When to plant Celeriac in Franklin County, ID
Franklin County's spring Celeriac window runs May 5 through May 26. time plantings around the expected last-frost window for best survival. A second sowing from July 25 to August 8 extends the harvest into fall.
When to Plant Celeriac in Franklin County, ID
Your July planting checklist for Franklin County, Idaho
July rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Franklin County, Idaho.
-
Direct-sow celeriac for cool weather
Count back from your first frost (October 3) — these need to mature before the cold arrives.
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.
Franklin County, Idaho is in USDA Zone 6a. The average last spring frost is May 19 and the first fall frost is October 3, giving you a growing season of approximately 137 days.
At an elevation of 7,665 feet, Franklin County receives approximately 18.5 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Celeriac during the growing season. With low rainfall, drip irrigation is essential for growing Celeriac successfully. Mulch heavily to conserve soil moisture.
Franklin County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.7
Drainage
Well Drained
Celeriac Planting Risk Windows
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 Franklin County
How your county's soil matches Celeriac's growing requirements.
Soil pH
Your soil pH (6.7–7.7) is more alkaline than Celeriac prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Franklin County is excellent for Celeriac — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.6%). Annual compost additions will help Celeriac.
How to Plant Celeriac
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Celeriac Water Budget
Water stress score is 8/10 — 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 | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.1" | 0" | ❄️ Dormant |
| Mar | — | 1.5" | 0" | ❄️ Dormant |
| Apr | — | 2" | 0" | ❄️ Dormant |
| May | 3.9" | 1.9" | 2" | 🚿 Regular watering |
| Jun | 3.9" | 1.3" | 2.6" | 🚿 Regular watering |
| Jul | 3.9" | 1.8" | 2.1" | 🚿 Regular watering |
| Aug | 3.9" | 2" | 1.9" | 💧 Light watering |
| Sep | 3.9" | 1.6" | 2.3" | 🚿 Regular watering |
| Oct | 3.9" | 1.8" | 2.1" | 🚿 Regular watering |
| Nov | — | 1.2" | 0" | ❄️ Dormant |
| Dec | — | 1.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Franklin 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 Planting Timeline — Franklin County, ID
Celeriac Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 14 | Apr 14 – Apr 28 |
| Transplant Outdoors | May 19 | May 19 – Jun 2 |
| Direct Sow | May 5 | May 5 – May 26 |
| Harvest | September 1 | Sep 1 – Oct 6 |
| Fall Sowing | July 25 | Jul 25 – Aug 8 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors |
| July | Fall Sowing |
| August | Fall Sowing |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.9"/week · 1-2 times/week
📅 Days to Maturity
100–120 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 6a
📆 Growing Season
137 days in Franklin County
Growing Tips for Celeriac in Franklin County
Direct sow Celeriac outdoors after May 19 in Franklin County when soil has warmed and frost danger has passed.
Common pests for Celeriac in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.
Franklin County receives only 18" 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
Check more plant combinations with our Companion Planting Checker →
Celeriac in Other Locations
Frequently Asked Questions
When should I plant Celeriac in Franklin County, ID?
Franklin County is in Zone 6a with an average last frost of May 19. Plan your Celeriac planting based on this frost date — see the calendar above for exact timing.
What planting zone is Franklin County, ID?
Franklin County, Idaho is in USDA Hardiness Zone 6a. The average last spring frost is May 19 and first fall frost is October 3.
When should I plant Celeriac in Franklin County, ID?
In Franklin County, ID, plant Celeriac after the last frost (around May 19) and before the first frost (around October 3). Best results when soil holds above 50°F.
What growing zone is Franklin County, ID for Celeriac?
Franklin County sits in USDA Zone 6a. Celeriac grows reliably in zones 3a through 9b, so it's a good fit here.
Can Celeriac grow in Franklin County's climate?
Yes — Celeriac grows well in Franklin County's temperate climate. Franklin County averages a 137-day frost-free season, with last frost around May 19 and first frost around October 3.
Your Franklin County Garden Planner — Free
A 22-page printable planner built for Franklin County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.