When to Plant Celery in Pima County, AZ
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.
Pima County, Arizona is in USDA Zone 9a. The average last spring frost is April 1 and the first fall frost is November 9, giving you a growing season of approximately 222 days.
At an elevation of 4,327 feet, Pima County receives approximately 14.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 103°F, so Celery may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Celery will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Celery successfully. Mulch heavily to conserve soil moisture.
Pima County Soil Profile
Soil Type
Sandy Loam
Soil pH
6.8-8.3
Drainage
Well Drained
Plant 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 Pima County
How your county's soil matches Celery's growing requirements.
Soil pH
Your soil pH (6.8–8.3) is more alkaline than Celery prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
Sandy soil in Pima County warms quickly in spring but drains fast. Celery will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Celery is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.
Organic Matter
Organic matter is low (0.9%). Add 2-3 inches of compost before planting Celery.
How to Plant Celery
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Celery
Sow every 9.1 weeks. Last sowing by Jul 12 to harvest before frost.
For a dedicated fall crop, sow by Sep 14.
Plant Water Budget
Water stress score is 10/10 — consider drought-tolerant varieties and mulching
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 | — | 0.9" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | — | 0.7" | 0" | ❄️ Dormant |
| Apr | 5.6" | 0.5" | 5.1" | 🚿 Regular watering |
| May | 5.6" | 0.4" | 5.2" | 🚿 Regular watering |
| Jun | 5.6" | 0.5" | 5.1" | 🚿 Regular watering |
| Jul | 5.6" | 2.7" | 2.9" | 🚿 Regular watering |
| Aug | 5.6" | 3.2" | 2.4" | 💧 Light watering |
| Sep | 5.6" | 1.9" | 3.7" | 🚿 Regular watering |
| Oct | 5.6" | 1.4" | 4.2" | 🚿 Regular watering |
| Nov | 5.6" | 0.7" | 4.9" | 🚿 Regular watering |
| Dec | — | 0.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in Pima 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 — Pima County, AZ
Celery Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 4 | Mar 4 – Mar 18 |
| Transplant Outdoors | April 1 | Apr 1 – Apr 15 |
| Direct Sow | March 11 | Mar 11 – Apr 1 |
| Harvest | June 24 | Jun 24 – Aug 19 |
| Fall Sowing | September 14 | Sep 14 – Sep 28 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1.3"/week · 2-3 times/week
📅 Days to Maturity
80–120 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 9a
📆 Growing Season
222 days in Pima County
Growing Tips for Celery in Pima County
Direct sow Celery outdoors after April 01 in Pima County when soil has warmed and frost danger has passed.
Sandy soil in Pima County dries quickly — mulch Celery with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
With summer highs reaching 103°F in Pima County, provide afternoon shade for Celery and water deeply in the morning.
Common pests for Celery in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.
Pima County receives only 14" of rain annually. Celery 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. 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 Pima County, AZ?
Pima County is in Zone 9a with an average last frost of April 1. Plan your Celery planting based on this frost date — see the calendar above for exact timing.
What planting zone is Pima County, AZ?
Pima County, Arizona is in USDA Hardiness Zone 9a. The average last spring frost is April 1 and first fall frost is November 9.
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