Blog

When to Plant Celeriac in Mitchell, OR

Wheeler County, Oregon Zone 7a July

Wheeler County, Oregon gardeners: here's your July plan

We've pulled the most time-sensitive tasks for Wheeler County, Oregon this July and put them front and centre. Tackle them in order.

Avg. last frost May 23
Avg. first frost September 23
Soil temp (4") 74°F
Watering Critical
Pest pressure High
Daylight 15.1 hrs
  1. Direct-sow celeriac for cool weather

    A row cover ready in the garage extends your harvest by weeks once the nights turn cold.

Instant PDF download. No spam, unsubscribe any time.

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.

Mitchell, Oregon is in USDA Zone 7a. The average last spring frost is May 23 and the first fall frost is September 23, giving you a growing season of approximately 123 days.

At an elevation of 2,175 feet, Wheeler County receives approximately 22.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Celeriac to ensure they mature before fall.

Mitchell, OR (Zone 7a) Short season
123 days
Last Spring Frost May 23
123 growing days
First Fall Frost September 23

Mitchell Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.3

Drainage

Well Drained

Celeriac Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 11 Transplant: May 16 🍅 Harvest: Aug 29 – Oct 3
Recommended (50%) ✗ May not fit
Start indoors: Apr 18 Transplant: May 23 🍅 Harvest: Sep 5 – Oct 10
Safe Start (90%) ✗ May not fit
Start indoors: May 15 Transplant: Jun 19 🍅 Harvest: Oct 2 – Nov 6

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 Mitchell

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

Soil pH

Your soil pH (5.2–6.3) is more acidic than Celeriac prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.7%) — Celeriac will thrive.

How to Plant Celeriac

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Celeriac 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 133 gal / 100 sq ft

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 3" 0" ❄️ Dormant
Feb 2.3" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 1.6" 0" ❄️ Dormant
May 3.9" 1.5" 2.4" 🚿 Regular watering
Jun 3.9" 1" 2.9" 🚿 Regular watering
Jul 3.9" 0.4" 3.5" 🚿 Regular watering
Aug 3.9" 0.4" 3.5" 🚿 Regular watering
Sep 3.9" 0.8" 3.1" 🚿 Regular watering
Oct 2.1" 0" ❄️ Dormant
Nov 3.3" 0" ❄️ Dormant
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Wheeler County). Supplement amounts are based on average rainfall — 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" — 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.

Celeriac needs ~1,348 GDD — county provides 1,506 GDD Good fit

Celeriac Planting Timeline — Mitchell, OR

Celeriac Planting Calendar

Activity When Date Range
Start Indoors April 18 Apr 18 – May 2
Transplant Outdoors May 23 May 23 – Jun 6
Direct Sow May 9 May 9 – May 30
Harvest September 5 Sep 5 – Oct 10
Fall Sowing July 15 Jul 15 – Jul 29

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · Only during dry spells

📅 Days to Maturity

100–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7a

📆 Growing Season

123 days in Wheeler County

Growing Tips for Celeriac in Mitchell

Direct sow Celeriac outdoors after May 23 in Wheeler County when soil has warmed and frost danger has passed.

Your 123.0-day growing season in Wheeler 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.

Wheeler County receives only 23" of rain annually. Celeriac needs consistent moisture — 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 →

🌱

Your Wheeler County Garden Planner — Free

A 22-page printable planner built for Wheeler County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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