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When to Plant Rhubarb in Meagher County, MT

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.

Meagher County, Montana is in USDA Zone 4a. The average last spring frost is June 10 and the first fall frost is September 8, giving you a growing season of approximately 90 days.

At an elevation of 5,072 feet, Meagher County receives approximately 14.2 inches of rainfall annually with predominantly loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Rhubarb to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Rhubarb successfully. Mulch heavily to conserve soil moisture.

Meagher County, MT (Zone 4a) Very short season
90 days
Last Spring Frost June 10
90 growing days
First Fall Frost September 8

Meagher County Soil Profile

Soil Type

Loam

Soil pH

6.5-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Jun 25
Recommended (50%) ✓ Fits season
Transplant: Jul 8
Safe Start (90%) ✓ Fits season
Transplant: Jul 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 Meagher County

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

Soil pH

Your soil pH (6.5โ€“8.0) is more alkaline than Rhubarb prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). 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
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 324 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” 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 โ€” 1" 0" โ„๏ธ Dormant
Feb โ€” 0.8" 0" โ„๏ธ Dormant
Mar โ€” 1.4" 0" โ„๏ธ Dormant
Apr โ€” 1.4" 0" โ„๏ธ Dormant
May โ€” 1.9" 0" โ„๏ธ Dormant
Jun 4.3" 0.9" 3.4" ๐Ÿšฟ Regular watering
Jul 4.3" 1.1" 3.2" ๐Ÿšฟ Regular watering
Aug 4.3" 1.5" 2.8" ๐Ÿšฟ Regular watering
Sep 4.3" 1.1" 3.2" ๐Ÿšฟ Regular watering
Oct โ€” 1.3" 0" โ„๏ธ Dormant
Nov โ€” 1" 0" โ„๏ธ Dormant
Dec โ€” 0.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Junโ€“Sep in Meagher 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 1,102 GDD May not mature

Rhubarb Planting Timeline โ€” Meagher County, MT

Rhubarb Planting Calendar

Activity When Date Range
Transplant Outdoors July 8 Jul 8 โ€“ Jul 22

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 โ€”
July Transplant Outdoors
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 1-2 times/week

๐Ÿ“… Days to Maturity

365โ€“730 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

90 days in Meagher County

Growing Tips for Rhubarb in Meagher County

Direct sow Rhubarb outdoors after June 10 in Meagher County when soil has warmed and frost danger has passed.

Your 90.0-day growing season in Meagher County is tight for Rhubarb (365.0-730.0 days to maturity). Start indoors and choose early-maturing varieties.

Meagher County receives only 14" of rain annually. Rhubarb needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

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 Meagher County, MT?

Meagher County is in Zone 4a with an average last frost of June 10. Plan your Rhubarb planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Meagher County, MT?

Meagher County, Montana is in USDA Hardiness Zone 4a. The average last spring frost is June 10 and first fall frost is September 8.

๐ŸŒฑ

Plan Your Garden with Confidence

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

Get Your Free Garden Planner →

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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 Meagher County, MT. Local conditions may vary. Last updated: April 2026.