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When to Plant Lavender in Clearwater County, ID

Lavender is a fragrant perennial herb with silvery foliage and purple flower spikes. It is prized for its essential oils, culinary uses, and ornamental beauty.

Clearwater County, Idaho is in USDA Zone 5b. The average last spring frost is May 17 and the first fall frost is September 28, giving you a growing season of approximately 134 days.

At an elevation of 7,800 feet, Clearwater County receives approximately 19 inches of rainfall annually with predominantly loam soil. Summer highs average 87ยฐF, providing good warmth for Lavender during the growing season. With low rainfall, drip irrigation is essential for growing Lavender successfully. Mulch heavily to conserve soil moisture.

Clearwater County, ID (Zone 5b) Short season
134 days
Last Spring Frost May 17
134 growing days
First Fall Frost September 28

Clearwater County Soil Profile

Soil Type

Loam

Soil pH

6.5-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 15 🍅 Harvest: Aug 14 – Oct 30
Recommended (50%) ✗ May not fit
Transplant: May 24 🍅 Harvest: Aug 23 – Nov 8
Safe Start (90%) ✗ May not fit
Transplant: Jun 17 🍅 Harvest: Sep 16 – Dec 2

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
0.6″/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

Lavender needs ~2,211 GDD — county provides 2,043 GDD Tight fit

Lavender Planting Timeline โ€” Clearwater County, ID

Lavender Planting Calendar

Activity When Date Range
Transplant Outdoors May 24 May 24 โ€“ Jun 7
Harvest August 23 Aug 23 โ€“ Nov 8

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

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

90โ€“200 days

Soil pH

6.5 โ€“ 8

USDA Zone

Zone 5b

Growing Season

134 days

Growing Tips for Clearwater County

Plant in well-drained, sandy soil. Avoid heavy mulching around the crown. Prune after flowering but do not cut into old wood. Lavender resents wet winter conditions.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Lavender in Clearwater County, ID?

Clearwater County is in Zone 5b with an average last frost of May 17. Plan your Lavender planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Clearwater County, ID?

Clearwater County, Idaho is in USDA Hardiness Zone 5b. The average last spring frost is May 17 and first fall frost is September 28.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Clearwater 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 Clearwater County, ID. Local conditions may vary. Last updated: April 2026.