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When to Plant Rhubarb in Somerset County, PA

Somerset County, Pennsylvania Zone 5b April

April in Somerset County, Pennsylvania — your action list

Your Somerset County, Pennsylvania garden is entering a new phase. Here's what's on the schedule for April and why each task matters now.

Avg. last frost May 6
Avg. first frost October 12
Soil temp (4") 44°F
Watering Moderate
Pest pressure Low
Daylight 13.1 hrs
May prep starts now
  • Transplants going out: rhubarb

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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.

Somerset County, Pennsylvania is in USDA Zone 5b. The average last spring frost is May 6 and the first fall frost is October 12, giving you a growing season of approximately 159 days.

At an elevation of 60 feet, Somerset County receives approximately 41.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Rhubarb to ensure they mature before fall.

Somerset County, PA (Zone 5b) Moderate season
159 days
Last Spring Frost May 6
159 growing days
First Fall Frost October 12
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Somerset County Soil Profile

Soil Type

Silt Loam

Soil pH

5.1-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: May 18
Recommended (50%) ✓ Fits season
Transplant: May 27
Safe Start (90%) ✓ Fits season
Transplant: Jun 12

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 Somerset County

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

Soil pH

Your soil pH (5.1–6.2) is more acidic than Rhubarb prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.0%). 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
1.1″/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 3.1" 0" ❄️ Dormant
Feb 2.8" 0" ❄️ Dormant
Mar 3.8" 0" ❄️ Dormant
Apr 3.1" 0" ❄️ Dormant
May 4.3" 3.2" 1.1" 💧 Light watering
Jun 4.3" 4.1" 0.2" 💧 Light watering
Jul 4.3" 4.5" 0" ✅ Rainfall sufficient
Aug 4.3" 3.3" 1" 💧 Light watering
Sep 4.3" 3.7" 0.6" 💧 Light watering
Oct 4.3" 3.7" 0.6" 💧 Light watering
Nov 3" 0" ❄️ Dormant
Dec 2.7" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Somerset 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 ~7,118 GDD — county provides 2,067 GDD May not mature

Rhubarb Planting Timeline — Somerset County, PA

Rhubarb Planting Calendar

Activity When Date Range
Transplant Outdoors May 27 May 27 – Jun 10

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June Transplant Outdoors
July
August
September
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

365–730 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 5b

📆 Growing Season

159 days in Somerset County

Growing Tips for Rhubarb in Somerset County

Direct sow Rhubarb outdoors after May 06 in Somerset County when soil has warmed and frost danger has passed.

Your 159.0-day growing season in Somerset 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 Somerset County, PA?

Somerset County is in Zone 5b with an average last frost of May 6. Plan your Rhubarb planting based on this frost date — see the calendar above for exact timing.

What planting zone is Somerset County, PA?

Somerset County, Pennsylvania is in USDA Hardiness Zone 5b. The average last spring frost is May 6 and first fall frost is October 12.

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Your Somerset County Garden Planner — Free

A 24-page printable planner built for Somerset County (Zone 5b). 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 Somerset County, PA. Local conditions may vary. Last updated: April 2026.

Sources & credits

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