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When to Plant Tomatillo in Haakon County, SD

Haakon County, South Dakota Zone 4b May

Your May gardening checklist

Here's what deserves your attention in Haakon County, South Dakota this month. Everything below is tailored to Zone 4b and timed around your local frost dates.

Avg. last frost May 14
Avg. first frost September 28
Soil temp (4") 54°F
Watering High
Pest pressure Low
Daylight 14.6 hrs
  1. Plant tomatillo from seed, right in the garden

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

Looking ahead to June
  • Transplants going out: 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.

Haakon County, South Dakota is in USDA Zone 4b. The average last spring frost is May 14 and the first fall frost is September 28, giving you a growing season of approximately 137 days.

At an elevation of 1,097 feet, Haakon County receives approximately 22.5 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Tomatillo to ensure they mature before fall.

Haakon County, SD (Zone 4b) Short season
137 days
Last Spring Frost May 14
137 growing days
First Fall Frost September 28
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Haakon County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 7 Transplant: May 30 🍅 Harvest: Aug 1 – Oct 10
Recommended (50%) ✗ May not fit
Start indoors: Mar 12 Transplant: Jun 4 🍅 Harvest: Aug 6 – Oct 15
Safe Start (90%) ✗ May not fit
Start indoors: Mar 24 Transplant: Jun 16 🍅 Harvest: Aug 18 – Oct 27

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 Haakon County

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

Soil pH

Your soil pH (6.5–7.5) overlaps with Tomatillo's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Tomatillo.

Organic Matter

Organic matter is excellent (4.1%) — Tomatillo will thrive.

How to Plant Tomatillo

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

Succession Planting Tomatillo

2
successive plantings in your 137-day season

Sow every 6.9 weeks. Last sowing by Jul 05 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.7″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 1,083 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 1.6" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 2" 0" ❄️ Dormant
May 4.8" 2.6" 2.2" 💧 Light watering
Jun 4.8" 1.6" 3.2" 🚿 Regular watering
Jul 4.8" 1.9" 2.9" 🚿 Regular watering
Aug 4.8" 2.3" 2.5" 🚿 Regular watering
Sep 4.8" 2" 2.8" 🚿 Regular watering
Oct 1.7" 0" ❄️ Dormant
Nov 1.8" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Haakon 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 ~779 GDD — county provides 1,472 GDD Excellent fit

Tomatillo Planting Timeline — Haakon County, SD

Tomatillo Planting Calendar

Activity When Date Range
Start Indoors March 12 Mar 12 – Mar 26
Transplant Outdoors June 4 Jun 4 – Jun 18
Direct Sow May 28 May 28 – Jun 18
Harvest August 6 Aug 6 – Oct 15

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May Direct Sow
June Transplant Outdoors Direct Sow
July
August Harvest
September Harvest
October Harvest
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 4b

📆 Growing Season

137 days in Haakon County

Growing Tips for Tomatillo in Haakon County

Direct sow Tomatillo outdoors after May 14 in Haakon 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.

Haakon County receives only 22" 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 Haakon County, SD?

Haakon County is in Zone 4b with an average last frost of May 14. Plan your Tomatillo planting based on this frost date — see the calendar above for exact timing.

What planting zone is Haakon County, SD?

Haakon County, South Dakota is in USDA Hardiness Zone 4b. The average last spring frost is May 14 and first fall frost is September 28.

🌱

Your Haakon County Garden Planner — Free

A 24-page printable planner built for Haakon County (Zone 4b). 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 Haakon County, SD. 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.