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When to Plant Celeriac in Deer Lodge County, MT

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.

Deer Lodge County, Montana is in USDA Zone 4a. The average last spring frost is June 15 and the first fall frost is September 7, giving you a growing season of approximately 84 days.

At an elevation of 6,928 feet, Deer Lodge County receives approximately 16.8 inches of rainfall annually with predominantly loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Celeriac to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Celeriac successfully. Mulch heavily to conserve soil moisture.

Deer Lodge County, MT (Zone 4a) Very short season
84 days
Last Spring Frost June 15
84 growing days
First Fall Frost September 7

Deer Lodge 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: Apr 28 Transplant: Jun 9 🍅 Harvest: Sep 22 – Oct 27
Recommended (50%) ✗ May not fit
Start indoors: May 4 Transplant: Jun 15 🍅 Harvest: Sep 28 – Nov 2
Safe Start (90%) ✗ May not fit
Start indoors: May 12 Transplant: Jun 23 🍅 Harvest: Oct 6 – Nov 10

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 Deer Lodge County

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

Soil pH

Your soil pH (6.6โ€“8.2) is more alkaline than Celeriac prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Celeriac.

How to Plant Celeriac

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.8″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 54 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Celeriac

Celeriac needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.

Month Celeriac Needs Rainfall You Supplement Action
Jan โ€” 1.2" 0" โ„๏ธ Dormant
Feb โ€” 0.9" 0" โ„๏ธ Dormant
Mar โ€” 1.4" 0" โ„๏ธ Dormant
Apr โ€” 1.9" 0" โ„๏ธ Dormant
May โ€” 1.9" 0" โ„๏ธ Dormant
Jun 3.9" 1.2" 2.7" ๐Ÿšฟ Regular watering
Jul 3.9" 1.4" 2.5" ๐Ÿšฟ Regular watering
Aug 3.9" 1.9" 2" ๐Ÿšฟ Regular watering
Sep 3.9" 1.3" 2.6" ๐Ÿšฟ Regular watering
Oct โ€” 1.6" 0" โ„๏ธ Dormant
Nov โ€” 1.1" 0" โ„๏ธ Dormant
Dec โ€” 0.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Junโ€“Sep in Deer Lodge County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Celeriac 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.

Celeriac needs ~1,182 GDD — county provides 903 GDD May not mature

Celeriac Planting Timeline โ€” Deer Lodge County, MT

Celeriac Planting Calendar

Activity When Date Range
Start Indoors May 4 May 4 โ€“ May 18
Transplant Outdoors June 15 Jun 15 โ€“ Jun 29
Direct Sow June 8 Jun 8 โ€“ Jun 29
Harvest September 28 Sep 28 โ€“ Nov 2
Fall Sowing June 15 Jun 15 โ€“ Jun 29

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 โ€”
August โ€”
September Harvest
October Harvest
November Harvest
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.9"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

100โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

84 days in Deer Lodge County

Growing Tips for Celeriac in Deer Lodge County

Direct sow Celeriac outdoors after June 15 in Deer Lodge County when soil has warmed and frost danger has passed.

Your 84.0-day growing season in Deer Lodge County is tight for Celeriac (100.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Celeriac in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

Deer Lodge County receives only 17" of rain annually. Celeriac needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Celeriac in Deer Lodge County, MT?

Deer Lodge County is in Zone 4a with an average last frost of June 15. Plan your Celeriac planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Deer Lodge County, MT?

Deer Lodge County, Montana is in USDA Hardiness Zone 4a. The average last spring frost is June 15 and first fall frost is September 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Deer Lodge County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

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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 Deer Lodge County, MT. Local conditions may vary. Last updated: April 2026.