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When to Plant Feverfew in Bannock County, ID

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.

Bannock County, Idaho is in USDA Zone 5a. The average last spring frost is May 23 and the first fall frost is September 24, giving you a growing season of approximately 124 days.

At an elevation of 5,637 feet, Bannock County receives approximately 13.1 inches of rainfall annually with predominantly loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Feverfew to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Feverfew successfully. Mulch heavily to conserve soil moisture.

Bannock County, ID (Zone 5a) Short season
124 days
Last Spring Frost May 23
124 growing days
First Fall Frost September 24

Bannock County Soil Profile

Soil Type

Loam

Soil pH

6.7-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 17 🍅 Harvest: Aug 16 – Nov 1
Recommended (50%) ✗ May not fit
Transplant: May 30 🍅 Harvest: Aug 29 – Nov 14
Safe Start (90%) ✗ May not fit
Transplant: Jun 25 🍅 Harvest: Sep 24 – Dec 10

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 Bannock County

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

Soil pH

Your soil pH (6.7โ€“8.1) is more alkaline than Feverfew prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). 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
0.4″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 75 gal / 100 sq ft
Drought risk

Water stress score is 8/10 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" 0" โ„๏ธ Dormant
Feb โ€” 0.8" 0" โ„๏ธ Dormant
Mar โ€” 1.1" 0" โ„๏ธ Dormant
Apr โ€” 1.4" 0" โ„๏ธ Dormant
May 2.2" 1.5" 0.7" ๐Ÿ’ง Light watering
Jun 2.2" 0.9" 1.3" ๐Ÿšฟ Regular watering
Jul 2.2" 1.1" 1.1" ๐Ÿšฟ Regular watering
Aug 2.2" 1.4" 0.8" ๐Ÿ’ง Light watering
Sep 2.2" 1" 1.2" ๐Ÿšฟ Regular watering
Oct โ€” 1" 0" โ„๏ธ Dormant
Nov โ€” 1" 0" โ„๏ธ Dormant
Dec โ€” 0.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Bannock 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 1,519 GDD Good fit

Feverfew Planting Timeline โ€” Bannock County, ID

Feverfew Planting Calendar

Activity When Date Range
Transplant Outdoors May 30 May 30 โ€“ Jun 13
Harvest August 29 Aug 29 โ€“ Nov 14

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

90โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

124 days in Bannock County

Growing Tips for Feverfew in Bannock County

Direct sow Feverfew outdoors after May 23 in Bannock County when soil has warmed and frost danger has passed.

Your 124.0-day growing season in Bannock County is tight for Feverfew (90.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

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

Bannock County receives only 13" of rain annually. Feverfew needs consistent moisture โ€” 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 Bannock County, ID?

Bannock County is in Zone 5a with an average last frost of May 23. Plan your Feverfew planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Bannock County, ID?

Bannock County, Idaho is in USDA Hardiness Zone 5a. The average last spring frost is May 23 and first fall frost is September 24.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Bannock County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

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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 Bannock County, ID. Local conditions may vary. Last updated: April 2026.