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When to Plant Lavender in Napa County, CA

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.

Napa County, California is in USDA Zone 9a. The average last spring frost is February 26 and the first fall frost is November 26, giving you a growing season of approximately 273 days.

At an elevation of 449 feet, Napa County receives approximately 35 inches of rainfall annually with predominantly loam soil. Summer highs average 88ยฐF, providing good warmth for Lavender during the growing season.

Napa County, CA (Zone 9a) Year-round
273 days
Last Spring Frost February 26
273 growing days
First Fall Frost November 26

Napa County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (33 days to spare)
Transplant: Feb 17 🍅 Harvest: May 19 – Oct 20
Recommended (50%) ✓ Fits season (21 days to spare)
Transplant: Mar 5 🍅 Harvest: Jun 4 – Nov 5
Safe Start (90%) ✓ Fits season (7 days to spare)
Transplant: Apr 9 🍅 Harvest: Jul 9 – 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.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 332 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Lavender needs ~2,320 GDD — county provides 4,384 GDD Excellent fit

Lavender Planting Timeline โ€” Napa County, CA

Lavender Planting Calendar

Activity When Date Range
Transplant Outdoors March 5 Mar 5 โ€“ Mar 19
Harvest June 4 Jun 4 โ€“ Nov 5

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Transplant Outdoors
April โ€”
May โ€”
June Harvest
July Harvest
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 9a

Growing Season

273 days

Growing Tips for Napa 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 Napa County, CA?

Napa County is in Zone 9a with an average last frost of February 26. Plan your Lavender planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Napa County, CA?

Napa County, California is in USDA Hardiness Zone 9a. The average last spring frost is February 26 and first fall frost is November 26.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Napa County gardeners in Zone 9a 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 Napa County, CA. Local conditions may vary. Last updated: April 2026.