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When to Plant Tomatillo in La Paz County, AZ

La Paz County, Arizona Zone 9b April

April in the garden — La Paz County, Arizona

Here's what deserves your attention in La Paz County, Arizona this month. Everything below is tailored to Zone 9b and timed around your local frost dates.

Avg. last frost February 2
Avg. first frost December 6
Soil temp (4") 55°F
Watering Critical
Pest pressure High
Daylight 12.8 hrs
  1. It's harvest week for tomatillo

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

May will be here before you know it — start on
  • First harvests: tomatillo

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Tomatillos are a Mexican staple that produces tart, green fruits enclosed in papery husks. They are essential for salsa verde and green sauces.

La Paz County, Arizona is in USDA Zone 9b. The average last spring frost is February 2 and the first fall frost is December 6, giving you a growing season of approximately 307 days.

At an elevation of 4,875 feet, La Paz County receives approximately 17.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 105°F, so Tomatillo may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Tomatillo will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Tomatillo successfully. Mulch heavily to conserve soil moisture.

La Paz County, AZ (Zone 9b) Year-round
307 days
Last Spring Frost February 2
307 growing days
First Fall Frost December 6

La Paz County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (179 days to spare)
Start indoors: Dec 7 Transplant: Jan 25 🍅 Harvest: Mar 29 – Jun 7
Recommended (50%) ✓ Fits season (167 days to spare)
Start indoors: Dec 22 Transplant: Feb 9 🍅 Harvest: Apr 13 – Jun 22
Safe Start (90%) ✓ Fits season (163 days to spare)
Start indoors: Jan 16 Transplant: Mar 6 🍅 Harvest: May 8 – Jul 17

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 La Paz County

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

Soil pH

Your soil pH (7.2–8.3) is more alkaline than Tomatillo prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is low (0.7%). Add 2-3 inches of compost before planting Tomatillo.

How to Plant Tomatillo

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

Succession Planting Tomatillo

6
successive plantings in your 307-day season

Sow every 6.9 weeks. Last sowing by Sep 12 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.2″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 2,838 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Tomatillo

Tomatillo needs approximately 1.1 inches of water per week (4.8" per month). Here's how your county's rainfall compares month by month.

Month Tomatillo Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 4.8" 0.9" 3.9" 🚿 Regular watering
Mar 4.8" 1" 3.8" 🚿 Regular watering
Apr 4.8" 0.6" 4.2" 🚿 Regular watering
May 4.8" 0.4" 4.4" 🚿 Regular watering
Jun 4.8" 0.7" 4.1" 🚿 Regular watering
Jul 4.8" 2.5" 2.3" 💧 Light watering
Aug 4.8" 3.7" 1.1" 💧 Light watering
Sep 4.8" 2.5" 2.3" 💧 Light watering
Oct 4.8" 1.6" 3.2" 🚿 Regular watering
Nov 4.8" 1" 3.8" 🚿 Regular watering
Dec 4.8" 1.2" 3.6" 🚿 Regular watering

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

Tomatillo 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.

Tomatillo needs ~2,084 GDD — county provides 8,855 GDD Excellent fit

Tomatillo Planting Timeline — La Paz County, AZ

Tomatillo Planting Calendar

Activity When Date Range
Start Indoors December 22 Dec 22 – Jan 5
Transplant Outdoors February 9 Feb 9 – Feb 23
Direct Sow February 2 Feb 2 – Feb 23
Harvest April 13 Apr 13 – Jun 22

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · 2-3 times/week

📅 Days to Maturity

60–85 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9b

📆 Growing Season

307 days in La Paz County

Growing Tips for Tomatillo in La Paz County

Direct sow Tomatillo outdoors after February 02 in La Paz County when soil has warmed and frost danger has passed.

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

With summer highs reaching 105°F in La Paz County, provide afternoon shade for Tomatillo and water deeply in the morning.

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

La Paz County receives only 17" of rain annually. Tomatillo needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 6-8 weeks before last frost. Plant at least two plants for cross-pollination. Harvest when fruits fill the husk and it begins to split.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel
  • Dill

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Tomatillo in La Paz County, AZ?

La Paz County is in Zone 9b with an average last frost of February 2. Plan your Tomatillo planting based on this frost date — see the calendar above for exact timing.

What planting zone is La Paz County, AZ?

La Paz County, Arizona is in USDA Hardiness Zone 9b. The average last spring frost is February 2 and first fall frost is December 6.

🌱

Your La Paz County Garden Planner — Free

A 24-page printable planner built for La Paz 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 La Paz County, AZ. Local conditions may vary. Last updated: April 2026.

Sources & credits

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