When to Plant Turnip in Pima County, AZ
This month in Pima County, Arizona
Your garden in Pima County, Arizona is working on a schedule, even when you're not. Here's where you should be this May.
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Harvest turnip as they ripen
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
Turnips are a fast-growing cool-season root vegetable with edible roots and greens. Baby turnips are sweet and tender while mature ones are more pungent.
Pima County, Arizona is in USDA Zone 9b. 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 Turnip may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Turnip will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Turnip 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 Turnip's growing requirements.
Soil pH
Your soil pH (6.8–8.3) is more alkaline than Turnip 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. Turnip will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Turnip.
Organic Matter
Organic matter is low (0.9%). Add 2-3 inches of compost before planting Turnip.
How to Plant Turnip
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Turnip
Sow every 4.6 weeks. Last sowing by Sep 10 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 Turnip
Turnip needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Turnip Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 0.9" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | — | 0.7" | 0" | ❄️ Dormant |
| Apr | 4.3" | 0.5" | 3.8" | 🚿 Regular watering |
| May | 4.3" | 0.4" | 3.9" | 🚿 Regular watering |
| Jun | 4.3" | 0.5" | 3.8" | 🚿 Regular watering |
| Jul | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Aug | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Sep | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Oct | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Nov | 4.3" | 0.7" | 3.6" | 🚿 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.
Turnip 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.
Turnip Planting Timeline — Pima County, AZ
Turnip Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | March 11 | Mar 11 – Apr 1 |
| Harvest | April 22 | Apr 22 – May 27 |
| Fall Sowing | September 14 | Sep 14 – Sep 28 |
Plant 0.5" deep · 4" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Direct Sow |
| April | Direct Sow Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 2-3 times/week
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 9b
📆 Growing Season
222 days in Pima County
Growing Tips for Turnip in Pima County
Direct sow Turnip outdoors after April 01 in Pima County when soil has warmed and frost danger has passed.
Sandy soil in Pima County dries quickly — mulch Turnip 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 Turnip and water deeply in the morning.
Your generous 222.0-day season in Pima County allows multiple plantings of Turnip. Sow every 20.0 days for continuous harvest.
Common pests for Turnip in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow in early spring or late summer. Harvest when roots are 2-3 inches in diameter for best flavor. Both the roots and the greens are nutritious and edible.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Turnip in Other Locations
Frequently Asked Questions
When should I plant Turnip in Pima County, AZ?
Pima County is in Zone 9b with an average last frost of April 1. Plan your Turnip 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 9b. The average last spring frost is April 1 and first fall frost is November 9.
Your Pima County Garden Planner — Free
A 24-page printable planner built for Pima County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.