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When to Plant Rhubarb in Woodward County, OK

Woodward County, Oklahoma Zone 7a May

Your May gardening checklist

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

Avg. last frost April 15
Avg. first frost October 22
Soil temp (4") 63°F
Watering Moderate
Pest pressure Low
Daylight 13.9 hrs
  1. Transplant rhubarb outside

    Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.

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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.

Woodward County, Oklahoma is in USDA Zone 7a. The average last spring frost is April 15 and the first fall frost is October 22, giving you a growing season of approximately 190 days.

At an elevation of 624 feet, Woodward County receives approximately 24.4 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Rhubarb during the growing season.

Woodward County, OK (Zone 7a) Moderate season
190 days
Last Spring Frost April 15
190 growing days
First Fall Frost October 22

Woodward County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Apr 29
Recommended (50%) ✓ Fits season
Transplant: May 6
Safe Start (90%) ✓ Fits season
Transplant: May 21

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 Woodward County

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

Soil pH

Your soil pH (6.3–7.7) overlaps with Rhubarb's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) — Rhubarb will thrive.

How to Plant Rhubarb

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 935 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

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 0.5" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 4.3" 2.9" 1.4" 💧 Light watering
May 4.3" 3.5" 0.8" 💧 Light watering
Jun 4.3" 3.4" 0.9" 💧 Light watering
Jul 4.3" 3.5" 0.8" 💧 Light watering
Aug 4.3" 3.3" 1" 💧 Light watering
Sep 4.3" 2.1" 2.2" 🚿 Regular watering
Oct 4.3" 1.3" 3" 🚿 Regular watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Woodward 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 2,612 GDD May not mature

Rhubarb Planting Timeline — Woodward County, OK

Rhubarb Planting Calendar

Activity When Date Range
Transplant Outdoors May 6 May 6 – May 20

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

365–730 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

190 days in Woodward County

Growing Tips for Rhubarb in Woodward County

Direct sow Rhubarb outdoors after April 15 in Woodward County when soil has warmed and frost danger has passed.

Your 190.0-day growing season in Woodward County is tight for Rhubarb (365.0-730.0 days to maturity). Start indoors and choose early-maturing varieties.

Woodward County receives only 24" of rain annually. Rhubarb needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Woodward County, OK?

Woodward County is in Zone 7a with an average last frost of April 15. Plan your Rhubarb planting based on this frost date — see the calendar above for exact timing.

What planting zone is Woodward County, OK?

Woodward County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is April 15 and first fall frost is October 22.

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Your Woodward County Garden Planner — Free

A 24-page printable planner built for Woodward 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 Woodward County, OK. Local conditions may vary. Last updated: May 2026.

Sources & credits

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