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When to Plant Garlic in Chaffee County, CO

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.

Chaffee County, Colorado is in USDA Zone 5a. The average last spring frost is June 16 and the first fall frost is September 7, giving you a growing season of approximately 83 days.

At an elevation of 7,788 feet, Chaffee County receives approximately 18.6 inches of rainfall annually with predominantly loam soil. Summer highs average 86ยฐF, providing good warmth for Garlic during the growing season. With low rainfall, drip irrigation is essential for growing Garlic successfully. Mulch heavily to conserve soil moisture.

Chaffee County, CO (Zone 5a) Very short season
83 days
Last Spring Frost June 16
83 growing days
First Fall Frost September 7

Chaffee County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Jun 10 🍅 Harvest: Sep 9 – Nov 25
Recommended (50%) ✗ May not fit
Transplant: Jun 16 🍅 Harvest: Sep 15 – Dec 1
Safe Start (90%) ✗ May not fit
Transplant: Jun 26 🍅 Harvest: Sep 25 – Dec 11

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 Chaffee County

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

Soil pH

Your soil pH (6.7โ€“7.6) overlaps with Garlic's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

The loam soil in Chaffee County is excellent for Garlic โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Garlic.

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
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.2" 0" โ„๏ธ Dormant
Mar โ€” 1.4" 0" โ„๏ธ Dormant
Apr โ€” 1.8" 0" โ„๏ธ Dormant
May โ€” 2.4" 0" โ„๏ธ Dormant
Jun 2.2" 1.4" 0.8" ๐Ÿ’ง Light watering
Jul 2.2" 1.8" 0.4" ๐Ÿ’ง Light watering
Aug 2.2" 1.9" 0.3" ๐Ÿ’ง Light watering
Sep 2.2" 1.4" 0.8" ๐Ÿ’ง Light watering
Oct โ€” 1.5" 0" โ„๏ธ Dormant
Nov โ€” 1.3" 0" โ„๏ธ Dormant
Dec โ€” 1.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Junโ€“Sep in Chaffee County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~2,392 GDD — county provides 1,203 GDD May not mature

Garlic Planting Timeline โ€” Chaffee County, CO

Garlic Planting Calendar

Activity When Date Range
Fall Sowing July 27 Jul 27 โ€“ Aug 10

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May โ€”
June โ€”
July Fall Sowing
August Fall Sowing
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

90โ€“240 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

83 days in Chaffee County

Growing Tips for Garlic in Chaffee County

Direct sow Garlic outdoors after June 16 in Chaffee County when soil has warmed and frost danger has passed.

Your 83.0-day growing season in Chaffee 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 Chaffee County, CO?

Chaffee County is in Zone 5a with an average last frost of June 16. Plan your Garlic planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Chaffee County, CO?

Chaffee County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 16 and first fall frost is September 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Chaffee County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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