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When to Plant Nasturtium in Grimes County, TX

Grimes County, Texas Zone 9a June

Top priorities for Grimes County, Texas gardeners in June

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

Avg. last frost February 25
Avg. first frost December 1
Soil temp (4") 82°F
Watering Low
Pest pressure High
Daylight 14 hrs
  1. It's harvest week for nasturtium

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

A few tasks this June that'll pay off in July
  • 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.

Grimes County, Texas is in USDA Zone 9a. The average last spring frost is February 25 and the first fall frost is December 1, giving you a growing season of approximately 279 days.

At an elevation of 33 feet, Grimes County receives approximately 65.2 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 91°F, providing good warmth for Nasturtium during the growing season. 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
Grimes County, TX (Zone 9a) Year-round
279 days
Last Spring Frost February 25
279 growing days
First Fall Frost December 1
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Grimes County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.8-6.5

Drainage

Well Drained

Nasturtium Planting Risk Windows

Early Start (70% safe) ✓ Fits season (66 days to spare)
Start indoors: Jan 15 Transplant: Jan 22 🌸 Bloom: Mar 19 – Sep 17
Recommended (50%) ✓ Fits season (62 days to spare)
Start indoors: Jan 28 Transplant: Feb 4 🌸 Bloom: Apr 1 – Sep 30
Safe Start (90%) ✓ Fits season (65 days to spare)
Start indoors: Feb 11 Transplant: Feb 18 🌸 Bloom: Apr 15 – Oct 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 Grimes County

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

Soil pH

Your soil pH (5.8–6.5) overlaps with Nasturtium's range (6.0–8.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Nasturtium.

Organic Matter

Organic matter is low (1.7%). 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

6
successive plantings in your 279-day season

Sow every 6.3 weeks. Last sowing by Sep 27 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 6/10 — 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 1.9" 0" ❄️ Dormant
Feb 2.2" 2.1" 0.1" 💧 Light watering
Mar 2.2" 4.7" 0" ✅ Rainfall sufficient
Apr 2.2" 6" 0" ✅ Rainfall sufficient
May 2.2" 9.9" 0" ✅ Rainfall sufficient
Jun 2.2" 9.9" 0" ✅ Rainfall sufficient
Jul 2.2" 8.3" 0" ✅ Rainfall sufficient
Aug 2.2" 8.3" 0" ✅ Rainfall sufficient
Sep 2.2" 6.6" 0" ✅ Rainfall sufficient
Oct 2.2" 3.9" 0" ✅ Rainfall sufficient
Nov 2.2" 2" 0.2" 💧 Light watering
Dec 2.2" 1.7" 0.5" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in Grimes 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 ~1,095 GDD — county provides 5,110 GDD Excellent fit

Nasturtium Planting Timeline — Grimes County, TX

Nasturtium Planting Calendar

Activity When Date Range
Start Indoors January 28 Jan 28 – Feb 11
Transplant Outdoors February 4 Feb 4 – Feb 18
Direct Sow February 4 Feb 4 – Feb 25
Bloom April 1 Apr 1 – Sep 30

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
November
December
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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: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

279 days in Grimes County

Growing Tips for Nasturtium in Grimes County

Direct sow Nasturtium outdoors after February 25 in Grimes County when soil has warmed and frost danger has passed.

Sandy soil in Grimes 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 Grimes County, TX?

Grimes County is in Zone 9a with an average last frost of February 25. Plan your Nasturtium planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grimes County, TX?

Grimes County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 25 and first fall frost is December 1.

🌱

Your Grimes County Garden Planner — Free

A 22-page printable planner built for Grimes 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 Grimes 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.