Blog

When to Plant Rue in Snohomish County, WA

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.

Snohomish County, Washington is in USDA Zone 8a. The average last spring frost is March 25 and the first fall frost is November 2, giving you a growing season of approximately 222 days.

At an elevation of 230 feet, Snohomish County receives approximately 50.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Rue during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Rue root diseases.

Snohomish County, WA (Zone 8a) Long season
222 days
Last Spring Frost March 25
222 growing days
First Fall Frost November 2

Snohomish County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (83 days to spare)
Transplant: Mar 26 🍅 Harvest: Jun 4 – Aug 6
Recommended (50%) ✓ Fits season (82 days to spare)
Transplant: Apr 1 🍅 Harvest: Jun 10 – Aug 12
Safe Start (90%) ✓ Fits season (81 days to spare)
Transplant: Apr 25 🍅 Harvest: Jul 4 – Sep 5

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 Snohomish County

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

Soil pH

Your soil pH (5.7โ€“6.8) overlaps with Rue's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.4%) โ€” Rue will thrive.

How to Plant Rue

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

Succession Planting Rue

3
successive plantings in your 222-day season

Sow every 8 weeks. Last sowing by Aug 04 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 โ€” 7.7" 0" โ„๏ธ Dormant
Feb โ€” 5.6" 0" โ„๏ธ Dormant
Mar 2.2" 5" 0" โœ… Rainfall sufficient
Apr 2.2" 3.6" 0" โœ… Rainfall sufficient
May 2.2" 2.6" 0" โœ… Rainfall sufficient
Jun 2.2" 1.6" 0.6" ๐Ÿ’ง Light watering
Jul 2.2" 0.7" 1.5" ๐Ÿšฟ Regular watering
Aug 2.2" 1" 1.2" ๐Ÿšฟ Regular watering
Sep 2.2" 2" 0.2" ๐Ÿ’ง Light watering
Oct 2.2" 4.2" 0" โœ… Rainfall sufficient
Nov 2.2" 8" 0" โœ… Rainfall sufficient
Dec โ€” 8.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Snohomish County). Supplement amounts are based on average rainfall โ€” 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" 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.

Rue needs ~1,400 GDD — county provides 3,885 GDD Excellent fit

Rue Planting Timeline โ€” Snohomish County, WA

Rue Planting Calendar

Activity When Date Range
Transplant Outdoors April 1 Apr 1 โ€“ Apr 15
Harvest June 10 Jun 10 โ€“ Aug 12

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

70โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

222 days in Snohomish County

Growing Tips for Rue in Snohomish County

Direct sow Rue outdoors after March 25 in Snohomish County when soil has warmed and frost danger has passed.

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 Snohomish County, WA?

Snohomish County is in Zone 8a with an average last frost of March 25. Plan your Rue planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Snohomish County, WA?

Snohomish County, Washington is in USDA Hardiness Zone 8a. The average last spring frost is March 25 and first fall frost is November 2.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Snohomish County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Snohomish County, WA. Local conditions may vary. Last updated: April 2026.