When to Plant Basil in Jefferson County, OK
Your May gardening checklist
Your garden in Jefferson County, Oklahoma is working on a schedule, even when you're not. Here's where you should be this May.
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Indoor seed-starting week for basil
Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.
To set up a strong June, finish these tasks
- First harvests: basil
Basil is a fragrant warm-season herb essential to Italian and Thai cuisines. It comes in many varieties including sweet, Thai, purple, and lemon types.
Jefferson County, Oklahoma is in USDA Zone 8a. The average last spring frost is March 26 and the first fall frost is November 9, giving you a growing season of approximately 228 days.
At an elevation of 883 feet, Jefferson County receives approximately 24.7 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Basil during the growing season.
Jefferson County Soil Profile
Soil Type
Loam
Soil pH
6.6-7.5
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 Jefferson County
How your county's soil matches Basil's growing requirements.
Soil pH
Your soil pH (6.6–7.5) is more alkaline than Basil prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Jefferson County is excellent for Basil — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.1%) — Basil will thrive.
How to Plant Basil
Succession Planting Basil
Sow every 5.7 weeks. Last sowing by Aug 26 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Basil
Basil needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.
| Month | Basil Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 0.6" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | 2.6" | 1.7" | 0.9" | 💧 Light watering |
| Apr | 2.6" | 2.7" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 3.2" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 4" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 3.1" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 3.2" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 2.1" | 0.5" | 💧 Light watering |
| Oct | 2.6" | 1.6" | 1" | 💧 Light watering |
| Nov | 2.6" | 0.8" | 1.8" | 🚿 Regular watering |
| Dec | — | 0.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Jefferson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Basil 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.
Basil Planting Timeline — Jefferson County, OK
Basil Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 5 | Feb 5 – Feb 19 |
| Transplant Outdoors | April 9 | Apr 9 – Apr 23 |
| Direct Sow | April 2 | Apr 2 – Apr 23 |
| Harvest | June 4 | Jun 4 – Aug 6 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | — |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.6"/week · Only during dry spells
📅 Days to Maturity
50–75 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 8a
📆 Growing Season
228 days in Jefferson County
Growing Tips for Basil in Jefferson County
Direct sow Basil outdoors after March 26 in Jefferson County when soil has warmed and frost danger has passed.
General growing tips
Start seeds indoors or direct sow after last frost. Pinch flower buds to extend leaf production. Harvest leaves from the top down, cutting just above a leaf pair.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Isolate 150 ft between varieties. Different basil species can cross.
Basil in Other Locations
Frequently Asked Questions
When should I plant Basil in Jefferson County, OK?
Jefferson County is in Zone 8a with an average last frost of March 26. Plan your Basil planting based on this frost date — see the calendar above for exact timing.
What planting zone is Jefferson County, OK?
Jefferson County, Oklahoma is in USDA Hardiness Zone 8a. The average last spring frost is March 26 and first fall frost is November 9.
Your Jefferson County Garden Planner — Free
A 24-page printable planner built for Jefferson 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.