Blog

When to Plant Tomatoes in Pierce County, ND

Pierce County, North Dakota Zone 3b May

Pierce County, North Dakota gardeners: here's your May plan

A quick May briefing for Pierce County, North Dakota gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 17
Avg. first frost September 22
Soil temp (4") 49°F
Watering Moderate
Pest pressure Low
Daylight 15 hrs
  1. Plant tomatoes from seed, right in the garden

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

To set up a strong June, finish these tasks
  • Transplants going out: tomatoes

Instant PDF download. No spam, unsubscribe any time.

Tomatoes are the most popular home garden crop, available in thousands of varieties from tiny cherries to massive beefsteaks. They are warm-season plants needing full sun.

Pierce County, North Dakota is in USDA Zone 3b. The average last spring frost is May 17 and the first fall frost is September 22, giving you a growing season of approximately 128 days.

At an elevation of 874 feet, Pierce County receives approximately 28.5 inches of rainfall annually with predominantly loam soil. Summer highs average 78°F, so choose short-season varieties of Tomatoes to ensure they mature before fall.

Pierce County, ND (Zone 3b) Short season
128 days
Last Spring Frost May 17
128 growing days
First Fall Frost September 22

Pierce County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 9 Transplant: Jun 1 🍅 Harvest: Aug 3 – Oct 5
Recommended (50%) ✗ May not fit
Start indoors: Mar 15 Transplant: Jun 7 🍅 Harvest: Aug 9 – Oct 11
Safe Start (90%) ✗ May not fit
Start indoors: Mar 26 Transplant: Jun 18 🍅 Harvest: Aug 20 – 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 Pierce County

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

Soil pH

Your soil pH (6.7–7.8) is more alkaline than Tomatoes prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.0%) — Tomatoes will thrive.

How to Plant Tomatoes

0.5"
Planting Depth
24"
Between Plants
36"
Between Rows

Succession Planting Tomatoes

2
successive plantings in your 128-day season

Sow every 6.9 weeks. Last sowing by Jun 29 to harvest before frost.

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
0.9″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 362 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Tomatoes

Tomatoes needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.

Month Tomatoes Needs Rainfall You Supplement Action
Jan 0.8" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 3.2" 0" ❄️ Dormant
May 5.2" 3.7" 1.5" 💧 Light watering
Jun 5.2" 4.7" 0.5" 💧 Light watering
Jul 5.2" 4" 1.2" 💧 Light watering
Aug 5.2" 3.1" 2.1" 💧 Light watering
Sep 5.2" 2.9" 2.3" 💧 Light watering
Oct 1.6" 0" ❄️ Dormant
Nov 0.8" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

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

Tomatoes 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.

Tomatoes needs ~616 GDD — county provides 1,088 GDD Excellent fit

Tomatoes Planting Timeline — Pierce County, ND

Tomatoes Planting Calendar

Activity When Date Range
Start Indoors March 15 Mar 15 – Mar 29
Transplant Outdoors June 7 Jun 7 – Jun 21
Direct Sow May 31 May 31 – Jun 21
Harvest August 9 Aug 9 – Oct 11

Plant 0.5" deep · 24" apart · Rows 36" 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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.2"/week · 1-2 times/week

📅 Days to Maturity

60–85 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 3b

📆 Growing Season

128 days in Pierce County

Growing Tips for Tomatoes in Pierce County

Direct sow Tomatoes outdoors after May 17 in Pierce County when soil has warmed and frost danger has passed.

Common pests for Tomatoes 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. Bury transplants deep to encourage rooting along the stem. Provide consistent moisture to prevent blossom end rot and cracking.

Recommended Tomatoes Varieties for Pierce County

Choose determinate, early-maturing varieties for your short season

Early Girl (52d) Stupice (55d) Glacier (55d) Sub Arctic Plenty (45d)

Companion Planting

Good Companions

Avoid Planting Near

  • Cabbage
  • Fennel
  • Potatoes

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Tomatoes Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Scoop seeds from ripe fruit; ferment 2-3 days to remove gel coating.
Storage Store airtight; viable 4-6 years at 35°F, under 45% humidity.

Isolate 25 ft between varieties for purity. Use open-pollinated varieties for true-to-type seeds.

Frequently Asked Questions

When should I plant Tomatoes in Pierce County, ND?

Pierce County is in Zone 3b with an average last frost of May 17. Plan your Tomatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Pierce County, ND?

Pierce County, North Dakota is in USDA Hardiness Zone 3b. The average last spring frost is May 17 and first fall frost is September 22.

🌱

Your Pierce County Garden Planner — Free

A 24-page printable planner built for Pierce County (Zone 3b). 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 Pierce 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.