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When to Plant Kohlrabi in Yavapai County, AZ

Yavapai County, Arizona Zone 8b May

This month in Yavapai County, Arizona

Your garden in Yavapai County, Arizona is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 9
Avg. first frost November 5
Soil temp (4") 60°F
Watering Critical
Pest pressure Moderate
Daylight 13.8 hrs
  1. Sow kohlrabi in trays indoors

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

  2. Harvest kohlrabi as they ripen

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

A few tasks this May that'll pay off in June
  • First harvests: kohlrabi

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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.

Yavapai County, Arizona is in USDA Zone 8b. The average last spring frost is April 9 and the first fall frost is November 5, giving you a growing season of approximately 210 days.

At an elevation of 3,732 feet, Yavapai County receives approximately 14.2 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 101°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.

Yavapai County, AZ (Zone 8b) Long season
210 days
Last Spring Frost April 9
210 growing days
First Fall Frost November 5

Yavapai County Soil Profile

Soil Type

Sandy Loam

Soil pH

7-8.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (131 days to spare)
Start indoors: Feb 19 Transplant: Mar 26 🍅 Harvest: May 14 – Jun 18
Recommended (50%) ✓ Fits season (126 days to spare)
Start indoors: Mar 5 Transplant: Apr 9 🍅 Harvest: May 28 – Jul 2
Safe Start (90%) ✓ Fits season (124 days to spare)
Start indoors: Apr 3 Transplant: May 8 🍅 Harvest: Jun 26 – Jul 31

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 Yavapai County

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

Soil pH

Your soil pH (7.0–8.5) is more alkaline than Kohlrabi prefers (6.0–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Yavapai 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

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Kohlrabi

5
successive plantings in your 210-day season

Sow every 5.1 weeks. Last sowing by Sep 01 to harvest before frost.

For a dedicated fall crop, sow by Aug 27.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.3″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,404 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 1" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 0.9" 0" ❄️ Dormant
Apr 3" 0.5" 2.5" 🚿 Regular watering
May 3" 0.4" 2.6" 🚿 Regular watering
Jun 3" 0.4" 2.6" 🚿 Regular watering
Jul 3" 2.8" 0.2" 💧 Light watering
Aug 3" 2.7" 0.3" 💧 Light watering
Sep 3" 1.7" 1.3" 💧 Light watering
Oct 3" 1.1" 1.9" 🚿 Regular watering
Nov 3" 0.8" 2.2" 🚿 Regular watering
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Yavapai 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 ~1,416 GDD — county provides 5,407 GDD Excellent fit

Kohlrabi Planting Timeline — Yavapai County, AZ

Kohlrabi Planting Calendar

Activity When Date Range
Start Indoors March 5 Mar 5 – Mar 19
Transplant Outdoors April 9 Apr 9 – Apr 23
Direct Sow March 26 Mar 26 – Apr 16
Harvest May 28 May 28 – Jul 2
Fall Sowing August 27 Aug 27 – Sep 10

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May Harvest
June Harvest
July Harvest
August Fall Sowing
September Fall Sowing
October
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 8b

📆 Growing Season

210 days in Yavapai County

Growing Tips for Kohlrabi in Yavapai County

Direct sow Kohlrabi outdoors after April 09 in Yavapai County when soil has warmed and frost danger has passed.

Sandy soil in Yavapai 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 101°F in Yavapai County, provide afternoon shade for Kohlrabi and water deeply in the morning.

Your generous 210.0-day season in Yavapai 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 Yavapai County, AZ?

Yavapai County is in Zone 8b with an average last frost of April 9. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Yavapai County, AZ?

Yavapai County, Arizona is in USDA Hardiness Zone 8b. The average last spring frost is April 9 and first fall frost is November 5.

🌱

Your Yavapai County Garden Planner — Free

A 24-page printable planner built for Yavapai County (Zone 8b). 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 Yavapai 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.