When to Plant Garlic in Blaine County, ID
May in the garden — Blaine County, Idaho
Each item below is timed to Blaine County, Idaho's frost dates and soil temperatures. Skip nothing, stress about nothing.
Garlic is a pungent allium planted in fall and harvested the following summer. Hardneck varieties produce edible flower stalks (scapes) and are more cold-hardy.
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 Garlic to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Garlic 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 Garlic's growing requirements.
Soil pH
Your soil pH (6.7–8.4) is more alkaline than Garlic prefers (6.0–7.5). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Blaine County is excellent for Garlic — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Garlic.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Garlic.
How to Plant Garlic
Fall planting: Sow 6 weeks before your first frost date for a fall harvest.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Garlic
Garlic needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.
| Month | Garlic 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 | 2.2" | 1.9" | 0.3" | 💧 Light watering |
| Jun | 2.2" | 1.2" | 1" | 💧 Light watering |
| Jul | 2.2" | 1.8" | 0.4" | 💧 Light watering |
| Aug | 2.2" | 2.2" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 1.5" | 0.7" | 💧 Light watering |
| Oct | 2.2" | 1.4" | 0.8" | 💧 Light watering |
| 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.
Garlic 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.
Garlic Planting Timeline — Blaine County, ID
Garlic Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Fall Sowing | August 22 | Aug 22 – Sep 5 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | — |
| July | — |
| August | Fall Sowing |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Only during dry spells
📅 Days to Maturity
90–240 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5b
📆 Growing Season
138 days in Blaine County
Growing Tips for Garlic in Blaine County
Direct sow Garlic 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 Garlic (90.0-240.0 days to maturity). Start indoors and choose early-maturing varieties.
Common pests for Garlic in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.
General growing tips
Plant individual cloves pointed end up in fall, 6 weeks before ground freezes. Mulch heavily with straw. Harvest when lower leaves begin to brown but 5-6 green leaves remain.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Garlic in Other Locations
Frequently Asked Questions
When should I plant Garlic in Blaine County, ID?
Blaine County is in Zone 5b with an average last frost of May 18. Plan your Garlic 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.