When to plant Feverfew in Cairo, IL
Cairo sits in cold Zone 7a. Plant Feverfew April 17–May 1 for the single annual harvest; the October 21 first frost closes the window.
When to Plant Feverfew in Cairo, IL
July in Alexander County, Illinois — your action list
Your garden in Alexander County, Illinois is working on a schedule, even when you're not. Here's where you should be this July.
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Start harvesting feverfew
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
Before August arrives, get these ready
- First harvests: feverfew
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.
Cairo, Illinois is in USDA Zone 7a. The average last spring frost is April 10 and the first fall frost is October 21, giving you a growing season of approximately 194 days.
At an elevation of 1,260 feet, Alexander County receives approximately 38.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Feverfew during the growing season.
Cairo Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-7
Drainage
Well Drained
Feverfew Planting Risk Windows
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 Cairo
How your county's soil matches Feverfew's growing requirements.
Soil pH
Your soil pH (5.9–7.0) overlaps with Feverfew's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Alexander County is excellent for Feverfew — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (4.0%). Annual compost additions will help Feverfew.
How to Plant Feverfew
Feverfew Water Budget
Water stress score is 6/10 — 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 | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 3" | 0" | ❄️ Dormant |
| Apr | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 5.1" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 4.8" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.4" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Alexander 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 Planting Timeline — Cairo, IL
Feverfew Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 17 | Apr 17 – May 1 |
| Harvest | July 17 | Jul 17 – Oct 2 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors |
| May | Transplant Outdoors |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | — |
| 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: acceptable
🗺️ USDA Zone
Zone 7a
📆 Growing Season
194 days in Alexander County
Growing Tips for Feverfew in Cairo
Direct sow Feverfew outdoors after April 10 in Alexander 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 →
Feverfew in Other Locations
When should I plant Feverfew in Cairo, IL?
In Cairo, IL, plant Feverfew after the last frost (around April 10) and before the first frost (around October 21). Best results when soil holds above 50°F.
What growing zone is Cairo, IL for Feverfew?
Cairo sits in USDA Zone 7a. Feverfew grows reliably in zones 5a through 9b, so it's a good fit here.
Can Feverfew grow in Cairo's climate?
Yes — Feverfew grows well in Cairo's temperate climate. Cairo averages a 194-day frost-free season, with last frost around April 10 and first frost around October 21.
Your Alexander County Garden Planner — Free
A 22-page printable planner built for Alexander County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.