When to Plant Amaranth in Onslow County, NC
Amaranth is an ancient grain crop with edible leaves and seeds, rich in protein and micronutrients. It thrives in warm conditions and is drought-tolerant once established.
Onslow County, North Carolina is in USDA Zone 8a. 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 Amaranth during the growing season. Clay soil retains moisture well for Amaranth, 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 Amaranth's growing requirements.
Soil pH
Your soil pH (5.5–6.2) is more acidic than Amaranth prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The clay loam soil in Onslow County is excellent for Amaranth — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.3%). Annual compost additions will help Amaranth.
How to Plant Amaranth
Plant Water Budget
Monthly Watering Guide for Amaranth
Amaranth needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Amaranth Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 4" | 0" | ❄️ Dormant |
| Feb | — | 3.9" | 0" | ❄️ Dormant |
| Mar | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Apr | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| May | 4.3" | 4" | 0.3" | 💧 Light watering |
| Jun | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Jul | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Sep | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Oct | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Nov | 4.3" | 4" | 0.3" | 💧 Light watering |
| 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.
Amaranth 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.
Amaranth Planting Timeline — Onslow County, NC
Amaranth 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 | July 4 | Jul 4 – Aug 22 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors |
| March | Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | — |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 8a
📆 Growing Season
242 days in Onslow County
Growing Tips for Amaranth in Onslow County
Direct sow Amaranth 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 Amaranth. Avoid tilling when soil is wet to prevent compaction.
General growing tips
Direct sow after last frost when soil is warm. Thin seedlings to 18 inches apart. Harvest leaves when young and tender; harvest seeds when flower heads begin to dry.
Companion Planting
Good Companions
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Amaranth in Other Locations
Frequently Asked Questions
When should I plant Amaranth in Onslow County, NC?
Onslow County is in Zone 8a with an average last frost of March 21. Plan your Amaranth 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 8a. The average last spring frost is March 21 and first fall frost is November 18.
Plan Your Garden with Confidence
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