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When to Plant Nasturtium in Waller County, TX

Waller County, Texas Zone 9a June

This month in Waller County, Texas

We've pulled the most time-sensitive tasks for Waller County, Texas this June and put them front and centre. Tackle them in order.

Avg. last frost February 19
Avg. first frost December 4
Soil temp (4") 81°F
Watering Low
Pest pressure High
Daylight 13.9 hrs
  1. Collect nasturtium at their peak

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

Coming up in July — start thinking about
  • 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.

Waller County, Texas is in USDA Zone 9a. The average last spring frost is February 19 and the first fall frost is December 4, giving you a growing season of approximately 288 days.

At an elevation of 376 feet, Waller County receives approximately 64.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 95°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
Waller County, TX (Zone 9a) Year-round
288 days
Last Spring Frost February 19
288 growing days
First Fall Frost December 4

Waller County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.6-6.2

Drainage

Well Drained

Nasturtium Planting Risk Windows

Early Start (70% safe) ✓ Fits season (69 days to spare)
Start indoors: Jan 14 Transplant: Jan 21 🌸 Bloom: Mar 18 – Sep 16
Recommended (50%) ✓ Fits season (71 days to spare)
Start indoors: Jan 22 Transplant: Jan 29 🌸 Bloom: Mar 26 – Sep 24
Safe Start (90%) ✓ Fits season (70 days to spare)
Start indoors: Feb 9 Transplant: Feb 16 🌸 Bloom: Apr 13 – Oct 12

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 Waller County

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

Soil pH

Your soil pH (5.6–6.2) is more acidic than Nasturtium prefers (6.0–8.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Waller 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 moderate (2.0%). Annual compost additions will help Nasturtium.

How to Plant Nasturtium

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

Succession Planting Nasturtium

6
successive plantings in your 288-day season

Sow every 6.3 weeks. Last sowing by Sep 30 to harvest before frost.

Nasturtium Water Budget

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

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 1.7" 0" ❄️ Dormant
Feb 2.2" 2.4" 0" ✅ Rainfall sufficient
Mar 2.2" 4.6" 0" ✅ Rainfall sufficient
Apr 2.2" 7.3" 0" ✅ Rainfall sufficient
May 2.2" 8.9" 0" ✅ Rainfall sufficient
Jun 2.2" 9.1" 0" ✅ Rainfall sufficient
Jul 2.2" 7.9" 0" ✅ Rainfall sufficient
Aug 2.2" 7" 0" ✅ Rainfall sufficient
Sep 2.2" 6.9" 0" ✅ Rainfall sufficient
Oct 2.2" 4.3" 0" ✅ Rainfall sufficient
Nov 2.2" 2.2" 0" ✅ Rainfall sufficient
Dec 2.2" 1.7" 0.5" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in Waller 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 ~1,275 GDD — county provides 6,141 GDD Excellent fit

Nasturtium Planting Timeline — Waller County, TX

Nasturtium Planting Calendar

Activity When Date Range
Start Indoors January 22 Jan 22 – Feb 5
Transplant Outdoors January 29 Jan 29 – Feb 12
Direct Sow January 29 Jan 29 – Feb 19
Bloom March 26 Mar 26 – Sep 24

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 9a

📆 Growing Season

288 days in Waller County

Growing Tips for Nasturtium in Waller County

Direct sow Nasturtium outdoors after February 19 in Waller County when soil has warmed and frost danger has passed.

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

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 Waller County, TX?

Waller County is in Zone 9a with an average last frost of February 19. Plan your Nasturtium planting based on this frost date — see the calendar above for exact timing.

What planting zone is Waller County, TX?

Waller County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 19 and first fall frost is December 4.

🌱

Your Waller County Garden Planner — Free

A 22-page printable planner built for Waller 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 Waller County, TX. Local conditions may vary. Last updated: June 2026.

Sources & credits

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