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When to Plant Crocus in Cowlitz County, WA

Crocuses (Crocus spp.) are the heralds of spring — small, gem-like blooms that push up through frozen ground or even snow, often weeks before any other flower. Their compact corms naturalize readily in lawns, rock gardens, and borders, creating drifts of purple, white, and yellow that expand year after year. Bees prize early crocus as one of their first nectar and pollen sources of the season. The saffron crocus (C. sativus) blooms in fall and yields the world's most expensive spice.

Cowlitz County, Washington is in USDA Zone 8b. The average last spring frost is April 15 and the first fall frost is October 29, giving you a growing season of approximately 197 days.

At an elevation of 268 feet, Cowlitz County receives approximately 47.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Crocus during the growing season.

Bulb Blooms in Spring Pollinator-friendly Fragrant
Cowlitz County, WA (Zone 8b) Moderate season
197 days
Last Spring Frost April 15
197 growing days
First Fall Frost October 29
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Cowlitz County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.5

Drainage

Well Drained

Monthly Watering Guide for Crocus

Crocus needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Crocus Needs Rainfall You Supplement Action
Jan 7.2" 0" ❄️ Dormant
Feb 4.6" 0" ❄️ Dormant
Mar 5.1" 0" ❄️ Dormant
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 2.9" 1.4" 💧 Light watering
Jun 4.3" 2" 2.3" 🚿 Regular watering
Jul 4.3" 0.8" 3.5" 🚿 Regular watering
Aug 4.3" 0.9" 3.4" 🚿 Regular watering
Sep 4.3" 1.6" 2.7" 🚿 Regular watering
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 7.6" 0" ❄️ Dormant
Dec 7.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Cowlitz County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Crocus Planting Timeline — Cowlitz County, WA

Crocus Planting Calendar

Activity When Date Range
Bloom September 3 Sep 3 – Sep 24
Fall Sowing October 1 Oct 1 – Oct 15

Plant 4" deep · 3" apart · Rows 4" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June
July
August
September Bloom
October Fall Sowing
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

10–20 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 8b

📆 Growing Season

197 days in Cowlitz County

Growing Tips for Cowlitz County

Plant corms 3–4 inches deep and 2–3 inches apart in fall, when soil temperature drops below 60°F. Mass plantings (at least 25 corms per cluster) create the most visual impact. Plant in well-drained soil — corms rot in standing water. Crocus naturalize well under deciduous trees; the tree leafs out after crocus dormancy begins, so light competition is minimal. Squirrels and chipmunks dig corms — plant deeper (4 inches) or use wire mesh baskets in high-predation areas. Allow foliage to die back naturally before mowing lawns. In zones 8a–8b, plant in December with pre-chilled corms for best results.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Crocus in Cowlitz County, WA?

Cowlitz County is in Zone 8b with an average last frost of April 15. Plan your Crocus planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cowlitz County, WA?

Cowlitz County, Washington is in USDA Hardiness Zone 8b. The average last spring frost is April 15 and first fall frost is October 29.

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Your Cowlitz County Garden Planner — Free

A 22-page printable planner built for Cowlitz County (Zone 8b). 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 Cowlitz County, WA. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.