Blog

When to plant Rhubarb in Washington County, IL

In Washington County, Rhubarb is a spring-only crop. Plant April 30–May 14 once soil hits 50°F.

When to Plant Rhubarb in Washington County, IL

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.

Washington County, Illinois is in USDA Zone 6b. The average last spring frost is April 9 and the first fall frost is October 20, giving you a growing season of approximately 194 days.

At an elevation of 1,126 feet, Washington County receives approximately 33.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Rhubarb during the growing season.

Washington County, IL (Zone 6b) Moderate season
194 days
Last Spring Frost April 9
194 growing days
First Fall Frost October 20

Washington County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Rhubarb Planting Timeline — Washington County, IL

Rhubarb Planting Calendar

Activity When Date Range
Transplant Outdoors April 30 Apr 30 – May 14

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

365–730 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6b

📆 Growing Season

194 days in Washington County

Growing Tips for Washington 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Rhubarb in Washington County, IL?

Washington County is in Zone 6b with an average last frost of April 9. Plan your Rhubarb planting based on this frost date — see the calendar above for exact timing.

What planting zone is Washington County, IL?

Washington County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 9 and first fall frost is October 20.

When should I plant Rhubarb in Washington County, IL?

In Washington County, IL, plant Rhubarb after the last frost (around April 9) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Washington County, IL for Rhubarb?

Washington County sits in USDA Zone 6b. Rhubarb grows reliably in zones 3a through 8b, so it's a good fit here.

Can Rhubarb grow in Washington County's climate?

Yes — Rhubarb grows well in Washington County's temperate climate. Washington County averages a 194-day frost-free season, with last frost around April 9 and first frost around October 20.

🌱

Your Washington County Garden Planner — Free

A 22-page printable planner built for Washington County (Zone 6b). 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 Washington County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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