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When to Plant Tomatoes in Alcona County, MI

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.

Alcona County, Michigan is in USDA Zone 5a. The average last spring frost is May 17 and the first fall frost is October 3, giving you a growing season of approximately 139 days.

At an elevation of 1,061 feet, Alcona County receives approximately 39 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Tomatoes during the growing season.

Alcona County, MI (Zone 5a) Short season
139 days
Last Spring Frost May 17
139 growing days
First Fall Frost October 3

Alcona County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 15 Transplant: May 24 🍅 Harvest: Jul 26 – Oct 4
Recommended (50%) ✗ May not fit
Start indoors: Mar 22 Transplant: May 31 🍅 Harvest: Aug 2 – Oct 11
Safe Start (90%) ✗ May not fit
Start indoors: Apr 2 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 Alcona County

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

Soil pH

Your soil pH (6.1โ€“7.2) overlaps with Tomatoes's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Alcona County is excellent for Tomatoes โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.4%) โ€” 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 139-day season

Sow every 6.9 weeks. Last sowing by Jul 10 to harvest before frost.

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
1.2″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 32 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 1.7" 0" โ„๏ธ Dormant
Feb โ€” 1.6" 0" โ„๏ธ Dormant
Mar โ€” 3" 0" โ„๏ธ Dormant
Apr โ€” 4" 0" โ„๏ธ Dormant
May 5.2" 4" 1.2" ๐Ÿ’ง Light watering
Jun 5.2" 4.4" 0.8" ๐Ÿ’ง Light watering
Jul 5.2" 4.8" 0.4" ๐Ÿ’ง Light watering
Aug 5.2" 4.4" 0.8" ๐Ÿ’ง Light watering
Sep 5.2" 3.8" 1.4" ๐Ÿ’ง Light watering
Oct 5.2" 2.8" 2.4" ๐Ÿ’ง Light watering
Nov โ€” 2.8" 0" โ„๏ธ Dormant
Dec โ€” 1.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Alcona County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,051 GDD — county provides 2,015 GDD Excellent fit

Tomatoes Planting Timeline โ€” Alcona County, MI

Tomatoes Planting Calendar

Activity When Date Range
Start Indoors March 22 Mar 22 โ€“ Apr 5
Transplant Outdoors May 31 May 31 โ€“ Jun 14
Direct Sow May 24 May 24 โ€“ Jun 14
Harvest August 2 Aug 2 โ€“ Oct 11

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.2"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

60โ€“85 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

139 days in Alcona County

Growing Tips for Tomatoes in Alcona County

Direct sow Tomatoes outdoors after May 17 in Alcona 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 Alcona 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 →

๐ŸŒพ 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 35ยฐF, 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 Alcona County, MI?

Alcona County is in Zone 5a with an average last frost of May 17. Plan your Tomatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Alcona County, MI?

Alcona County, Michigan is in USDA Hardiness Zone 5a. The average last spring frost is May 17 and first fall frost is October 3.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Alcona County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Alcona County, MI. Local conditions may vary. Last updated: April 2026.