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When to Plant Rhubarb in Garvin County, OK

Garvin County, Oklahoma Zone 7b May

Your May gardening checklist

Each item below is timed to Garvin County, Oklahoma's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 4
Avg. first frost November 3
Soil temp (4") 66°F
Watering Low
Pest pressure Moderate
Daylight 13.8 hrs

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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.

Garvin County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 4 and the first fall frost is November 3, giving you a growing season of approximately 213 days.

At an elevation of 515 feet, Garvin County receives approximately 31.4 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Rhubarb during the growing season.

Garvin County, OK (Zone 7b) Long season
213 days
Last Spring Frost April 4
213 growing days
First Fall Frost November 3
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Garvin County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Apr 16
Recommended (50%) ✓ Fits season
Transplant: Apr 25
Safe Start (90%) ✓ Fits season
Transplant: May 6

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 Garvin County

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

Soil pH

Your soil pH (6.3–7.2) overlaps with Rhubarb's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.3%). 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
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 866 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 0.7" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.1" 0.2" 💧 Light watering
Aug 4.3" 4.1" 0.2" 💧 Light watering
Sep 4.3" 2.9" 1.4" 💧 Light watering
Oct 4.3" 2.1" 2.2" 🚿 Regular watering
Nov 4.3" 1.1" 3.2" 🚿 Regular watering
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Garvin 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 ~10,813 GDD — county provides 4,206 GDD May not mature

Rhubarb Planting Timeline — Garvin County, OK

Rhubarb Planting Calendar

Activity When Date Range
Transplant Outdoors April 25 Apr 25 – May 9

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Transplant Outdoors
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 · 1-2 times/week

📅 Days to Maturity

365–730 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

213 days in Garvin County

Growing Tips for Rhubarb in Garvin County

Direct sow Rhubarb outdoors after April 04 in Garvin County when soil has warmed and frost danger has passed.

Your 213.0-day growing season in Garvin 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 Garvin County, OK?

Garvin County is in Zone 7b with an average last frost of April 4. Plan your Rhubarb planting based on this frost date — see the calendar above for exact timing.

What planting zone is Garvin County, OK?

Garvin County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 4 and first fall frost is November 3.

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Your Garvin County Garden Planner — Free

A 24-page printable planner built for Garvin 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.

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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 Garvin County, OK. 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.