When to plant Celery in Hardin County, IA
In Hardin County, plant Celery in spring between April 14 and May 5, once soil temps hold above 50°F. Hardin County's last frost averages April 28, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between July 31 and August 14 — roughly 80–120 days before the first frost on October 9.
When to Plant Celery in Hardin County, IA
Your June gardening checklist
Here's what deserves your attention in Hardin County, Iowa this month. Everything below is tailored to Zone 5a and timed around your local frost dates.
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Get celery seeds going inside
Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.
To set up a strong July, finish these tasks
- First harvests: celery
- Fall sowing: celery
Celery is a marshland plant that requires consistent moisture and cool temperatures to produce crisp, flavorful stalks. It is a rewarding but demanding garden crop.
Hardin County, Iowa is in USDA Zone 5a. The average last spring frost is April 28 and the first fall frost is October 9, giving you a growing season of approximately 164 days.
At an elevation of 507 feet, Hardin County receives approximately 40.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Celery to ensure they mature before fall.
Hardin County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-6.9
Drainage
Well Drained
Celery 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 Hardin County
How your county's soil matches Celery's growing requirements.
Soil pH
Your soil pH (5.8–6.9) overlaps with Celery's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Hardin County is excellent for Celery — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.1%) — Celery will thrive.
How to Plant Celery
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Celery
Sow every 9.1 weeks. Last sowing by Jun 11 to harvest before frost.
For a dedicated fall crop, sow by Jul 31.
Celery Water Budget
Monthly Watering Guide for Celery
Celery needs approximately 1.3 inches of water per week (5.6" per month). Here's how your county's rainfall compares month by month.
| Month | Celery Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.9" | 0" | ❄️ Dormant |
| Mar | — | 3.1" | 0" | ❄️ Dormant |
| Apr | 5.6" | 4.1" | 1.5" | 💧 Light watering |
| May | 5.6" | 4.1" | 1.5" | 💧 Light watering |
| Jun | 5.6" | 4.4" | 1.2" | 💧 Light watering |
| Jul | 5.6" | 5.1" | 0.5" | 💧 Light watering |
| Aug | 5.6" | 3.9" | 1.7" | 💧 Light watering |
| Sep | 5.6" | 3.7" | 1.9" | 💧 Light watering |
| Oct | 5.6" | 3.4" | 2.2" | 💧 Light watering |
| Nov | — | 2.9" | 0" | ❄️ Dormant |
| Dec | — | 2.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Hardin County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Celery 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.
Celery Planting Timeline — Hardin County, IA
Celery Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 24 | Mar 24 – Apr 7 |
| Transplant Outdoors | April 28 | Apr 28 – May 12 |
| Direct Sow | April 14 | Apr 14 – May 5 |
| Harvest | July 21 | Jul 21 – Sep 15 |
| Fall Sowing | July 31 | Jul 31 – Aug 14 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Fall Sowing Harvest |
| August | Fall Sowing Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1.3"/week · Only during dry spells
📅 Days to Maturity
80–120 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 5a
📆 Growing Season
164 days in Hardin County
Growing Tips for Celery in Hardin County
Direct sow Celery outdoors after April 28 in Hardin County when soil has warmed and frost danger has passed.
Common pests for Celery in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 10-12 weeks before last frost. Keep soil consistently moist and never let it dry out. Blanch stalks by mounding soil or using collars for milder flavor.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Celery in Other Locations
Frequently Asked Questions
When should I plant Celery in Hardin County, IA?
Hardin County is in Zone 5a with an average last frost of April 28. Plan your Celery planting based on this frost date — see the calendar above for exact timing.
What planting zone is Hardin County, IA?
Hardin County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 28 and first fall frost is October 9.
When should I plant Celery in Hardin County, IA?
In Hardin County, IA, plant Celery after the last frost (around April 28) and before the first frost (around October 9). Best results when soil holds above 50°F.
What growing zone is Hardin County, IA for Celery?
Hardin County sits in USDA Zone 5a. Celery grows reliably in zones 2a through 10b, so it's a good fit here.
Can Celery grow in Hardin County's climate?
Yes — Celery grows well in Hardin County's temperate climate. Hardin County averages a 164-day frost-free season, with last frost around April 28 and first frost around October 9.
Your Hardin County Garden Planner — Free
A 22-page printable planner built for Hardin 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.