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When to Plant Kohlrabi in Yuma County, AZ

Yuma County, Arizona Zone 10a May

Yuma County, Arizona gardeners: here's your May plan

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Yuma County, Arizona.

Avg. last frost February 10
Avg. first frost December 1
Soil temp (4") 66°F
Watering Critical
Pest pressure High
Daylight 13.7 hrs
  1. Collect kohlrabi at their peak

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

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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.

Yuma County, Arizona is in USDA Zone 10a. The average last spring frost is February 10 and the first fall frost is December 1, giving you a growing season of approximately 294 days.

At an elevation of 4,781 feet, Yuma County receives approximately 9.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 92°F, providing good warmth for Kohlrabi during the growing season. 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.

Yuma County, AZ (Zone 10a) Year-round
294 days
Last Spring Frost February 10
294 growing days
First Fall Frost December 1

Yuma County Soil Profile

Soil Type

Sandy Loam

Soil pH

6.9-8.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (212 days to spare)
Start indoors: Jan 6 Transplant: Feb 3 🍅 Harvest: Mar 24 – Apr 28
Recommended (50%) ✓ Fits season (210 days to spare)
Start indoors: Jan 13 Transplant: Feb 10 🍅 Harvest: Mar 31 – May 5
Safe Start (90%) ✓ Fits season (200 days to spare)
Start indoors: Feb 9 Transplant: Mar 9 🍅 Harvest: Apr 27 – Jun 1

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 Yuma County

How your county's soil matches Kohlrabi's growing requirements.

Soil pH

Your soil pH (6.9–8.4) is more alkaline than Kohlrabi prefers (6.0–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Yuma County warms quickly in spring but drains fast. Kohlrabi will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is low (0.8%). Add 2-3 inches of compost before planting Kohlrabi.

How to Plant Kohlrabi

0.5"
Planting Depth
4"
Between Plants
12"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Kohlrabi

7
successive plantings in your 294-day season

Sow every 5.1 weeks. Last sowing by Sep 27 to harvest before frost.

For a dedicated fall crop, sow by Oct 06.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.1″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 1,784 gal / 100 sq ft
Drought risk

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 0.6" 0" ❄️ Dormant
Feb 3" 0.5" 2.5" 🚿 Regular watering
Mar 3" 0.5" 2.5" 🚿 Regular watering
Apr 3" 0.3" 2.7" 🚿 Regular watering
May 3" 0.2" 2.8" 🚿 Regular watering
Jun 3" 0.3" 2.7" 🚿 Regular watering
Jul 3" 1.8" 1.2" 💧 Light watering
Aug 3" 1.9" 1.1" 💧 Light watering
Sep 3" 1.4" 1.6" 🚿 Regular watering
Oct 3" 0.8" 2.2" 🚿 Regular watering
Nov 3" 0.5" 2.5" 🚿 Regular watering
Dec 3" 0.6" 2.4" 🚿 Regular watering

Water needs are for active growing months only (Feb–Dec in Yuma 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 needs ~1,045 GDD — county provides 5,605 GDD Excellent fit

Kohlrabi Planting Timeline — Yuma County, AZ

Kohlrabi Planting Calendar

Activity When Date Range
Start Indoors January 13 Jan 13 – Jan 27
Transplant Outdoors February 10 Feb 10 – Feb 24
Direct Sow January 20 Jan 20 – Feb 10
Harvest March 31 Mar 31 – May 5
Fall Sowing October 6 Oct 6 – Oct 20

Plant 0.5" deep · 4" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors Direct Sow
February Transplant Outdoors Direct Sow
March Harvest
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 · 1-2 times/week

📅 Days to Maturity

45–65 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 10a

📆 Growing Season

294 days in Yuma County

Growing Tips for Kohlrabi in Yuma County

Direct sow Kohlrabi outdoors after February 10 in Yuma County when soil has warmed and frost danger has passed.

Sandy soil in Yuma County dries quickly — mulch Kohlrabi with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Your generous 295.0-day season in Yuma 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

Avoid Planting Near

  • Tomatoes
  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Kohlrabi in Yuma County, AZ?

Yuma County is in Zone 10a with an average last frost of February 10. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Yuma County, AZ?

Yuma County, Arizona is in USDA Hardiness Zone 10a. The average last spring frost is February 10 and first fall frost is December 1.

🌱

Your Yuma County Garden Planner — Free

A 24-page printable planner built for Yuma County (Zone 10a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Yuma County, AZ. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.