Blog

When to Plant Onion in Macon County, NC

Macon County, North Carolina Zone 7b May

May in Macon County, North Carolina — your action list

We've pulled the most time-sensitive tasks for Macon County, North Carolina this May and put them front and centre. Tackle them in order.

Avg. last frost April 11
Avg. first frost October 23
Soil temp (4") 63°F
Watering Moderate
Pest pressure Moderate
Daylight 13.8 hrs
  1. Start onion indoors

    Label every cell. You will absolutely forget which is which otherwise.

Instant PDF download. No spam, unsubscribe any time.

Onions are a fundamental kitchen staple available in yellow, white, and red varieties. Choose long-day, short-day, or intermediate types based on your latitude.

Macon County, North Carolina is in USDA Zone 7b. The average last spring frost is April 11 and the first fall frost is October 23, giving you a growing season of approximately 195 days.

At an elevation of 2,597 feet, Macon County receives approximately 40.1 inches of rainfall annually with predominantly clay loam soil. Summer highs average 88°F, providing good warmth for Onion during the growing season. Clay soil retains moisture well for Onion, but amend with compost to improve drainage and prevent root rot.

Macon County, NC (Zone 7b) Moderate season
195 days
Last Spring Frost April 11
195 growing days
First Fall Frost October 23

Macon County Soil Profile

Soil Type

Clay Loam

Soil pH

5.6-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (59 days to spare)
Start indoors: Feb 25 Transplant: Apr 1 🍅 Harvest: Jul 1 – Aug 19
Recommended (50%) ✓ Fits season (55 days to spare)
Start indoors: Mar 7 Transplant: Apr 11 🍅 Harvest: Jul 11 – Aug 29
Safe Start (90%) ✓ Fits season (63 days to spare)
Start indoors: Mar 29 Transplant: May 3 🍅 Harvest: Aug 2 – Sep 20

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 Macon County

How your county's soil matches Onion's growing requirements.

Soil pH

Your soil pH (5.6–6.3) is more acidic than Onion prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The clay loam soil in Macon County is excellent for Onion — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Onion.

How to Plant Onion

1"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 237 gal / 100 sq ft

Monthly Watering Guide for Onion

Onion needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Onion Needs Rainfall You Supplement Action
Jan 3.7" 0" ❄️ Dormant
Feb 3.3" 0" ❄️ Dormant
Mar 3.7" 0" ❄️ Dormant
Apr 4.3" 2.9" 1.4" 💧 Light watering
May 4.3" 3.3" 1" 💧 Light watering
Jun 4.3" 3.4" 0.9" 💧 Light watering
Jul 4.3" 4.4" 0" ✅ Rainfall sufficient
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 3" 1.3" 💧 Light watering
Oct 4.3" 2.4" 1.9" 💧 Light watering
Nov 2.8" 0" ❄️ Dormant
Dec 3.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Macon County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Onion 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.

Onion needs ~1,680 GDD — county provides 3,120 GDD Excellent fit

Onion Planting Timeline — Macon County, NC

Onion Planting Calendar

Activity When Date Range
Start Indoors March 7 Mar 7 – Mar 21
Transplant Outdoors April 11 Apr 11 – Apr 25
Direct Sow March 28 Mar 28 – Apr 18
Harvest July 11 Jul 11 – Aug 29
Fall Sowing August 14 Aug 14 – Aug 28

Plant 1" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May
June
July Harvest
August Fall Sowing 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 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7b

📆 Growing Season

195 days in Macon County

Growing Tips for Onion in Macon County

Direct sow Onion outdoors after April 11 in Macon County when soil has warmed and frost danger has passed.

With Macon County's clay soil (30% clay), work in 3-4 inches of compost before planting Onion. Avoid tilling when soil is wet to prevent compaction.

Common pests for Onion in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 8-10 weeks before transplanting. Match day-length type to your latitude. Stop watering when tops begin to fall over and cure bulbs for 2-3 weeks before storage.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans
  • Asparagus

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Onion in Macon County, NC?

Macon County is in Zone 7b with an average last frost of April 11. Plan your Onion planting based on this frost date — see the calendar above for exact timing.

What planting zone is Macon County, NC?

Macon County, North Carolina is in USDA Hardiness Zone 7b. The average last spring frost is April 11 and first fall frost is October 23.

🌱

Your Macon County Garden Planner — Free

A 24-page printable planner built for Macon County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Macon County, NC. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.