Blog

When to Plant Tomatillo in McLean County, ND

McLean County, North Dakota Zone 4a May

May in McLean County, North Dakota — your action list

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in McLean County, North Dakota.

Avg. last frost May 12
Avg. first frost September 30
Soil temp (4") 54°F
Watering High
Pest pressure Low
Daylight 14.9 hrs
  1. Sow tomatillo where they'll grow

    Your soil is 54°F — warm enough for these to germinate without babying.

June prep starts now
  • Transplants going out: tomatillo

Instant PDF download. No spam, unsubscribe any time.

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

McLean County, North Dakota is in USDA Zone 4a. The average last spring frost is May 12 and the first fall frost is September 30, giving you a growing season of approximately 141 days.

At an elevation of 1,071 feet, McLean County receives approximately 21.5 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Tomatillo to ensure they mature before fall.

McLean County, ND (Zone 4a) Short season
141 days
Last Spring Frost May 12
141 growing days
First Fall Frost September 30
Share this guide:

McLean County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 2 Transplant: May 25 🍅 Harvest: Jul 27 – Oct 5
Recommended (50%) ✗ May not fit
Start indoors: Mar 10 Transplant: Jun 2 🍅 Harvest: Aug 4 – Oct 13
Safe Start (90%) ✗ May not fit
Start indoors: Mar 19 Transplant: Jun 11 🍅 Harvest: Aug 13 – Oct 22

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 McLean County

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

Soil pH

Your soil pH (6.6–7.8) is more alkaline than Tomatillo prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.5%). Annual compost additions will help Tomatillo.

How to Plant Tomatillo

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

Succession Planting Tomatillo

2
successive plantings in your 141-day season

Sow every 6.9 weeks. Last sowing by Jul 07 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.6″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 692 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.5" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 4.8" 2.5" 2.3" 💧 Light watering
Jun 4.8" 1.5" 3.3" 🚿 Regular watering
Jul 4.8" 1.9" 2.9" 🚿 Regular watering
Aug 4.8" 2.4" 2.4" 🚿 Regular watering
Sep 4.8" 1.8" 3" 🚿 Regular watering
Oct 1.9" 0" ❄️ Dormant
Nov 1.3" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in McLean 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 ~834 GDD — county provides 1,621 GDD Excellent fit

Tomatillo Planting Timeline — McLean County, ND

Tomatillo Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 – Mar 24
Transplant Outdoors June 2 Jun 2 – Jun 16
Direct Sow May 26 May 26 – Jun 16
Harvest August 4 Aug 4 – Oct 13

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
Share this guide:

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · 1-2 times/week

📅 Days to Maturity

60–85 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 4a

📆 Growing Season

141 days in McLean County

Growing Tips for Tomatillo in McLean County

Direct sow Tomatillo outdoors after May 12 in McLean 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.

McLean 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 McLean County, ND?

McLean County is in Zone 4a with an average last frost of May 12. Plan your Tomatillo planting based on this frost date — see the calendar above for exact timing.

What planting zone is McLean County, ND?

McLean County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 12 and first fall frost is September 30.

🌱

Your McLean County Garden Planner — Free

A 24-page printable planner built for McLean County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for McLean County, ND. 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.