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When to Plant Lavender in Owyhee 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.

Owyhee County, Idaho is in USDA Zone 6a. The average last spring frost is June 9 and the first fall frost is September 20, giving you a growing season of approximately 103 days.

At an elevation of 4,621 feet, Owyhee County receives approximately 18.1 inches of rainfall annually with predominantly loam soil. Summer highs average 90ยฐF, 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.

Owyhee County, ID (Zone 6a) Short season
103 days
Last Spring Frost June 9
103 growing days
First Fall Frost September 20

Owyhee County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Jun 8 🍅 Harvest: Sep 7 – Dec 21
Recommended (50%) ✗ May not fit
Transplant: Jun 16 🍅 Harvest: Sep 15 – Dec 29
Safe Start (90%) ✓ Fits season (282 days to spare)
Transplant: Jun 26 🍅 Harvest: Sep 25 – Jan 8

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 Owyhee County

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

Soil pH

Your soil pH (6.3โ€“7.8) overlaps with Lavender's range (6.5โ€“8.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Lavender.

How to Plant Lavender

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

Plant Water Budget

Plant needs
0.3″/week
Rainfall provides
0.7″/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

Monthly Watering Guide for Lavender

Lavender needs approximately 0.3 inches of water per week (1.3" per month). Here's how your county's rainfall compares month by month.

Month Lavender Needs Rainfall You Supplement Action
Jan โ€” 1.1" 0" โ„๏ธ Dormant
Feb โ€” 1.1" 0" โ„๏ธ Dormant
Mar โ€” 1.7" 0" โ„๏ธ Dormant
Apr โ€” 2" 0" โ„๏ธ Dormant
May โ€” 2.3" 0" โ„๏ธ Dormant
Jun 1.3" 1.4" 0" โœ… Rainfall sufficient
Jul 1.3" 1.8" 0" โœ… Rainfall sufficient
Aug 1.3" 1.7" 0" โœ… Rainfall sufficient
Sep 1.3" 1.3" 0" โœ… Rainfall sufficient
Oct โ€” 1.6" 0" โ„๏ธ Dormant
Nov โ€” 1.2" 0" โ„๏ธ Dormant
Dec โ€” 1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Junโ€“Sep in Owyhee County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Lavender 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.

Lavender needs ~2,538 GDD — county provides 1,802 GDD May not mature

Lavender Planting Timeline โ€” Owyhee County, ID

Lavender Planting Calendar

Activity When Date Range
Transplant Outdoors June 16 Jun 16 โ€“ Jun 30
Harvest September 15 Sep 15 โ€“ Dec 29

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.3"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

90โ€“200 days

๐Ÿงช Soil pH

Needs 6.5โ€“8 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

103 days in Owyhee County

Growing Tips for Lavender in Owyhee County

Direct sow Lavender outdoors after June 09 in Owyhee County when soil has warmed and frost danger has passed.

Your 103.0-day growing season in Owyhee County is tight for Lavender (90.0-200.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lavender in Owyhee County, ID?

Owyhee County is in Zone 6a with an average last frost of June 9. Plan your Lavender planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Owyhee County, ID?

Owyhee County, Idaho is in USDA Hardiness Zone 6a. The average last spring frost is June 9 and first fall frost is September 20.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Owyhee County gardeners in Zone 6a 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 Owyhee County, ID. Local conditions may vary. Last updated: April 2026.