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When to Plant Feverfew in Arapahoe County, CO

Arapahoe County, Colorado Zone 6a May

May to-do list for Arapahoe County, Colorado

Each item below is timed to Arapahoe County, Colorado's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 10
Avg. first frost October 7
Soil temp (4") 37°F
Watering High
Pest pressure Low
Daylight 14.2 hrs
  1. Set out feverfew seedlings

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

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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.

Arapahoe County, Colorado is in USDA Zone 6a. The average last spring frost is May 10 and the first fall frost is October 7, giving you a growing season of approximately 150 days.

At an elevation of 7,205 feet, Arapahoe County receives approximately 21.4 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Feverfew during the growing season.

Arapahoe County, CO (Zone 6a) Moderate season
150 days
Last Spring Frost May 10
150 growing days
First Fall Frost October 7

Arapahoe County Soil Profile

Soil Type

Loam

Soil pH

6.2-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 8 🍅 Harvest: Aug 7 – Oct 23
Recommended (50%) ✗ May not fit
Transplant: May 17 🍅 Harvest: Aug 16 – Nov 1
Safe Start (90%) ✗ May not fit
Transplant: May 29 🍅 Harvest: Aug 28 – Nov 13

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 Arapahoe County

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

Soil pH

Your soil pH (6.2–8.3) is more alkaline than Feverfew prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

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

How to Plant Feverfew

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

Plant Water Budget

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

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Feverfew

Feverfew 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 Feverfew Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 2.2" 0" ❄️ Dormant
May 2.2" 2.5" 0" ✅ Rainfall sufficient
Jun 2.2" 1.4" 0.8" 💧 Light watering
Jul 2.2" 2" 0.2" 💧 Light watering
Aug 2.2" 2.4" 0" ✅ Rainfall sufficient
Sep 2.2" 1.9" 0.3" 💧 Light watering
Oct 2.2" 1.7" 0.5" 💧 Light watering
Nov 1.5" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

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

Feverfew 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.

Feverfew needs ~1,601 GDD — county provides 2,287 GDD Excellent fit

Feverfew Planting Timeline — Arapahoe 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

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

150 days in Arapahoe County

Growing Tips for Feverfew in Arapahoe County

Direct sow Feverfew outdoors after May 10 in Arapahoe County when soil has warmed and frost danger has passed.

Common pests for Feverfew in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

Arapahoe County receives only 21" of rain annually. Feverfew needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

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 Arapahoe County, CO?

Arapahoe County is in Zone 6a 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 Arapahoe County, CO?

Arapahoe County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 10 and first fall frost is October 7.

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Your Arapahoe County Garden Planner — Free

A 24-page printable planner built for Arapahoe County (Zone 6a). 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 Arapahoe County, CO. 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.