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When to plant Feverfew in Washington County, CO

In Washington County, Feverfew is a single-season spring crop — there's no second fall window. Plant May 17–May 31 for an 90–120-day harvest, finishing well before the October 5 first frost.

When to Plant Feverfew in Washington County, CO

Feverfew is a bushy perennial herb with small daisy-like flowers and aromatic leaves. It has been used traditionally for headache relief and is a cheerful garden plant.

Washington County, Colorado is in USDA Zone 5b. The average last spring frost is May 10 and the first fall frost is October 5, giving you a growing season of approximately 148 days.

At an elevation of 6,091 feet, Washington County receives approximately 13 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Feverfew during the growing season. With low rainfall, drip irrigation is essential for growing Feverfew successfully. Mulch heavily to conserve soil moisture.

Washington County, CO (Zone 5b) Short season
148 days
Last Spring Frost May 10
148 growing days
First Fall Frost October 5

Washington County Soil Profile

Soil Type

Loam

Soil pH

6.8-8.3

Drainage

Well Drained

Monthly Watering Guide for Feverfew

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

Month Feverfew Needs Rainfall You Supplement Action
Jan 1" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1" 0" ❄️ Dormant
Apr 1.4" 0" ❄️ Dormant
May 4.3" 1.5" 2.8" 🚿 Regular watering
Jun 4.3" 1" 3.3" 🚿 Regular watering
Jul 4.3" 1.2" 3.1" 🚿 Regular watering
Aug 4.3" 1.5" 2.8" 🚿 Regular watering
Sep 4.3" 1.1" 3.2" 🚿 Regular watering
Oct 4.3" 1.1" 3.2" 🚿 Regular watering
Nov 0.9" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

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

Feverfew Planting Timeline — Washington County, CO

Feverfew Planting Calendar

Activity When Date Range
Transplant Outdoors May 17 May 17 – May 31
Harvest August 16 Aug 16 – Nov 1

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

148 days in Washington County

Growing Tips for Washington County

Start seeds indoors or direct sow on the soil surface. Deadhead regularly to prevent aggressive self-seeding. Divide clumps every 2-3 years to maintain vigor.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Feverfew in Washington County, CO?

Washington County is in Zone 5b with an average last frost of May 10. Plan your Feverfew planting based on this frost date — see the calendar above for exact timing.

What planting zone is Washington County, CO?

Washington County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 10 and first fall frost is October 5.

When should I plant Feverfew in Washington County, CO?

In Washington County, CO, plant Feverfew after the last frost (around May 10) and before the first frost (around October 5). Best results when soil holds above 50°F.

What growing zone is Washington County, CO for Feverfew?

Washington County sits in USDA Zone 5b. Feverfew grows reliably in zones 5a through 9b, so it's a good fit here.

Can Feverfew grow in Washington County's climate?

Yes — Feverfew grows well in Washington County's temperate climate. Washington County averages a 148-day frost-free season, with last frost around May 10 and first frost around October 5.

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Your Washington County Garden Planner — Free

A 22-page printable planner built for Washington County (Zone 5b). 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 Washington County, CO. Local conditions may vary. Last updated: July 2026.

Sources & credits

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