When to Plant Lavender in Blaine County, ID
May in Blaine County, Idaho — your action list
We've pulled the most time-sensitive tasks for Blaine County, Idaho this May and put them front and centre. Tackle them in order.
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Plant out lavender
Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.
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.
Blaine County, Idaho is in USDA Zone 5b. The average last spring frost is May 18 and the first fall frost is October 3, giving you a growing season of approximately 138 days.
At an elevation of 7,128 feet, Blaine County receives approximately 17.7 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Lavender to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Lavender successfully. Mulch heavily to conserve soil moisture.
Blaine County Soil Profile
Soil Type
Loam
Soil pH
6.7-8.4
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 Blaine County
How your county's soil matches Lavender's growing requirements.
Soil pH
Your soil pH (6.7–8.4) overlaps with Lavender's range (6.5–8.0), though not a perfect match.
Soil Texture
The loam soil in Blaine County is excellent for Lavender — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Lavender.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Lavender.
How to Plant Lavender
Plant Water Budget
Water stress score is 8/10 — 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 | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 0.9" | 0" | ❄️ Dormant |
| Mar | — | 1.5" | 0" | ❄️ Dormant |
| Apr | — | 1.7" | 0" | ❄️ Dormant |
| May | 1.3" | 1.9" | 0" | ✅ Rainfall sufficient |
| Jun | 1.3" | 1.2" | 0.1" | 💧 Light watering |
| Jul | 1.3" | 1.8" | 0" | ✅ Rainfall sufficient |
| Aug | 1.3" | 2.2" | 0" | ✅ Rainfall sufficient |
| Sep | 1.3" | 1.5" | 0" | ✅ Rainfall sufficient |
| Oct | 1.3" | 1.4" | 0" | ✅ Rainfall sufficient |
| Nov | — | 1.3" | 0" | ❄️ Dormant |
| Dec | — | 1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Blaine 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 — Blaine County, ID
Lavender Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 25 | May 25 – Jun 8 |
| Harvest | August 24 | Aug 24 – Nov 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 | — |
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: acceptable
🗺️ USDA Zone
Zone 5b
📆 Growing Season
138 days in Blaine County
Growing Tips for Lavender in Blaine County
Direct sow Lavender outdoors after May 18 in Blaine County when soil has warmed and frost danger has passed.
Your 138.0-day growing season in Blaine 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 Blaine County, ID?
Blaine County is in Zone 5b with an average last frost of May 18. Plan your Lavender planting based on this frost date — see the calendar above for exact timing.
What planting zone is Blaine County, ID?
Blaine County, Idaho is in USDA Hardiness Zone 5b. The average last spring frost is May 18 and first fall frost is October 3.
Your Blaine County Garden Planner — Free
A 24-page printable planner built for Blaine County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.