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When to Plant Dill in Snohomish County, WA

Dill is a feathery annual herb with aromatic leaves and seeds. Its fine foliage and umbrella-shaped flower heads attract beneficial insects to the garden.

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 Dill during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Dill 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 (125 days to spare)
Start indoors: Feb 12 Transplant: Mar 12 🍅 Harvest: Apr 23 – Jun 25
Recommended (50%) ✓ Fits season (124 days to spare)
Start indoors: Feb 18 Transplant: Mar 18 🍅 Harvest: Apr 29 – Jul 1
Safe Start (90%) ✓ Fits season (123 days to spare)
Start indoors: Mar 14 Transplant: Apr 11 🍅 Harvest: May 23 – Jul 25

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 Dill's growing requirements.

Soil pH

Your soil pH (5.7โ€“6.8) is within Dill's preferred range (5.5โ€“7.0).

Soil Texture

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

Organic Matter

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

How to Plant Dill

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Dill

6
successive plantings in your 222-day season

Sow every 4.6 weeks. Last sowing by Sep 03 to harvest before frost.

For a dedicated fall crop, sow by Aug 24.

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 Dill

Dill 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 Dill 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.

Dill 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.

Dill needs ~875 GDD — county provides 3,885 GDD Excellent fit

Dill Planting Timeline โ€” Snohomish County, WA

Dill Planting Calendar

Activity When Date Range
Start Indoors February 18 Feb 18 โ€“ Mar 4
Transplant Outdoors March 18 Mar 18 โ€“ Apr 1
Direct Sow March 11 Mar 11 โ€“ Apr 1
Harvest April 29 Apr 29 โ€“ Jul 1
Fall Sowing August 24 Aug 24 โ€“ Sep 7

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors Transplant Outdoors Direct Sow
April Transplant Outdoors Direct Sow Harvest
May Harvest
June Harvest
July Harvest
August Fall Sowing
September Fall Sowing
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

40โ€“60 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

222 days in Snohomish County

Growing Tips for Dill in Snohomish County

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

Your generous 222.0-day season in Snohomish County allows multiple plantings of Dill. Sow every 20.0 days for continuous harvest.

Common pests for Dill in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow in spring as dill has a taproot and dislikes transplanting. Succession sow for continuous leaf harvest. Allow some plants to flower for seeds and to attract beneficial insects.

Companion Planting

Good Companions

Avoid Planting Near

  • Carrots
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Dill in Snohomish County, WA?

Snohomish County is in Zone 8a with an average last frost of March 25. Plan your Dill 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.