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When to Plant Rhubarb in Delaware County, OK

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.

Delaware County, Oklahoma is in USDA Zone 7a. The average last spring frost is April 9 and the first fall frost is October 25, giving you a growing season of approximately 199 days.

At an elevation of 440 feet, Delaware County receives approximately 30.3 inches of rainfall annually with predominantly loam soil. Summer highs average 94ยฐF, providing good warmth for Rhubarb during the growing season.

Delaware County, OK (Zone 7a) Moderate season
199 days
Last Spring Frost April 9
199 growing days
First Fall Frost October 25

Delaware County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Apr 24
Recommended (50%) ✓ Fits season
Transplant: Apr 30
Safe Start (90%) ✓ Fits season
Transplant: May 14

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 766 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Rhubarb needs ~11,224 GDD — county provides 4,079 GDD May not mature

Rhubarb Planting Timeline โ€” Delaware County, OK

Rhubarb Planting Calendar

Activity When Date Range
Transplant Outdoors April 30 Apr 30 โ€“ May 14

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Transplant Outdoors
May Transplant Outdoors
June โ€”
July โ€”
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

365โ€“730 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 7a

Growing Season

199 days

Growing Tips for Delaware County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Rhubarb in Delaware County, OK?

Delaware County is in Zone 7a with an average last frost of April 9. Plan your Rhubarb planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Delaware County, OK?

Delaware County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is April 9 and first fall frost is October 25.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Delaware County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.

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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 Delaware County, OK. Local conditions may vary. Last updated: April 2026.