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When to Plant Rhubarb in Essex County, MA

Essex County, Massachusetts Zone 6b May

Your May game plan for Essex County, Massachusetts

Welcome to May in Zone 6b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 24
Avg. first frost October 17
Soil temp (4") 63°F
Watering Moderate
Pest pressure Low
Daylight 14.4 hrs
  1. Move rhubarb from tray to bed

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

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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.

Essex County, Massachusetts is in USDA Zone 6b. The average last spring frost is April 24 and the first fall frost is October 17, giving you a growing season of approximately 176 days.

At an elevation of 668 feet, Essex County receives approximately 41.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Rhubarb during the growing season.

Essex County, MA (Zone 6b) Moderate season
176 days
Last Spring Frost April 24
176 growing days
First Fall Frost October 17

Essex County Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: May 11
Recommended (50%) ✓ Fits season
Transplant: May 15
Safe Start (90%) ✓ Fits season
Transplant: Jun 3

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 Essex County

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

Soil pH

Your soil pH (4.9–6.3) is more acidic than Rhubarb prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.2%). 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
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 11 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 2.7" 0" ❄️ Dormant
Feb 2.9" 0" ❄️ Dormant
Mar 3.8" 0" ❄️ Dormant
Apr 4.3" 3.4" 0.9" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 4.2" 0.1" 💧 Light watering
Jul 4.3" 4.2" 0.1" 💧 Light watering
Aug 4.3" 3.7" 0.6" 💧 Light watering
Sep 4.3" 3.7" 0.6" 💧 Light watering
Oct 4.3" 3" 1.3" 💧 Light watering
Nov 3.6" 0" ❄️ Dormant
Dec 2.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Essex 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 ~8,760 GDD — county provides 2,816 GDD May not mature

Rhubarb Planting Timeline — Essex County, MA

Rhubarb Planting Calendar

Activity When Date Range
Transplant Outdoors May 15 May 15 – May 29

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 · Only during dry spells

📅 Days to Maturity

365–730 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

176 days in Essex County

Growing Tips for Rhubarb in Essex County

Direct sow Rhubarb outdoors after April 24 in Essex County when soil has warmed and frost danger has passed.

Your 176.0-day growing season in Essex 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 Essex County, MA?

Essex County is in Zone 6b with an average last frost of April 24. Plan your Rhubarb planting based on this frost date — see the calendar above for exact timing.

What planting zone is Essex County, MA?

Essex County, Massachusetts is in USDA Hardiness Zone 6b. The average last spring frost is April 24 and first fall frost is October 17.

🌱

Your Essex County Garden Planner — Free

A 24-page printable planner built for Essex 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.

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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 Essex County, MA. 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.