Blog

When to Plant Celeriac in Lake County, CO

Celeriac is a celery relative grown for its knobby, flavorful root rather than its stalks. It has a rich celery flavor and is excellent roasted, mashed, or in soups.

Lake County, Colorado is in USDA Zone 4a. The average last spring frost is June 21 and the first fall frost is August 30, giving you a growing season of approximately 70 days.

At an elevation of 7,687 feet, Lake County receives approximately 21.2 inches of rainfall annually with predominantly loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Celeriac to ensure they mature before fall.

Lake County, CO (Zone 4a) Very short season
70 days
Last Spring Frost June 21
70 growing days
First Fall Frost August 30

Lake County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: May 5 Transplant: Jun 16 🍅 Harvest: Sep 29 – Nov 3
Recommended (50%) ✗ May not fit
Start indoors: May 10 Transplant: Jun 21 🍅 Harvest: Oct 4 – Nov 8
Safe Start (90%) ✗ May not fit
Start indoors: May 16 Transplant: Jun 27 🍅 Harvest: Oct 10 – Nov 14

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.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.3″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 170 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Celeriac needs ~1,348 GDD — county provides 857 GDD May not mature

Celeriac Planting Timeline โ€” Lake County, CO

Celeriac Planting Calendar

Activity When Date Range
Start Indoors May 10 May 10 โ€“ May 24
Transplant Outdoors June 21 Jun 21 โ€“ Jul 5
Direct Sow June 14 Jun 14 โ€“ Jul 5
Fall Sowing June 7 Jun 7 โ€“ Jun 21
Harvest October 4 Oct 4 โ€“ Nov 8

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Start Indoors
June Transplant Outdoors Direct Sow Fall Sowing
July Transplant Outdoors Direct Sow
August โ€”
September โ€”
October Harvest
November Harvest
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

High โ€” keep soil consistently moist

Days to Maturity

100โ€“120 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 4a

Growing Season

70 days

Growing Tips for Lake County

Start seeds indoors 10-12 weeks before last frost. Remove side roots as they develop to encourage a single large bulb. Harvest after a light frost for best flavor.

Companion Planting

Good Companions

Avoid Planting Near

  • Carrots
  • Parsnip

Level Up Your Garden

Frequently Asked Questions

When should I plant Celeriac in Lake County, CO?

Lake County is in Zone 4a with an average last frost of June 21. Plan your Celeriac planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Lake County, CO?

Lake County, Colorado is in USDA Hardiness Zone 4a. The average last spring frost is June 21 and first fall frost is August 30.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Lake County gardeners in Zone 4a 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 Lake County, CO. Local conditions may vary. Last updated: April 2026.