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When to Plant Rhubarb in Madison County, NC

Madison County, North Carolina Zone 7a May

What to do in May

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Madison County, North Carolina.

Avg. last frost April 11
Avg. first frost October 24
Soil temp (4") 60°F
Watering Low
Pest pressure Low
Daylight 13.9 hrs
  1. Move rhubarb from tray to bed

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

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Rhubarb is a long-lived perennial vegetable grown for its tart, colorful stalks. Only the stalks are edible as the leaves contain toxic oxalic acid.

Madison County, North Carolina is in USDA Zone 7a. The average last spring frost is April 11 and the first fall frost is October 24, giving you a growing season of approximately 196 days.

At an elevation of 2,664 feet, Madison County receives approximately 43.1 inches of rainfall annually with predominantly clay loam soil. Summer highs average 85°F, providing good warmth for Rhubarb during the growing season. Clay soil retains moisture well for Rhubarb, but amend with compost to improve drainage and prevent root rot.

Madison County, NC (Zone 7a) Moderate season
196 days
Last Spring Frost April 11
196 growing days
First Fall Frost October 24
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Madison 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
Transplant: Apr 28
Recommended (50%) ✓ Fits season
Transplant: May 2
Safe Start (90%) ✓ Fits season
Transplant: May 22

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 Madison County

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

Soil pH

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

Soil Texture

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

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Rhubarb.

How to Plant Rhubarb

1"
Planting Depth
30"
Between Plants
42"
Between Rows

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 133 gal / 100 sq ft

Monthly Watering Guide for Rhubarb

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

Month Rhubarb Needs Rainfall You Supplement Action
Jan 3.9" 0" ❄️ Dormant
Feb 3.5" 0" ❄️ Dormant
Mar 4.4" 0" ❄️ Dormant
Apr 4.3" 3" 1.3" 💧 Light watering
May 4.3" 3.9" 0.4" 💧 Light watering
Jun 4.3" 3.4" 0.9" 💧 Light watering
Jul 4.3" 4.2" 0.1" 💧 Light watering
Aug 4.3" 3.8" 0.5" 💧 Light watering
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 3.6" 0" ❄️ Dormant
Dec 3.6" 0" ❄️ Dormant

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

Rhubarb 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.

Rhubarb needs ~7,528 GDD — county provides 2,695 GDD May not mature

Rhubarb Planting Timeline — Madison County, NC

Rhubarb Planting Calendar

Activity When Date Range
Transplant Outdoors May 2 May 2 – May 16

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June
July
August
September
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

365–730 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7a

📆 Growing Season

196 days in Madison County

Growing Tips for Rhubarb in Madison County

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

With Madison County's clay soil (31% clay), work in 3-4 inches of compost before planting Rhubarb. Avoid tilling when soil is wet to prevent compaction.

Your 196.0-day growing season in Madison County is tight for Rhubarb (365.0-730.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Plant crowns in early spring in rich, well-drained soil. Do not harvest stalks the first year. Pull (do not cut) stalks at harvest to avoid introducing rot.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Rhubarb in Madison County, NC?

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

What planting zone is Madison County, NC?

Madison County, North Carolina is in USDA Hardiness Zone 7a. The average last spring frost is April 11 and first fall frost is October 24.

🌱

Your Madison County Garden Planner — Free

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

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

Sources & credits

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