When to Plant Nasturtium in Marshall County, OK
Top priorities for Marshall County, Oklahoma gardeners in August
August is a pivotal month for Marshall County, Oklahoma gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Collect nasturtium at their peak
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
Get ahead of September
- 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.
Marshall County, Oklahoma is in USDA Zone 8a. The average last spring frost is March 24 and the first fall frost is November 12, giving you a growing season of approximately 233 days.
At an elevation of 520 feet, Marshall County receives approximately 23.7 inches of rainfall annually with predominantly loam soil. Summer highs average 92°F, providing good warmth for Nasturtium during the growing season.
Marshall County Soil Profile
Soil Type
Loam
Soil pH
6.2-7.8
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 Marshall County
How your county's soil matches Nasturtium's growing requirements.
Soil pH
Your soil pH (6.2–7.8) is within Nasturtium's preferred range (6.0–8.0).
Soil Texture
The loam soil in Marshall 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 (3.5%). Annual compost additions will help Nasturtium.
How to Plant Nasturtium
Succession Planting Nasturtium
Sow every 6.3 weeks. Last sowing by Sep 08 to harvest before frost.
Nasturtium Water Budget
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 | — | 0.5" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | 2.2" | 1.6" | 0.6" | 💧 Light watering |
| Apr | 2.2" | 2.3" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 4" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 2.8" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2.4" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 1.3" | 0.9" | 💧 Light watering |
| Nov | 2.2" | 0.9" | 1.3" | 🚿 Regular watering |
| Dec | — | 0.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Marshall 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 — Marshall County, OK
Nasturtium Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 24 | Feb 24 – Mar 10 |
| Transplant Outdoors | March 17 | Mar 17 – Mar 31 |
| Direct Sow | March 17 | Mar 17 – Apr 7 |
| Bloom | May 12 | May 12 – Oct 13 |
Plant 0.5" deep · 10" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | 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 · Only during dry spells
📅 Days to Maturity
55–65 days
🧪 Soil pH
Needs 6–8 · Your soil: ideal
🗺️ USDA Zone
Zone 8a
📆 Growing Season
233 days in Marshall County
Growing Tips for Nasturtium in Marshall County
Direct sow Nasturtium outdoors after March 24 in Marshall County when soil has warmed and frost danger has passed.
Marshall County receives only 24" of rain annually. Nasturtium needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
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 Marshall County, OK?
Marshall County is in Zone 8a with an average last frost of March 24. Plan your Nasturtium planting based on this frost date — see the calendar above for exact timing.
What planting zone is Marshall County, OK?
Marshall County, Oklahoma is in USDA Hardiness Zone 8a. The average last spring frost is March 24 and first fall frost is November 12.
Your Marshall County Garden Planner — Free
A 22-page printable planner built for Marshall 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.