When to Plant Rue in Yellowstone County, MT
May to-do list for Yellowstone County, Montana
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
-
Harden off and plant rue
Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.
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.
Yellowstone County, Montana is in USDA Zone 5a. The average last spring frost is May 9 and the first fall frost is October 3, giving you a growing season of approximately 147 days.
At an elevation of 7,432 feet, Yellowstone County receives approximately 21.1 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.
Yellowstone County Soil Profile
Soil Type
Loam
Soil pH
6.2-8
Drainage
Well Drained
Plant Planting Risk Windows
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 Yellowstone County
How your county's soil matches Rue's growing requirements.
Soil pH
Your soil pH (6.2–8.0) overlaps with Rue's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Yellowstone County is excellent for Rue — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Rue.
Organic Matter
Organic matter is moderate (2.4%). Annual compost additions will help Rue.
How to Plant Rue
Succession Planting Rue
Sow every 8 weeks. Last sowing by Jul 05 to harvest before frost.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Rue
Rue needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.
| Month | Rue Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 1.9" | 0" | ❄️ Dormant |
| Apr | — | 1.9" | 0" | ❄️ Dormant |
| May | 2.2" | 2.7" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 1.7" | 0.5" | 💧 Light watering |
| Jul | 2.2" | 1.7" | 0.5" | 💧 Light watering |
| Aug | 2.2" | 2.5" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 1.7" | 0.5" | 💧 Light watering |
| Oct | 2.2" | 1.8" | 0.4" | 💧 Light watering |
| Nov | — | 1.6" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Yellowstone County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Rue 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.
Rue Planting Timeline — Yellowstone County, MT
Rue Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 16 | May 16 – May 30 |
| Harvest | July 25 | Jul 25 – Sep 26 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Only during dry spells
📅 Days to Maturity
70–90 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 5a
📆 Growing Season
147 days in Yellowstone County
Growing Tips for Rue in Yellowstone County
Direct sow Rue outdoors after May 09 in Yellowstone County when soil has warmed and frost danger has passed.
Yellowstone County receives only 21" of rain annually. Rue needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
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
Check more plant combinations with our Companion Planting Checker →
Rue in Other Locations
Frequently Asked Questions
When should I plant Rue in Yellowstone County, MT?
Yellowstone County is in Zone 5a with an average last frost of May 9. Plan your Rue planting based on this frost date — see the calendar above for exact timing.
What planting zone is Yellowstone County, MT?
Yellowstone County, Montana is in USDA Hardiness Zone 5a. The average last spring frost is May 9 and first fall frost is October 3.
Your Yellowstone County Garden Planner — Free
A 24-page printable planner built for Yellowstone County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.