Blog

When to Plant Rue in Canyon County, ID

Canyon County, Idaho Zone 7a May

Canyon County, Idaho gardeners: here's your May plan

We've pulled the most time-sensitive tasks for Canyon County, Idaho this May and put them front and centre. Tackle them in order.

Avg. last frost May 4
Avg. first frost October 10
Soil temp (4") 47°F
Watering High
Pest pressure Low
Daylight 14.5 hrs
  1. Move rue from tray to bed

    Your last frost (May 4) has passed. These warm-season crops can handle outdoor soil now.

Instant PDF download. No spam, unsubscribe any time.

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.

Canyon County, Idaho is in USDA Zone 7a. The average last spring frost is May 4 and the first fall frost is October 10, giving you a growing season of approximately 159 days.

At an elevation of 4,953 feet, Canyon County receives approximately 13.3 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Rue during the growing season. With low rainfall, drip irrigation is essential for growing Rue successfully. Mulch heavily to conserve soil moisture.

Canyon County, ID (Zone 7a) Moderate season
159 days
Last Spring Frost May 4
159 growing days
First Fall Frost October 10

Canyon County Soil Profile

Soil Type

Loam

Soil pH

6.2-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (26 days to spare)
Transplant: Apr 27 🍅 Harvest: Jul 6 – Sep 7
Recommended (50%) ✓ Fits season (19 days to spare)
Transplant: May 11 🍅 Harvest: Jul 20 – Sep 21
Safe Start (90%) ✓ Fits season (2 days to spare)
Transplant: Jun 13 🍅 Harvest: Aug 22 – Oct 24

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 Canyon County

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

Soil pH

Your soil pH (6.2–8.2) overlaps with Rue's range (6.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Canyon County is excellent for Rue — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Rue.

How to Plant Rue

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Rue

2
successive plantings in your 159-day season

Sow every 8 weeks. Last sowing by Jul 12 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.4″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 252 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 0.8" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 1.6" 0" ❄️ Dormant
May 2.2" 1.4" 0.8" 💧 Light watering
Jun 2.2" 1.1" 1.1" 🚿 Regular watering
Jul 2.2" 1" 1.2" 🚿 Regular watering
Aug 2.2" 1.6" 0.6" 💧 Light watering
Sep 2.2" 1" 1.2" 🚿 Regular watering
Oct 2.2" 1.1" 1.1" 🚿 Regular watering
Nov 1" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Canyon 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 needs ~1,220 GDD — county provides 2,424 GDD Excellent fit

Rue Planting Timeline — Canyon County, ID

Rue Planting Calendar

Activity When Date Range
Transplant Outdoors May 11 May 11 – May 25
Harvest July 20 Jul 20 – Sep 21

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

Month-by-Month Timeline

MonthActivities
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 7a

📆 Growing Season

159 days in Canyon County

Growing Tips for Rue in Canyon County

Direct sow Rue outdoors after May 04 in Canyon County when soil has warmed and frost danger has passed.

Canyon County receives only 13" 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

  • Basil
  • Sage

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Rue in Canyon County, ID?

Canyon County is in Zone 7a with an average last frost of May 4. Plan your Rue planting based on this frost date — see the calendar above for exact timing.

What planting zone is Canyon County, ID?

Canyon County, Idaho is in USDA Hardiness Zone 7a. The average last spring frost is May 4 and first fall frost is October 10.

🌱

Your Canyon County Garden Planner — Free

A 24-page printable planner built for Canyon County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Canyon County, ID. 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.