When to Plant Lavender in Lewis County, ID
May to-do list for Lewis County, Idaho
Your Lewis County, Idaho garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
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Transplant lavender outside
Frost risk is low now in Lewis County, Idaho. If you've been covering beds overnight, you can stop.
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.
Lewis County, Idaho is in USDA Zone 6b. The average last spring frost is May 20 and the first fall frost is September 23, giving you a growing season of approximately 126 days.
At an elevation of 4,861 feet, Lewis County receives approximately 13.5 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, 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.
Lewis County Soil Profile
Soil Type
Loam
Soil pH
6.7-8
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 Lewis County
How your county's soil matches Lavender's growing requirements.
Soil pH
Your soil pH (6.7–8.0) is within Lavender's preferred range (6.5–8.0).
Soil Texture
The loam soil in Lewis County is excellent for Lavender — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Lavender.
How to Plant Lavender
Plant Water Budget
Water stress score is 6/10 — 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 | — | 1" | 0" | ❄️ Dormant |
| Feb | — | 0.7" | 0" | ❄️ Dormant |
| Mar | — | 1.1" | 0" | ❄️ Dormant |
| Apr | — | 1.4" | 0" | ❄️ Dormant |
| May | 1.3" | 1.7" | 0" | ✅ Rainfall sufficient |
| Jun | 1.3" | 0.8" | 0.5" | 💧 Light watering |
| Jul | 1.3" | 1.2" | 0.1" | 💧 Light watering |
| Aug | 1.3" | 1.4" | 0" | ✅ Rainfall sufficient |
| Sep | 1.3" | 1.2" | 0.1" | 💧 Light watering |
| Oct | — | 1.3" | 0" | ❄️ Dormant |
| Nov | — | 0.8" | 0" | ❄️ Dormant |
| Dec | — | 0.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Lewis 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 — Lewis County, ID
Lavender Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 27 | May 27 – Jun 10 |
| Harvest | August 26 | Aug 26 – Dec 9 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | Transplant Outdoors |
| July | — |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | Harvest |
| December | Harvest |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.3"/week · Natural rainfall sufficient
📅 Days to Maturity
90–200 days
🧪 Soil pH
Needs 6.5–8 · Your soil: ideal
🗺️ USDA Zone
Zone 6b
📆 Growing Season
126 days in Lewis County
Growing Tips for Lavender in Lewis County
Direct sow Lavender outdoors after May 20 in Lewis County when soil has warmed and frost danger has passed.
Your 126.0-day growing season in Lewis 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 →
Lavender in Other Locations
Frequently Asked Questions
When should I plant Lavender in Lewis County, ID?
Lewis County is in Zone 6b with an average last frost of May 20. Plan your Lavender planting based on this frost date — see the calendar above for exact timing.
What planting zone is Lewis County, ID?
Lewis County, Idaho is in USDA Hardiness Zone 6b. The average last spring frost is May 20 and first fall frost is September 23.
Your Lewis County Garden Planner — Free
A 24-page printable planner built for Lewis County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.