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When to plant Rue in Custer County, MT

In Custer County, Rue is a single-season spring crop — there's no second fall window. Plant May 21–June 4 for an 70–90-day harvest, finishing well before the September 27 first frost.

When to Plant Rue in Custer County, MT

Rue is a bitter, aromatic perennial herb with bluish-green foliage used historically in medicine and as a pest deterrent. Handle with care as its sap can cause skin irritation.

Custer County, Montana is in USDA Zone 4b. The average last spring frost is May 14 and the first fall frost is September 27, giving you a growing season of approximately 136 days.

At an elevation of 5,983 feet, Custer County receives approximately 24 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Rue to ensure they mature before fall.

Custer County, MT (Zone 4b) Short season
136 days
Last Spring Frost May 14
136 growing days
First Fall Frost September 27

Custer County Soil Profile

Soil Type

Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Rue Planting Timeline — Custer County, MT

Rue Planting Calendar

Activity When Date Range
Transplant Outdoors May 21 May 21 – Jun 4
Harvest July 30 Jul 30 – Oct 1

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 4b

📆 Growing Season

136 days in Custer County

Growing Tips for Custer County

Start seeds indoors or direct sow. Plant in well-drained soil. Wear gloves when handling as sap can cause phytophotodermatitis. Prune in early spring.

Companion Planting

Good Companions

Avoid Planting Near

  • Basil
  • Sage

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Rue in Custer County, MT?

Custer County is in Zone 4b with an average last frost of May 14. Plan your Rue planting based on this frost date — see the calendar above for exact timing.

What planting zone is Custer County, MT?

Custer County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is May 14 and first fall frost is September 27.

When should I plant Rue in Custer County, MT?

In Custer County, MT, plant Rue after the last frost (around May 14) and before the first frost (around September 27). Best results when soil holds above 50°F.

What growing zone is Custer County, MT for Rue?

Custer County sits in USDA Zone 4b. Rue grows reliably in zones 4a through 9b, so it's a good fit here.

Can Rue grow in Custer County's climate?

Yes — Rue grows well in Custer County's temperate climate. Custer County averages a 136-day frost-free season, with last frost around May 14 and first frost around September 27.

🌱

Your Custer County Garden Planner — Free

A 22-page printable planner built for Custer County (Zone 4b). 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 Custer County, MT. Local conditions may vary. Last updated: June 2026.

Sources & credits

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