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When to Plant Tomatoes in Mohave County, AZ

Tomatoes are the most popular home garden crop, available in thousands of varieties from tiny cherries to massive beefsteaks. They are warm-season plants needing full sun.

Mohave County, Arizona is in USDA Zone 8b. 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 96ยฐF, so Tomatoes may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Tomatoes will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Tomatoes successfully. Mulch heavily to conserve soil moisture.

Mohave County, AZ (Zone 8b) 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 (79 days to spare)
Start indoors: Feb 2 Transplant: Apr 6 🍅 Harvest: Jun 8 – Aug 17
Recommended (50%) ✓ Fits season (70 days to spare)
Start indoors: Feb 15 Transplant: Apr 19 🍅 Harvest: Jun 21 – Aug 30
Safe Start (90%) ✓ Fits season (71 days to spare)
Start indoors: Feb 27 Transplant: May 1 🍅 Harvest: Jul 3 – Sep 11

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 Tomatoes's growing requirements.

Soil pH

Your soil pH (7.2โ€“8.4) is more alkaline than Tomatoes prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Tomatoes.

Organic Matter

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

How to Plant Tomatoes

0.5"
Planting Depth
24"
Between Plants
36"
Between Rows

Succession Planting Tomatoes

4
successive plantings in your 217-day season

Sow every 6.9 weeks. Last sowing by Aug 15 to harvest before frost.

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
0.2″/week
You supply
1.7″/week
Watering frequency 2-3 times/week
Season total 3,248 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Tomatoes

Tomatoes needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.

Month Tomatoes Needs Rainfall You Supplement Action
Jan โ€” 0.6" 0" โ„๏ธ Dormant
Feb โ€” 0.4" 0" โ„๏ธ Dormant
Mar โ€” 0.4" 0" โ„๏ธ Dormant
Apr 5.2" 0.3" 4.9" ๐Ÿšฟ Regular watering
May 5.2" 0.2" 5" ๐Ÿšฟ Regular watering
Jun 5.2" 0.3" 4.9" ๐Ÿšฟ Regular watering
Jul 5.2" 1.5" 3.7" ๐Ÿšฟ Regular watering
Aug 5.2" 1.6" 3.6" ๐Ÿšฟ Regular watering
Sep 5.2" 1" 4.2" ๐Ÿšฟ Regular watering
Oct 5.2" 0.8" 4.4" ๐Ÿšฟ Regular watering
Nov 5.2" 0.4" 4.8" ๐Ÿšฟ Regular watering
Dec โ€” 0.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Nov in Mohave County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Tomatoes 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" โ€” every day above 50ยฐF 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.

Tomatoes needs ~1,595 GDD — county provides 4,774 GDD Excellent fit

Tomatoes Planting Timeline โ€” Mohave County, AZ

Tomatoes Planting Calendar

Activity When Date Range
Start Indoors February 15 Feb 15 โ€“ Mar 1
Transplant Outdoors April 19 Apr 19 โ€“ May 3
Direct Sow April 12 Apr 12 โ€“ May 3
Harvest June 21 Jun 21 โ€“ Aug 30

Plant 0.5" deep ยท 24" apart ยท Rows 36" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Harvest
August Harvest
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.2"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

60โ€“85 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 8b

๐Ÿ“† Growing Season

217 days in Mohave County

Growing Tips for Tomatoes in Mohave County

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

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

With summer highs reaching 96ยฐF in Mohave County, provide afternoon shade for Tomatoes and water deeply in the morning.

Common pests for Tomatoes in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.

Mohave County receives only 8" of rain annually. Tomatoes needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 6-8 weeks before last frost. Bury transplants deep to encourage rooting along the stem. Provide consistent moisture to prevent blossom end rot and cracking.

Recommended Tomatoes Varieties for Mohave County

Heat-set varieties that pollinate reliably above 90ยฐF

Solar Fire Florida 91 Phoenix Heat Wave II

Companion Planting

Good Companions

Avoid Planting Near

  • Cabbage
  • Fennel
  • Potatoes

Check more plant combinations with our Companion Planting Checker →

๐ŸŒพ Save Your Own Tomatoes Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Scoop seeds from ripe fruit; ferment 2-3 days to remove gel coating.
Storage Store airtight; viable 4-6 years at 35ยฐF, under 45% humidity.

Isolate 25 ft between varieties for purity. Use open-pollinated varieties for true-to-type seeds.

Frequently Asked Questions

When should I plant Tomatoes in Mohave County, AZ?

Mohave County is in Zone 8b with an average last frost of April 5. Plan your Tomatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Mohave County, AZ?

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

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Mohave County gardeners in Zone 8b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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: April 2026.