When to Plant Kohlrabi in Pinal County, AZ
Your May game plan for Pinal County, Arizona
Your garden in Pinal County, Arizona is working on a schedule, even when you're not. Here's where you should be this May.
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Basket week: kohlrabi
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
Kohlrabi is an unusual brassica that forms a swollen stem above ground with a mild, sweet turnip-like flavor. Both the bulb and tender leaves are edible.
Pinal County, Arizona is in USDA Zone 9a. The average last spring frost is February 23 and the first fall frost is November 27, giving you a growing season of approximately 277 days.
At an elevation of 3,959 feet, Pinal County receives approximately 15.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 98°F, so Kohlrabi may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Kohlrabi will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Kohlrabi successfully. Mulch heavily to conserve soil moisture.
Pinal County Soil Profile
Soil Type
Sandy Loam
Soil pH
7-8.6
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 Pinal County
How your county's soil matches Kohlrabi's growing requirements.
Soil pH
Your soil pH (7.0–8.6) is more alkaline than Kohlrabi prefers (6.0–7.5). Add sulfur or peat moss to lower pH.
Soil Texture
Sandy soil in Pinal County warms quickly in spring but drains fast. Kohlrabi will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Kohlrabi.
Organic Matter
Organic matter is low (0.7%). Add 2-3 inches of compost before planting Kohlrabi.
How to Plant Kohlrabi
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Kohlrabi
Sow every 5.1 weeks. Last sowing by Sep 23 to harvest before frost.
For a dedicated fall crop, sow by Oct 02.
Plant Water Budget
Water stress score is 10/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Kohlrabi
Kohlrabi needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.
| Month | Kohlrabi Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1" | 0" | ❄️ Dormant |
| Feb | 3" | 1" | 2" | 🚿 Regular watering |
| Mar | 3" | 0.8" | 2.2" | 🚿 Regular watering |
| Apr | 3" | 0.5" | 2.5" | 🚿 Regular watering |
| May | 3" | 0.3" | 2.7" | 🚿 Regular watering |
| Jun | 3" | 0.5" | 2.5" | 🚿 Regular watering |
| Jul | 3" | 3" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 3.5" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 1.9" | 1.1" | 💧 Light watering |
| Oct | 3" | 1.5" | 1.5" | 🚿 Regular watering |
| Nov | 3" | 0.8" | 2.2" | 🚿 Regular watering |
| Dec | — | 1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Feb–Nov in Pinal County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Kohlrabi 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.
Kohlrabi Planting Timeline — Pinal County, AZ
Kohlrabi Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 26 | Jan 26 – Feb 9 |
| Transplant Outdoors | February 23 | Feb 23 – Mar 9 |
| Direct Sow | February 2 | Feb 2 – Feb 23 |
| Harvest | April 13 | Apr 13 – May 18 |
| Fall Sowing | October 2 | Oct 2 – Oct 16 |
Plant 0.5" deep · 4" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors Transplant Outdoors Direct Sow |
| March | Transplant Outdoors |
| April | Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.7"/week · 2-3 times/week
📅 Days to Maturity
45–65 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 9a
📆 Growing Season
277 days in Pinal County
Growing Tips for Kohlrabi in Pinal County
Direct sow Kohlrabi outdoors after February 23 in Pinal County when soil has warmed and frost danger has passed.
Sandy soil in Pinal County dries quickly — mulch Kohlrabi with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
With summer highs reaching 98°F in Pinal County, provide afternoon shade for Kohlrabi and water deeply in the morning.
Your generous 278.0-day season in Pinal County allows multiple plantings of Kohlrabi. Sow every 22.0 days for continuous harvest.
Common pests for Kohlrabi 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 spring or fall. Harvest when bulbs are 2-3 inches in diameter for best texture and flavor. Larger bulbs may become woody and fibrous.
Companion Planting
Good Companions
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Check more plant combinations with our Companion Planting Checker →
Kohlrabi in Other Locations
Frequently Asked Questions
When should I plant Kohlrabi in Pinal County, AZ?
Pinal County is in Zone 9a with an average last frost of February 23. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.
What planting zone is Pinal County, AZ?
Pinal County, Arizona is in USDA Hardiness Zone 9a. The average last spring frost is February 23 and first fall frost is November 27.
Your Pinal County Garden Planner — Free
A 24-page printable planner built for Pinal County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.