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When to Plant Tomatillo in Santa Barbara County, CA

Santa Barbara County, California Zone 10a May

May in Santa Barbara County, California — your action list

May is a pivotal month for Santa Barbara County, California gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost February 28
Avg. first frost November 24
Soil temp (4") 73°F
Watering Critical
Pest pressure High
Daylight 13.8 hrs
  1. Harvest tomatillo as they ripen

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

Coming up in June — start thinking about
  • 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.

Santa Barbara County, California is in USDA Zone 10a. The average last spring frost is February 28 and the first fall frost is November 24, giving you a growing season of approximately 269 days.

At an elevation of 2,364 feet, Santa Barbara County receives approximately 19.9 inches of rainfall annually with predominantly loam soil. Summer highs average 89°F, providing good warmth for Tomatillo during the growing season. With low rainfall, drip irrigation is essential for growing Tomatillo successfully. Mulch heavily to conserve soil moisture.

Santa Barbara County, CA (Zone 10a) Long season
269 days
Last Spring Frost February 28
269 growing days
First Fall Frost November 24
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Santa Barbara County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (133 days to spare)
Start indoors: Jan 1 Transplant: Feb 19 🍅 Harvest: Apr 23 – Jul 2
Recommended (50%) ✓ Fits season (129 days to spare)
Start indoors: Jan 17 Transplant: Mar 7 🍅 Harvest: May 9 – Jul 18
Safe Start (90%) ✓ Fits season (117 days to spare)
Start indoors: Feb 24 Transplant: Apr 14 🍅 Harvest: Jun 16 – Aug 25

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 Santa Barbara County

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

Soil pH

Your soil pH (6.5–7.2) overlaps with Tomatillo's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in Santa Barbara County is excellent for Tomatillo — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Tomatillo.

How to Plant Tomatillo

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

Succession Planting Tomatillo

5
successive plantings in your 269-day season

Sow every 6.9 weeks. Last sowing by Aug 31 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.3″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 2,279 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 4" 0" ❄️ Dormant
Feb 4.8" 4.6" 0.2" 💧 Light watering
Mar 4.8" 2.9" 1.9" 💧 Light watering
Apr 4.8" 1.8" 3" 🚿 Regular watering
May 4.8" 0.5" 4.3" 🚿 Regular watering
Jun 4.8" 0.1" 4.7" 🚿 Regular watering
Jul 4.8" 0" 4.8" 🚿 Regular watering
Aug 4.8" 0" 4.8" 🚿 Regular watering
Sep 4.8" 0.2" 4.6" 🚿 Regular watering
Oct 4.8" 0.8" 4" 🚿 Regular watering
Nov 4.8" 2.1" 2.7" 🚿 Regular watering
Dec 2.9" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Santa Barbara 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 ~1,214 GDD — county provides 4,522 GDD Excellent fit

Tomatillo Planting Timeline — Santa Barbara County, CA

Tomatillo Planting Calendar

Activity When Date Range
Start Indoors January 17 Jan 17 – Jan 31
Transplant Outdoors March 7 Mar 7 – Mar 21
Direct Sow February 28 Feb 28 – Mar 21
Harvest May 9 May 9 – Jul 18

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 10a

📆 Growing Season

269 days in Santa Barbara County

Growing Tips for Tomatillo in Santa Barbara County

Direct sow Tomatillo outdoors after February 28 in Santa Barbara County when soil has warmed and frost danger has passed.

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

Santa Barbara County receives only 20" 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 Santa Barbara County, CA?

Santa Barbara County is in Zone 10a with an average last frost of February 28. Plan your Tomatillo planting based on this frost date — see the calendar above for exact timing.

What planting zone is Santa Barbara County, CA?

Santa Barbara County, California is in USDA Hardiness Zone 10a. The average last spring frost is February 28 and first fall frost is November 24.

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Your Santa Barbara County Garden Planner — Free

A 24-page printable planner built for Santa Barbara 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 Santa Barbara County, CA. 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.