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When to Plant Catnip in Cassia County, ID

Catnip is a hardy perennial herb in the mint family known for its effect on cats. It also makes a calming tea and is a useful companion plant that repels some pests.

Cassia County, Idaho is in USDA Zone 5b. The average last spring frost is May 15 and the first fall frost is October 1, giving you a growing season of approximately 139 days.

At an elevation of 8,089 feet, Cassia County receives approximately 17.5 inches of rainfall annually with predominantly loam soil. Summer highs average 87ยฐF, providing good warmth for Catnip during the growing season. With low rainfall, drip irrigation is essential for growing Catnip successfully. Mulch heavily to conserve soil moisture.

Cassia County, ID (Zone 5b) Short season
139 days
Last Spring Frost May 15
139 growing days
First Fall Frost October 1

Cassia County Soil Profile

Soil Type

Loam

Soil pH

6.3-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (4 days to spare)
Transplant: May 16 🍅 Harvest: Jul 18 – Sep 19
Recommended (50%) ✓ Fits season (6 days to spare)
Transplant: May 22 🍅 Harvest: Jul 24 – Sep 25
Safe Start (90%) ✗ May not fit
Transplant: Jun 16 🍅 Harvest: Aug 18 – Oct 20

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.

Plant Water Budget

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

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Catnip needs ~1,068 GDD — county provides 2,119 GDD Excellent fit

Catnip Planting Timeline โ€” Cassia County, ID

Catnip Planting Calendar

Activity When Date Range
Transplant Outdoors May 22 May 22 โ€“ Jun 5
Harvest July 24 Jul 24 โ€“ Sep 25

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 Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

60โ€“80 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 5b

Growing Season

139 days

Growing Tips for Cassia County

Direct sow or start indoors. Catnip is very easy to grow and can become invasive. Harvest leaves before flowering for tea. Protect young plants from cats.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Catnip in Cassia County, ID?

Cassia County is in Zone 5b with an average last frost of May 15. Plan your Catnip planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Cassia County, ID?

Cassia County, Idaho is in USDA Hardiness Zone 5b. The average last spring frost is May 15 and first fall frost is October 1.

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Plan Your Garden with Confidence

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