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When to plant Lavender in Humboldt County County,

In Humboldt County County, Lavender is a spring-only crop. Plant February 6–February 20 once soil hits 50°F.

When to Plant Lavender in Humboldt County, CA

Lavender
Humboldt County, California Zone 9b June

Your June game plan for Humboldt County, California

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost February 27
Avg. first frost November 28
Soil temp (4") 84°F
Watering Critical
Pest pressure High
Daylight 14.9 hrs
  1. Basket week: lavender

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

July will be here before you know it — start on
  • First harvests: lavender

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Lavender (Lavandula angustifolia) is a fragrant Mediterranean sub-shrub prized for its silver-gray foliage and intensely aromatic purple flower spikes. A classic companion for roses and an unmatched pollinator magnet, lavender thrives in the exact conditions that challenge many plants: poor, rocky, alkaline soil with excellent drainage and full sun. English lavender is the most cold-hardy species, reliably perennial in Zones 5–9. Fresh or dried flowers are widely used in sachets, essential oils, culinary applications, and dried arrangements.

Humboldt County, California is in USDA Zone 9b. The average last spring frost is February 27 and the first fall frost is November 28, giving you a growing season of approximately 274 days.

At an elevation of 148 feet, Humboldt County receives approximately 22.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 87°F, providing good warmth for Lavender during the growing season. Sandy soil warms quickly in spring — great for early planting — but Lavender will need more frequent watering and organic matter to retain nutrients.

Perennial Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting Fragrant
Humboldt County, CA (Zone 9b) Year-round
274 days
Last Spring Frost February 27
274 growing days
First Fall Frost November 28
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Humboldt County Soil Profile

Soil Type

Sandy Loam

Soil pH

6.2-6.8

Drainage

Well Drained

Lavender Planting Risk Windows

Early Start (70% safe) ✓ Fits season (150 days to spare)
Start indoors: Dec 19 Transplant: Jan 23 🌸 Bloom: Apr 3 – Jun 26
Recommended (50%) ✓ Fits season (141 days to spare)
Start indoors: Jan 2 Transplant: Feb 6 🌸 Bloom: Apr 17 – Jul 10
Safe Start (90%) ✓ Fits season (127 days to spare)
Start indoors: Feb 5 Transplant: Mar 12 🌸 Bloom: May 21 – Aug 13

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 Humboldt County

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

Soil pH

Your soil pH (6.2–6.8) overlaps with Lavender's range (6.5–7.5), though not a perfect match.

Soil Texture

Sandy soil in Humboldt County warms quickly in spring but drains fast. Lavender will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Lavender.

How to Plant Lavender

0.5"
Planting Depth
18"
Between Plants
24"
Between Rows

Lavender Water Budget

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

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 4.8" 0" ❄️ Dormant
Feb 1.3" 5" 0" ✅ Rainfall sufficient
Mar 1.3" 3.3" 0" ✅ Rainfall sufficient
Apr 1.3" 1.7" 0" ✅ Rainfall sufficient
May 1.3" 0.5" 0.8" 🚿 Regular watering
Jun 1.3" 0.1" 1.2" 🚿 Regular watering
Jul 1.3" 0" 1.3" 🚿 Regular watering
Aug 1.3" 0" 1.3" 🚿 Regular watering
Sep 1.3" 0.3" 1" 🚿 Regular watering
Oct 1.3" 0.8" 0.5" 💧 Light watering
Nov 1.3" 1.9" 0" ✅ Rainfall sufficient
Dec 3.7" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Humboldt County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~1,601 GDD — county provides 4,193 GDD Excellent fit

Lavender Planting Timeline — Humboldt County, CA

Lavender Planting Calendar

Activity When Date Range
Start Indoors January 2 Jan 2 – Jan 16
Transplant Outdoors February 6 Feb 6 – Feb 20
Bloom April 17 Apr 17 – Jul 10

Plant 0.5" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Transplant Outdoors
March
April Bloom
May Bloom
June Bloom
July Bloom
August
September
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.3"/week · Natural rainfall sufficient

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

274 days in Humboldt County

Growing Tips for Lavender in Humboldt County

Direct sow Lavender outdoors after February 27 in Humboldt County when soil has warmed and frost danger has passed.

Sandy soil in Humboldt County dries quickly — mulch Lavender with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

General growing tips

The single most important requirement for lavender success is excellent drainage — it will rot in heavy clay or wet winter soils before cold alone kills it. Amend with coarse sand or fine gravel if needed; raised beds work well in Zones 5–6. Start from rooted cuttings or transplants rather than seed for named cultivars. Transplant after last frost when soil is reliably warm (55°F+). Avoid rich or overly moist soils. Prune lightly after each flush of bloom, but never cut into old wood below the green growth zone — it will not regenerate from leafless woody stems. In Zones 5–6, mulch lightly with gravel (not bark/organic material which traps moisture) around the crown for winter protection. Year 2+ plants develop into full, mature shrubs with the most prolific bloom.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lavender in Humboldt County, CA?

Humboldt County is in Zone 9b with an average last frost of February 27. Plan your Lavender planting based on this frost date — see the calendar above for exact timing.

What planting zone is Humboldt County, CA?

Humboldt County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 27 and first fall frost is November 28.

When should I plant Lavender in Humboldt County County, ?

In Humboldt County County, , plant Lavender after the last frost (around February 27) and before the first frost (around November 28). Best results when soil holds above 50°F.

What growing zone is Humboldt County County, for Lavender?

Humboldt County County sits in USDA Zone 9b. Lavender grows reliably in zones 5a through 9b, so it's a good fit here.

Can Lavender grow in Humboldt County County's climate?

Yes — Lavender grows well in Humboldt County County's temperate climate. Humboldt County County averages a 275-day frost-free season, with last frost around February 27 and first frost around November 28.

🌱

Your Humboldt County Garden Planner — Free

A 22-page printable planner built for Humboldt County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Humboldt County, CA. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.