturtium needs ~1,500 GDD — county provides 5,500 GDD Excellent fit

Nasturtium Planting Timeline — Irion County, TX

Nasturtium Planting Calendar

Activity When Date Range
Start Indoors March 4 Mar 4 – Mar 18
Transplant Outdoors March 25 Mar 25 – Apr 8
Direct Sow March 25 Mar 25 – Apr 15
Bloom May 20 May 20 – Oct 21

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

55–65 days

🧪 Soil pH

Needs 6–8 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 8a

📆 Growing Season

220 days in Irion County

Growing Tips for Nasturtium in Irion County

Direct sow Nasturtium outdoors after April 01 in Irion County when soil has warmed and frost danger has passed.

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

With summer highs reaching 100°F in Irion County, provide afternoon shade for Nasturtium and water deeply in the morning.

General growing tips

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 Irion County, TX?

Irion County is in Zone 8a with an average last frost of April 1. Plan your Nasturtium planting based on this frost date — see the calendar above for exact timing.

What planting zone is Irion County, TX?

Irion County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is April 1 and first fall frost is November 7.

🌱

Your Irion County Garden Planner — Free

A 22-page printable planner built for Irion 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 Irion 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.