When to Plant Lavender in Pima County, AZ
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.
Pima County, Arizona is in USDA Zone 9a. The average last spring frost is April 1 and the first fall frost is November 9, giving you a growing season of approximately 222 days.
At an elevation of 4,327 feet, Pima County receives approximately 14.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 103°F, so Lavender may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Lavender will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Lavender successfully. Mulch heavily to conserve soil moisture.
Pima County Soil Profile
Soil Type
Sandy Loam
Soil pH
6.8-8.3
Drainage
Well Drained
Plant Planting Risk Windows
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 Pima County
How your county's soil matches Lavender's growing requirements.
Soil pH
Your soil pH (6.8–8.3) overlaps with Lavender's range (6.5–8.0), though not a perfect match.
Soil Texture
Sandy soil in Pima County warms quickly in spring but drains fast. Lavender will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Lavender.
Organic Matter
Organic matter is low (0.9%). Add 2-3 inches of compost before planting Lavender.
How to Plant Lavender
Plant Water Budget
Water stress score is 10/10 — 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 | — | 0.9" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | — | 0.7" | 0" | ❄️ Dormant |
| Apr | 1.3" | 0.5" | 0.8" | 🚿 Regular watering |
| May | 1.3" | 0.4" | 0.9" | 🚿 Regular watering |
| Jun | 1.3" | 0.5" | 0.8" | 🚿 Regular watering |
| Jul | 1.3" | 2.7" | 0" | ✅ Rainfall sufficient |
| Aug | 1.3" | 3.2" | 0" | ✅ Rainfall sufficient |
| Sep | 1.3" | 1.9" | 0" | ✅ Rainfall sufficient |
| Oct | 1.3" | 1.4" | 0" | ✅ Rainfall sufficient |
| Nov | 1.3" | 0.7" | 0.6" | 💧 Light watering |
| Dec | — | 0.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in Pima 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 Planting Timeline — Pima County, AZ
Lavender Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 8 | Apr 8 – Apr 22 |
| Harvest | July 8 | Jul 8 – Dec 9 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors |
| May | — |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | Harvest |
| December | Harvest |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.3"/week · Only during dry spells
📅 Days to Maturity
90–200 days
🧪 Soil pH
Needs 6.5–8 · Your soil: acceptable
🗺️ USDA Zone
Zone 9a
📆 Growing Season
222 days in Pima County
Growing Tips for Lavender in Pima County
Direct sow Lavender outdoors after April 01 in Pima County when soil has warmed and frost danger has passed.
Sandy soil in Pima County dries quickly — mulch Lavender with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
With summer highs reaching 103°F in Pima County, provide afternoon shade for Lavender and water deeply in the morning.
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 →
Lavender in Other Locations
Frequently Asked Questions
When should I plant Lavender in Pima County, AZ?
Pima County is in Zone 9a with an average last frost of April 1. Plan your Lavender planting based on this frost date — see the calendar above for exact timing.
What planting zone is Pima County, AZ?
Pima County, Arizona is in USDA Hardiness Zone 9a. The average last spring frost is April 1 and first fall frost is November 9.
Plan Your Garden with Confidence
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