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When to Plant Sunchoke in Gunnison County, CO

Gunnison County, Colorado Zone 5a May

May in Gunnison County, Colorado — your action list

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost June 12
Avg. first frost September 10
Soil temp (4") 34°F
Watering High
Pest pressure Low
Daylight 14.1 hrs
Looking ahead to June
  • Transplants going out: sunchoke

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Sunchokes (Jerusalem artichokes) are a native sunflower relative grown for their knobby, nutty-flavored tubers. They are extremely productive and nearly impossible to eradicate.

Gunnison County, Colorado is in USDA Zone 5a. The average last spring frost is June 12 and the first fall frost is September 10, giving you a growing season of approximately 90 days.

At an elevation of 7,435 feet, Gunnison County receives approximately 17.9 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Sunchoke to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Sunchoke successfully. Mulch heavily to conserve soil moisture.

Gunnison County, CO (Zone 5a) Very short season
90 days
Last Spring Frost June 12
90 growing days
First Fall Frost September 10

Gunnison County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Jun 12 🍅 Harvest: Oct 2 – Nov 27
Recommended (50%) ✗ May not fit
Transplant: Jun 26 🍅 Harvest: Oct 16 – Dec 11
Safe Start (90%) ✗ May not fit
Transplant: Jul 9 🍅 Harvest: Oct 29 – Dec 24

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 Gunnison County

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

Soil pH

Your soil pH (6.5–7.9) overlaps with Sunchoke's range (6.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Gunnison County is excellent for Sunchoke — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Sunchoke.

How to Plant Sunchoke

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 158 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Sunchoke

Sunchoke needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Sunchoke Needs Rainfall You Supplement Action
Jan 1.2" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 2" 0" ❄️ Dormant
May 2.2" 0" ❄️ Dormant
Jun 4.3" 1.3" 3" 🚿 Regular watering
Jul 4.3" 1.7" 2.6" 🚿 Regular watering
Aug 4.3" 1.6" 2.7" 🚿 Regular watering
Sep 4.3" 1.5" 2.8" 🚿 Regular watering
Oct 1.4" 0" ❄️ Dormant
Nov 1.2" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Gunnison County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Sunchoke 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.

Sunchoke needs ~1,592 GDD — county provides 1,102 GDD May not mature

Sunchoke Planting Timeline — Gunnison County, CO

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors June 26 Jun 26 – Jul 10
Harvest October 16 Oct 16 – Dec 11

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June Transplant Outdoors
July Transplant Outdoors
August
September
October Harvest
November Harvest
December Harvest

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

110–150 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

90 days in Gunnison County

Growing Tips for Sunchoke in Gunnison County

Direct sow Sunchoke outdoors after June 12 in Gunnison County when soil has warmed and frost danger has passed.

Your 90.0-day growing season in Gunnison County is tight for Sunchoke (110.0-150.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Sunchoke in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

Gunnison County receives only 18" of rain annually. Sunchoke needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Plant tubers 4 inches deep in early spring. Contain plants with barriers as they spread aggressively. Harvest after frost or leave in ground and dig as needed through winter.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunchoke in Gunnison County, CO?

Gunnison County is in Zone 5a with an average last frost of June 12. Plan your Sunchoke planting based on this frost date — see the calendar above for exact timing.

What planting zone is Gunnison County, CO?

Gunnison County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 12 and first fall frost is September 10.

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Your Gunnison County Garden Planner — Free

A 24-page printable planner built for Gunnison County (Zone 5a). 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 Gunnison County, CO. 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.