When to Plant Nasturtium in Karnes County, TX
Your July planting checklist for Karnes County, Texas
Your garden in Karnes County, Texas is working on a schedule, even when you're not. Here's where you should be this July.
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It's harvest week for nasturtium
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
August will be here before you know it — start on
- First harvests: nasturtium
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.
Karnes County, Texas is in USDA Zone 9a. The average last spring frost is February 26 and the first fall frost is November 30, giving you a growing season of approximately 277 days.
At an elevation of 4,532 feet, Karnes County receives approximately 67.2 inches of rainfall annually with predominantly loam soil. Summer highs average 95°F, so Nasturtium may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Nasturtium root diseases.
Karnes County Soil Profile
Soil Type
Loam
Soil pH
6.3-7.8
Drainage
Well Drained
Nasturtium Planting Risk Windows
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 Karnes County
How your county's soil matches Nasturtium's growing requirements.
Soil pH
Your soil pH (6.3–7.8) is within Nasturtium's preferred range (6.0–8.0).
Soil Texture
The loam soil in Karnes County is excellent for Nasturtium — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Nasturtium.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Nasturtium.
How to Plant Nasturtium
Succession Planting Nasturtium
Sow every 6.3 weeks. Last sowing by Sep 26 to harvest before frost.
Nasturtium Water Budget
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 | — | 1.6" | 0" | ❄️ Dormant |
| Feb | 2.2" | 2.6" | 0" | ✅ Rainfall sufficient |
| Mar | 2.2" | 4.6" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 6.3" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 8.6" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 11.7" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 9.1" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 8.7" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 6.7" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 2" | 0.2" | 💧 Light watering |
| Dec | — | 1.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Feb–Nov in Karnes 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 Planting Timeline — Karnes County, TX
Nasturtium Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 29 | Jan 29 – Feb 12 |
| Transplant Outdoors | February 5 | Feb 5 – Feb 19 |
| Direct Sow | February 5 | Feb 5 – Feb 26 |
| Bloom | April 2 | Apr 2 – Oct 1 |
Plant 0.5" deep · 10" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
55–65 days
🧪 Soil pH
Needs 6–8 · Your soil: ideal
🗺️ USDA Zone
Zone 9a
📆 Growing Season
277 days in Karnes County
Growing Tips for Nasturtium in Karnes County
Direct sow Nasturtium outdoors after February 26 in Karnes County when soil has warmed and frost danger has passed.
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
Check more plant combinations with our Companion Planting Checker →
Nasturtium in Other Locations
Frequently Asked Questions
When should I plant Nasturtium in Karnes County, TX?
Karnes County is in Zone 9a with an average last frost of February 26. Plan your Nasturtium planting based on this frost date — see the calendar above for exact timing.
What planting zone is Karnes County, TX?
Karnes County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 26 and first fall frost is November 30.
Your Karnes County Garden Planner — Free
A 22-page printable planner built for Karnes 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.