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When to Plant Rhubarb in Windsor County, VT

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.

Windsor County, Vermont is in USDA Zone 4b. The average last spring frost is May 12 and the first fall frost is October 7, giving you a growing season of approximately 148 days.

At an elevation of 309 feet, Windsor County receives approximately 48.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Rhubarb to ensure they mature before fall.

Windsor County, VT (Zone 4b) Short season
148 days
Last Spring Frost May 12
148 growing days
First Fall Frost October 7

Windsor County Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Jun 3
Recommended (50%) ✓ Fits season
Transplant: Jun 9
Safe Start (90%) ✓ Fits season
Transplant: Jun 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 Windsor County

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

Soil pH

Your soil pH (4.9โ€“6.5) is more acidic than Rhubarb prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Windsor County is excellent for Rhubarb โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.6%). 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
1.4″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 โ€” 3.2" 0" โ„๏ธ Dormant
Feb โ€” 3.4" 0" โ„๏ธ Dormant
Mar โ€” 3.9" 0" โ„๏ธ Dormant
Apr โ€” 3.9" 0" โ„๏ธ Dormant
May 4.3" 4" 0.3" ๐Ÿ’ง Light watering
Jun 4.3" 4.5" 0" โœ… Rainfall sufficient
Jul 4.3" 4.7" 0" โœ… Rainfall sufficient
Aug 4.3" 4.6" 0" โœ… Rainfall sufficient
Sep 4.3" 4.6" 0" โœ… Rainfall sufficient
Oct 4.3" 4.5" 0" โœ… Rainfall sufficient
Nov โ€” 3.5" 0" โ„๏ธ Dormant
Dec โ€” 4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Windsor County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~6,707 GDD — county provides 1,813 GDD May not mature

Rhubarb Planting Timeline โ€” Windsor County, VT

Rhubarb Planting Calendar

Activity When Date Range
Transplant Outdoors June 9 Jun 9 โ€“ Jun 23

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

365โ€“730 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

148 days in Windsor County

Growing Tips for Rhubarb in Windsor County

Direct sow Rhubarb outdoors after May 12 in Windsor County when soil has warmed and frost danger has passed.

Your 148.0-day growing season in Windsor 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 Windsor County, VT?

Windsor County is in Zone 4b with an average last frost of May 12. Plan your Rhubarb planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Windsor County, VT?

Windsor County, Vermont is in USDA Hardiness Zone 4b. The average last spring frost is May 12 and first fall frost is October 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Windsor County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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