When to Plant Garlic in Wasco County, OR
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.
Wasco County, Oregon is in USDA Zone 6b. The average last spring frost is April 23 and the first fall frost is October 12, giving you a growing season of approximately 172 days.
At an elevation of 432 feet, Wasco County receives approximately 35.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Garlic to ensure they mature before fall.
Wasco County Soil Profile
Soil Type
Silt Loam
Soil pH
5.2-6.3
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 Wasco County
How your county's soil matches Garlic's growing requirements.
Soil pH
Your soil pH (5.2–6.3) is more acidic than Garlic prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Wasco County is excellent for Garlic — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.2%) — Garlic will thrive.
How to Plant Garlic
Fall planting: Sow 6 weeks before your first frost date for a fall harvest.
Plant Water Budget
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 | — | 4.3" | 0" | ❄️ Dormant |
| Feb | — | 4" | 0" | ❄️ Dormant |
| Mar | — | 4" | 0" | ❄️ Dormant |
| Apr | 2.2" | 2.6" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 2.1" | 0.1" | 💧 Light watering |
| Jun | 2.2" | 1.5" | 0.7" | 💧 Light watering |
| Jul | 2.2" | 0.6" | 1.6" | 🚿 Regular watering |
| Aug | 2.2" | 0.7" | 1.5" | 🚿 Regular watering |
| Sep | 2.2" | 1.5" | 0.7" | 💧 Light watering |
| Oct | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Nov | — | 5.1" | 0" | ❄️ Dormant |
| Dec | — | 5.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Wasco 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 — Wasco County, OR
Garlic Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Fall Sowing | August 31 | Aug 31 – Sep 14 |
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 · Natural rainfall sufficient
📅 Days to Maturity
90–240 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 6b
📆 Growing Season
172 days in Wasco County
Growing Tips for Garlic in Wasco County
Direct sow Garlic outdoors after April 23 in Wasco County when soil has warmed and frost danger has passed.
Your 172.0-day growing season in Wasco 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
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Check more plant combinations with our Companion Planting Checker →
Garlic in Other Locations
Frequently Asked Questions
When should I plant Garlic in Wasco County, OR?
Wasco County is in Zone 6b with an average last frost of April 23. Plan your Garlic planting based on this frost date — see the calendar above for exact timing.
What planting zone is Wasco County, OR?
Wasco County, Oregon is in USDA Hardiness Zone 6b. The average last spring frost is April 23 and first fall frost is October 12.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Wasco County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.
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