When to Plant Basil in Onslow County, NC
Top priorities for Onslow County, North Carolina gardeners in May
May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Onslow County, North Carolina.
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Start basil under lights
Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.
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It's harvest week for basil
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Before June arrives, get these ready
- 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.
Onslow County, North Carolina is in USDA Zone 8b. The average last spring frost is March 21 and the first fall frost is November 18, giving you a growing season of approximately 242 days.
At an elevation of 541 feet, Onslow County receives approximately 46.8 inches of rainfall annually with predominantly clay loam soil. Summer highs average 90°F, providing good warmth for Basil during the growing season. Clay soil retains moisture well for Basil, but amend with compost to improve drainage and prevent root rot.
Onslow County Soil Profile
Soil Type
Clay Loam
Soil pH
5.5-6.2
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 Onslow County
How your county's soil matches Basil's growing requirements.
Soil pH
Your soil pH (5.5–6.2) is more acidic than Basil prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The clay loam soil in Onslow County is excellent for Basil — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.3%). Annual compost additions will help Basil.
How to Plant Basil
Succession Planting Basil
Sow every 5.7 weeks. Last sowing by Sep 04 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 | — | 4" | 0" | ❄️ Dormant |
| Feb | — | 3.9" | 0" | ❄️ Dormant |
| Mar | 2.6" | 4.2" | 0" | ✅ Rainfall sufficient |
| Apr | 2.6" | 3.1" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 4" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 4.2" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 4.1" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 3.8" | 0" | ✅ Rainfall sufficient |
| Oct | 2.6" | 3.1" | 0" | ✅ Rainfall sufficient |
| Nov | 2.6" | 4" | 0" | ✅ Rainfall sufficient |
| Dec | — | 4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Onslow 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 — Onslow County, NC
Basil Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 31 | Jan 31 – Feb 14 |
| Transplant Outdoors | April 4 | Apr 4 – Apr 18 |
| Direct Sow | March 28 | Mar 28 – Apr 18 |
| Harvest | May 30 | May 30 – Aug 1 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors |
| March | Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.6"/week · Natural rainfall sufficient
📅 Days to Maturity
50–75 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 8b
📆 Growing Season
242 days in Onslow County
Growing Tips for Basil in Onslow County
Direct sow Basil outdoors after March 21 in Onslow County when soil has warmed and frost danger has passed.
With Onslow County's clay soil (30% clay), work in 3-4 inches of compost before planting Basil. Avoid tilling when soil is wet to prevent compaction.
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 Onslow County, NC?
Onslow County is in Zone 8b with an average last frost of March 21. Plan your Basil planting based on this frost date — see the calendar above for exact timing.
What planting zone is Onslow County, NC?
Onslow County, North Carolina is in USDA Hardiness Zone 8b. The average last spring frost is March 21 and first fall frost is November 18.
Your Onslow County Garden Planner — Free
A 24-page printable planner built for Onslow County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.