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When to Plant Garlic in Deschutes County, OR

Deschutes County, Oregon Zone 6b May

Deschutes County, Oregon gardeners: here's your May plan

Each item below is timed to Deschutes County, Oregon's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost June 15
Avg. first frost September 13
Soil temp (4") 62°F
Watering Moderate
Pest pressure Low
Daylight 14.5 hrs

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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.

Deschutes County, Oregon is in USDA Zone 6b. The average last spring frost is June 15 and the first fall frost is September 13, giving you a growing season of approximately 90 days.

At an elevation of 221 feet, Deschutes County receives approximately 54.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Garlic to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Garlic root diseases.

Deschutes County, OR (Zone 6b) Very short season
90 days
Last Spring Frost June 15
90 growing days
First Fall Frost September 13

Deschutes County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Jun 3 🍅 Harvest: Sep 2 – Dec 16
Recommended (50%) ✗ May not fit
Transplant: Jun 15 🍅 Harvest: Sep 14 – Dec 28
Safe Start (90%) ✓ Fits season (271 days to spare)
Transplant: Jun 26 🍅 Harvest: Sep 25 – Jan 8

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 Deschutes County

How your county's soil matches Garlic's growing requirements.

Soil pH

Your soil pH (5.4–6.2) is more acidic than Garlic prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Deschutes County is excellent for Garlic — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.0%) — Garlic will thrive.

How to Plant Garlic

1"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 6 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
2.6″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 7.6" 0" ❄️ Dormant
Feb 6.2" 0" ❄️ Dormant
Mar 4.9" 0" ❄️ Dormant
Apr 3.8" 0" ❄️ Dormant
May 3" 0" ❄️ Dormant
Jun 2.2" 2.5" 0" ✅ Rainfall sufficient
Jul 2.2" 1" 1.2" 🚿 Regular watering
Aug 2.2" 1" 1.2" 🚿 Regular watering
Sep 2.2" 2.2" 0" ✅ Rainfall sufficient
Oct 4.9" 0" ❄️ Dormant
Nov 7.8" 0" ❄️ Dormant
Dec 9.9" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Deschutes 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 needs ~1,774 GDD — county provides 967 GDD May not mature

Garlic Planting Timeline — Deschutes County, OR

Garlic Planting Calendar

Activity When Date Range
Fall Sowing August 2 Aug 2 – Aug 16

Plant 1" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June
July
August Fall Sowing
September
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

90 days in Deschutes County

Growing Tips for Garlic in Deschutes County

Direct sow Garlic outdoors after June 15 in Deschutes County when soil has warmed and frost danger has passed.

Your 90.0-day growing season in Deschutes 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

  • Peas
  • Green Beans
  • Asparagus

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Garlic in Deschutes County, OR?

Deschutes County is in Zone 6b with an average last frost of June 15. Plan your Garlic planting based on this frost date — see the calendar above for exact timing.

What planting zone is Deschutes County, OR?

Deschutes County, Oregon is in USDA Hardiness Zone 6b. The average last spring frost is June 15 and first fall frost is September 13.

🌱

Your Deschutes County Garden Planner — Free

A 24-page printable planner built for Deschutes 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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Deschutes County, OR. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.