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When to Plant Feverfew in Piatt County, IL

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.

Piatt County, Illinois is in USDA Zone 5b. The average last spring frost is April 14 and the first fall frost is October 16, giving you a growing season of approximately 185 days.

At an elevation of 1,118 feet, Piatt County receives approximately 38.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Feverfew to ensure they mature before fall.

Piatt County, IL (Zone 5b) Moderate season
185 days
Last Spring Frost April 14
185 growing days
First Fall Frost October 16

Piatt County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (10 days to spare)
Transplant: Apr 16 🍅 Harvest: Jul 16 – Oct 1
Recommended (50%) ✓ Fits season (10 days to spare)
Transplant: Apr 21 🍅 Harvest: Jul 21 – Oct 6
Safe Start (90%) ✓ Fits season (16 days to spare)
Transplant: May 1 🍅 Harvest: Jul 31 – Oct 16

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 Piatt County

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

Soil pH

Your soil pH (6.0โ€“7.1) overlaps with Feverfew's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.0%) โ€” Feverfew will thrive.

How to Plant Feverfew

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

Plant Water Budget

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

Water stress score is 6/10 โ€” 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 โ€” 1.6" 0" โ„๏ธ Dormant
Feb โ€” 1.8" 0" โ„๏ธ Dormant
Mar โ€” 2.9" 0" โ„๏ธ Dormant
Apr 2.2" 4.2" 0" โœ… Rainfall sufficient
May 2.2" 4.7" 0" โœ… Rainfall sufficient
Jun 2.2" 4.6" 0" โœ… Rainfall sufficient
Jul 2.2" 4.5" 0" โœ… Rainfall sufficient
Aug 2.2" 3.7" 0" โœ… Rainfall sufficient
Sep 2.2" 3.3" 0" โœ… Rainfall sufficient
Oct 2.2" 2.7" 0" โœ… Rainfall sufficient
Nov โ€” 2.6" 0" โ„๏ธ Dormant
Dec โ€” 2.2" 0" โ„๏ธ Dormant

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

Feverfew needs ~1,286 GDD — county provides 2,266 GDD Excellent fit

Feverfew Planting Timeline โ€” Piatt County, IL

Feverfew Planting Calendar

Activity When Date Range
Transplant Outdoors April 21 Apr 21 โ€“ May 5
Harvest July 21 Jul 21 โ€“ Oct 6

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 Transplant Outdoors
June โ€”
July Harvest
August Harvest
September Harvest
October Harvest
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

90โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 5b

๐Ÿ“† Growing Season

185 days in Piatt County

Growing Tips for Feverfew in Piatt County

Direct sow Feverfew outdoors after April 14 in Piatt 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.

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 Piatt County, IL?

Piatt County is in Zone 5b with an average last frost of April 14. Plan your Feverfew planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Piatt County, IL?

Piatt County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 14 and first fall frost is October 16.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Piatt County gardeners in Zone 5b 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 Piatt County, IL. Local conditions may vary. Last updated: April 2026.