When to Plant Marigolds in Carter County, OK
Your May planting checklist for Carter County, Oklahoma
May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Carter County, Oklahoma.
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It's harvest week for marigolds
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
June will be here before you know it — start on
- First harvests: marigolds
Marigolds (Tagetes patula) are warm-season annuals beloved for their cheerful orange, yellow, and red blooms — and for their well-documented ability to repel pest nematodes in vegetable beds. Easy from seed, drought-tolerant once established, and bloom from early summer until the first hard frost.
Carter County, Oklahoma is in USDA Zone 8a. The average last spring frost is March 28 and the first fall frost is November 2, giving you a growing season of approximately 219 days.
At an elevation of 648 feet, Carter County receives approximately 34.2 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Marigolds during the growing season.
Carter County Soil Profile
Soil Type
Loam
Soil pH
6.4-7.5
Drainage
Well Drained
Plant 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 Carter County
How your county's soil matches Marigolds's growing requirements.
Soil pH
Your soil pH (6.4–7.5) is within Marigolds's preferred range (6.0–7.5).
Soil Texture
The loam soil in Carter County is excellent for Marigolds — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Marigolds.
Organic Matter
Organic matter is moderate (3.3%). Annual compost additions will help Marigolds.
How to Plant Marigolds
Succession Planting Marigolds
Sow every 5.7 weeks. Last sowing by Aug 24 to harvest before frost.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Marigolds
Marigolds 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 | Marigolds Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 0.8" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | 2.2" | 1.9" | 0.3" | 💧 Light watering |
| Apr | 2.2" | 3.1" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 5.8" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 6" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2.8" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.3" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 1.2" | 1" | 💧 Light watering |
| Dec | — | 0.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Carter County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Marigolds 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.
Marigolds Planting Timeline — Carter County, OK
Marigolds Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | May 9 | May 9 – May 23 |
| Transplant Outdoors | March 21 | Mar 21 – Apr 4 |
| Direct Sow | March 21 | Mar 21 – Apr 11 |
| Harvest | May 16 | May 16 – Sep 19 |
Plant 0.3" deep · 10" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Transplant Outdoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Start Indoors Harvest |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 6–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 8a
📆 Growing Season
219 days in Carter County
Growing Tips for Marigolds in Carter County
Direct sow Marigolds outdoors after March 28 in Carter County when soil has warmed and frost danger has passed.
Common pests for Marigolds in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct-sow after last frost or start indoors 4-6 weeks earlier. Deadhead spent blooms to keep new flowers coming. French marigolds (T. patula) are the most reliable nematode repellents — plant a band around vegetable beds. Tolerate poor soil but bloom best with monthly compost.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Very easy to save. Seeds are the long, thin, dark pieces inside the dried flower head.
Marigolds in Other Locations
Frequently Asked Questions
When should I plant Marigolds in Carter County, OK?
Carter County is in Zone 8a with an average last frost of March 28. Plan your Marigolds planting based on this frost date — see the calendar above for exact timing.
What planting zone is Carter County, OK?
Carter County, Oklahoma is in USDA Hardiness Zone 8a. The average last spring frost is March 28 and first fall frost is November 2.
Your Carter County Garden Planner — Free
A 24-page printable planner built for Carter 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.