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When to Plant Tomatillo in Floyd County, IA

Floyd County, Iowa Zone 5a May

This month in Floyd County, Iowa

Each item below is timed to Floyd County, Iowa's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 1
Avg. first frost October 7
Soil temp (4") 53°F
Watering Moderate
Pest pressure Low
Daylight 14.5 hrs
  1. Set out tomatillo seedlings

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

  2. Outdoor sowing time: tomatillo

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

Get ahead of June
  • Starting indoors: 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.

Floyd County, Iowa is in USDA Zone 5a. The average last spring frost is May 1 and the first fall frost is October 7, giving you a growing season of approximately 159 days.

At an elevation of 714 feet, Floyd County receives approximately 32.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Tomatillo to ensure they mature before fall.

Floyd County, IA (Zone 5a) Moderate season
159 days
Last Spring Frost May 1
159 growing days
First Fall Frost October 7
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Floyd County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (13 days to spare)
Start indoors: Feb 28 Transplant: May 9 🍅 Harvest: Jul 11 – Sep 19
Recommended (50%) ✓ Fits season (12 days to spare)
Start indoors: Mar 6 Transplant: May 15 🍅 Harvest: Jul 17 – Sep 25
Safe Start (90%) ✓ Fits season (7 days to spare)
Start indoors: Mar 20 Transplant: May 29 🍅 Harvest: Jul 31 – Oct 9

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 Floyd County

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

Soil pH

Your soil pH (5.9–6.8) overlaps with Tomatillo's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (4.0%). Annual compost additions will help Tomatillo.

How to Plant Tomatillo

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

Succession Planting Tomatillo

3
successive plantings in your 159-day season

Sow every 6.9 weeks. Last sowing by Jul 14 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.9″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 331 gal / 100 sq ft

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 1.4" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 3.1" 0" ❄️ Dormant
May 4.8" 3.6" 1.2" 💧 Light watering
Jun 4.8" 3.8" 1" 💧 Light watering
Jul 4.8" 3.9" 0.9" 💧 Light watering
Aug 4.8" 3.4" 1.4" 💧 Light watering
Sep 4.8" 3" 1.8" 💧 Light watering
Oct 4.8" 2.9" 1.9" 💧 Light watering
Nov 2.1" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Floyd 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 ~725 GDD — county provides 1,590 GDD Excellent fit

Tomatillo Planting Timeline — Floyd County, IA

Tomatillo Planting Calendar

Activity When Date Range
Start Indoors March 6 Mar 6 – Mar 20
Transplant Outdoors May 15 May 15 – May 29
Direct Sow May 8 May 8 – May 29
Harvest July 17 Jul 17 – Sep 25

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · Only during dry spells

📅 Days to Maturity

60–85 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

159 days in Floyd County

Growing Tips for Tomatillo in Floyd County

Direct sow Tomatillo outdoors after May 01 in Floyd 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.

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 Floyd County, IA?

Floyd County is in Zone 5a with an average last frost of May 1. Plan your Tomatillo planting based on this frost date — see the calendar above for exact timing.

What planting zone is Floyd County, IA?

Floyd County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is May 1 and first fall frost is October 7.

🌱

Your Floyd County Garden Planner — Free

A 24-page printable planner built for Floyd County (Zone 5a). 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 Floyd County, IA. 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.