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When to Plant Kale in Mohave County, AZ

Mohave County, Arizona Zone 9b May

May in the garden — Mohave County, Arizona

Welcome to May in Zone 9b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 5
Avg. first frost November 8
Soil temp (4") 64°F
Watering Critical
Pest pressure High
Daylight 13.9 hrs
  1. Indoor seed-starting week for kale

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

  2. Start harvesting kale

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

To set up a strong June, finish these tasks
  • First harvests: kale

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Kale is an exceptionally hardy, nutrient-dense green available in curly, lacinato, and Russian varieties. It tolerates heavy frost and often tastes sweeter after cold exposure.

Mohave County, Arizona is in USDA Zone 9b. The average last spring frost is April 5 and the first fall frost is November 8, giving you a growing season of approximately 217 days.

At an elevation of 3,748 feet, Mohave County receives approximately 8.2 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Kale may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Kale will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Kale successfully. Mulch heavily to conserve soil moisture.

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

Mohave County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (114 days to spare)
Start indoors: Feb 23 Transplant: Mar 23 🍅 Harvest: May 18 – Jul 13
Recommended (50%) ✓ Fits season (105 days to spare)
Start indoors: Mar 8 Transplant: Apr 5 🍅 Harvest: May 31 – Jul 26
Safe Start (90%) ✓ Fits season (106 days to spare)
Start indoors: Mar 20 Transplant: Apr 17 🍅 Harvest: Jun 12 – Aug 7

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 Mohave County

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

Soil pH

Your soil pH (7.2–8.4) is more alkaline than Kale prefers (6.0–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Kale.

Organic Matter

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

How to Plant Kale

1"
Planting Depth
15"
Between Plants
24"
Between Rows

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

Succession Planting Kale

5
successive plantings in your 217-day season

Sow every 5.7 weeks. Last sowing by Aug 30 to harvest before frost.

For a dedicated fall crop, sow by Sep 13.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.2″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 2,042 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Kale

Kale needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Kale Needs Rainfall You Supplement Action
Jan 0.6" 0" ❄️ Dormant
Feb 0.4" 0" ❄️ Dormant
Mar 0.4" 0" ❄️ Dormant
Apr 3.5" 0.3" 3.2" 🚿 Regular watering
May 3.5" 0.2" 3.3" 🚿 Regular watering
Jun 3.5" 0.3" 3.2" 🚿 Regular watering
Jul 3.5" 1.5" 2" 🚿 Regular watering
Aug 3.5" 1.6" 1.9" 🚿 Regular watering
Sep 3.5" 1" 2.5" 🚿 Regular watering
Oct 3.5" 0.8" 2.7" 🚿 Regular watering
Nov 3.5" 0.4" 3.1" 🚿 Regular watering
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Mohave County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Kale 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.

Kale needs ~1,320 GDD — county provides 4,774 GDD Excellent fit

Kale Planting Timeline — Mohave County, AZ

Kale Planting Calendar

Activity When Date Range
Start Indoors March 8 Mar 8 – Mar 22
Transplant Outdoors April 5 Apr 5 – Apr 19
Direct Sow March 15 Mar 15 – Apr 5
Harvest May 31 May 31 – Jul 26
Fall Sowing September 13 Sep 13 – Sep 27

Plant 1" deep · 15" apart · Rows 24" 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
September Fall Sowing
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · 2-3 times/week

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9b

📆 Growing Season

217 days in Mohave County

Growing Tips for Kale in Mohave County

Direct sow Kale outdoors after April 05 in Mohave County when soil has warmed and frost danger has passed.

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

Summer highs in Mohave County reach 96°F — grow Kale as a spring or fall crop. Use shade cloth if planting in summer.

Common pests for Kale 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 or transplant in early spring or late summer. Harvest outer leaves first to keep plants productive. Kale overwinters in many climates and can provide greens all year.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Kale Seeds
Life Cycle Biennial
Pollination Cross-Pollinated (insects)
How to Collect Allow 2nd year flower stalks to dry. Harvest pods when tan.
Storage Store airtight; viable 5 years at 35°F, under 50% humidity.

Isolate 1/2 mile from other brassicas (broccoli, cabbage, etc.) — they all cross.

Frequently Asked Questions

When should I plant Kale in Mohave County, AZ?

Mohave County is in Zone 9b with an average last frost of April 5. Plan your Kale planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mohave County, AZ?

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

🌱

Your Mohave County Garden Planner — Free

A 24-page printable planner built for Mohave 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.

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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 Mohave 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.