What are the best heirloom tomatoes for Michigan?

For Zone 6a Michigan, Cherokee Purple, Brandywine, Black Krim, Mortgage Lifter, and Green Zebra are reliable performers. Early-season heirlooms like Stupice and Black Sea Man are valuable for northern Michigan or gardeners who want their first taste before August. The key in Michigan is selecting varieties with 80 days or fewer to maturity, unless you are willing to start seeds very early indoors.

Do heirloom tomatoes grow well in Michigan?

Yes, with attention to timing and variety selection. Michigan's 148-day growing season in Zone 6a is sufficient for most heirloom varieties, though late-maturing types like Brandywine need to be started indoors by March 1 to hit their peak before fall frost. Disease resistance matters more for heirlooms in Michigan because many lack the disease-resistance genes bred into modern hybrids.

How do you save heirloom tomato seeds?

Select a fully ripe, healthy fruit from your strongest plant. Scoop out the seeds and gel into a small jar with water. Let ferment at room temperature for 2 to 3 days, stirring daily. The viable seeds sink. Pour off the water and floating matter, rinse the sunk seeds, and dry on a plate or paper towel for 1 to 2 weeks. Store in a sealed envelope or jar in a cool, dry location.

Michigan Gardening Guide

Heirloom Tomatoes in Michigan

By Chris Izworski, Freighter View Farms — Bay City, Michigan — Zone 6a — Updated March 2026

There is a gap between the tomato photograph in a seed catalog and the tomato you actually grow in Michigan. The catalog photograph was probably taken in California or the Pacific Northwest. Michigan is not California. We have a shorter season, more humidity, more dramatic temperature swings between day and night, and a late spring that keeps you waiting while the rest of the gardening internet is already celebrating harvests. This guide is about which heirlooms close that gap.

Why Heirlooms in Michigan

The case against heirloom tomatoes in Michigan is real. Most heirlooms lack the disease-resistance genes (V, F, N, T, A) that modern hybrids carry. Michigan summers are humid. Fungal disease, particularly early blight and septoria leaf spot, is a reliable presence in most Zone 6a gardens by August. Heirlooms crack more readily in the wet-dry-wet rain cycles of a Michigan summer. And many of the most celebrated varieties, Brandywine foremost among them, have day-to-maturity counts that push hard against our 148-day growing season.

The case for them is harder to argue in the abstract and easier to make in August. Flavor. Complexity. The deep mineral richness of a Cherokee Purple sliced thickly, the brightness of a Mortgage Lifter, the way a Sungold is somehow better than it has any right to be. And for gardeners who save seeds, heirlooms are the only option: open-pollinated, true-breeding, seeds you can take from this year's best plant and put in the ground next spring.

The answer for Michigan is not a choice between heirlooms and hybrids. It is knowing which heirlooms perform reliably here, giving them the conditions they need, and accepting a few losses along the way.

Variety Guide: What Performs in Zone 6a

Days to maturity is measured from transplant date. All of these varieties have been grown, observed, or researched specifically for Zone 6a Michigan conditions. The field notes marked FVF are from Freighter View Farms in Bay City.

Cherokee Purple

80 daysIndeterminateBeefsteak

Dusty rose-purple with green shoulders. Dense, meaty flesh with rich, complex flavor. One of the most reliable large heirlooms in Michigan. Handles cooler nights better than most dark varieties.

Our most consistent producer. Fruit runs 8 to 14 oz. Stake aggressively. Watch for cracking after heavy rain. Start seeds by March 10 for a strong first harvest before Labor Day.

Brandywine (Pink)

80 to 100 daysIndeterminateBeefsteak

The benchmark heirloom, for better or worse. Enormous potato-leaf plants. Fruit can reach 2 pounds. Flavor is extraordinary when the season cooperates. In Michigan, it cooperates most years if you start early and give it the warmest spot in your yard.

Start seeds March 1. Not March 15. Plant in the south-facing bed. By late August, it makes everything worth it. Loses every year to at least some blight.

Black Krim

75 to 80 daysIndeterminateBeefsteak

Deep mahogany-red with a briny, complex flavor that develops best in heat. Originally from Crimea. Handles cooler nights better than most dark heirlooms, which makes it a good choice for lakeshore Michigan gardens.

Excellent in the Saginaw Bay climate. Cracking is the main issue after rain. Flavor is worth it. Not as productive as Cherokee Purple but arguably better tasting in a great year.

Mortgage Lifter

80 daysIndeterminateBeefsteak

Pink, mild, and massive. Bred by a West Virginia gardener in the 1940s who crossed four large tomatoes over six years until he had something that sold well enough to pay off his mortgage. Excellent flavor, very low acid. Enormous plants.

A crowd-pleaser with low-acid flavor. Good producer for its size. Less drama than Brandywine, nearly as good eating. Reliable in Zone 6a with proper staking.

Green Zebra

75 daysIndeterminateMedium Slicer

Bright lime green with yellow stripes when ripe. Tangy, acidic, zippy flavor. Fruit runs 3 to 4 oz. A visual standout in the garden and on the plate. Good disease tolerance compared to many heirlooms.

Dependable producer. The challenge is knowing when it is ripe: look for yellow stripes brightening and the fruit giving slightly under pressure. Do not wait for it to turn red. It will not.

Stupice

52 to 60 daysIndeterminateSmall Slicer

Czech heirloom bred for cold climates. Potato-leaf foliage, 2 to 3 oz fruits, excellent early production. Not a flavor champion by itself but outstanding for its reliable early harvest in difficult conditions. Essential for northern Michigan or cold springs.

The first ripe tomato in the garden every year, usually by late July. Smaller fruit with good flavor for its size. Plant alongside a late-season variety for continuous harvest.

Aunt Ruby's German Green

80 daysIndeterminateBeefsteak

Large green-when-ripe beefsteak with complex, sweet flavor. The green color tricks inexperienced gardeners into picking it too early. Ripe fruit has a yellow-green blush and gives to pressure. Very low acid, excellent for fresh eating.

Takes patience. Once you learn when it is ripe, it is genuinely wonderful. Michigan humidity does not seem to bother it as much as other large heirlooms.

San Marzano

78 to 80 daysIndeterminatePaste

The benchmark paste tomato. Elongated, meaty, low-moisture, low-seed. The authentic Italian variety is indeterminate and grows tall. Excellent for sauce, canning, and roasting. Flavor intensifies dramatically when cooked.

More susceptible to blight than modern paste varieties. Worth growing for the flavor difference in sauce. Stake to 6 feet and plan for some late-season disease management.

Yellow Pear

78 daysIndeterminateCherry

Small, bright yellow, teardrop-shaped cherry tomatoes with mild, sweet flavor. Extremely productive. A favorite for children's gardens and fresh salads. Very crack-resistant for a cherry type.

Will take over the bed if you let it. Give it a large cage or stake. Production is relentless from mid-August until frost. Good for introducing new gardeners to heirlooms.

Principe Borghese

75 daysDeterminateSmall Paste

Traditional Italian drying tomato. Small, dry, intensely flavored. Originally grown for sun-drying. Determinate habit means a concentrated harvest window, excellent for preserving. Very productive and relatively disease-resistant.

The tomato I grow specifically for drying in the dehydrator. Slice in half, 8 hours at 145 degrees. Stores for a year. Plant more than you think you need.

Michigan's Heirloom Challenges and How to Handle Them

Blight

Early blight (Alternaria) and septoria leaf spot are the two most consistent diseases in Zone 6a. Both are fungal, both spread from splashing soil to leaves, and both gain a foothold in the humid Michigan summers of July and August. Heirlooms have no bred-in resistance.

What you can do: mulch heavily to prevent soil splash, stake or cage to improve airflow, water at the base rather than overhead, and remove affected lower leaves promptly as the season progresses. Copper-based fungicide sprays can slow spread if applied preventively. Accept that some blight is inevitable and plant accordingly.

Cracking

Most heirloom beefsteak types crack after uneven moisture, especially after a soaking rain following a dry period. Michigan delivers this pattern reliably. Mulching to regulate soil moisture helps. Harvesting fruit that has achieved its color but is still slightly firm reduces losses. A tomato you harvest a day early and ripen on the counter is better than one that cracks on the vine overnight.

Season Length

For long-season varieties like Brandywine and some of the large Russian beefsteaks, Michigan's 148-day growing season is sufficient but not generous. Start seeds early (March 1 for the slowest varieties), use the warmest spot in your garden, and consider season extension with black plastic mulch on the soil to add heat units in a cold spring.

The year I grew nine varieties side by side, the Mortgage Lifter outlasted all of them in terms of consistent production through a July that was wetter than most. The Brandywine was better on its best day. The Black Krim was better on my favorite day. But the Mortgage Lifter was there every morning, producing, without drama. There is a case to be made for the reliable tomato even in a garden where you are allowed to love the difficult ones.

Saving Seeds from Heirloom Tomatoes

Seed saving is the reason heirlooms exist. A Brandywine seed you save from this year's plant is genetically connected to the same variety grown by American gardeners for over a century. That is not marketing. It is a form of preservation.

Select the right fruit. Choose from your healthiest, most productive plant. Pick a fruit that represents the variety at its best: proper size, color, shape. Let it ripen fully on the vine, even past the eating stage if needed. The seeds inside an overripe tomato are fully mature.
Scoop seeds and gel into a jar. Cut the tomato equatorially and squeeze the seed chambers into a small glass jar. Add a tablespoon of water. The gel coating on the seeds inhibits germination and carries a natural anti-fungal compound, but it needs to be removed for storage.
Ferment for 2 to 3 days. Cover loosely (not airtight) and leave at room temperature. Stir once a day. A layer of mold will form on top. This is normal and is actually part of the process. The gel breaks down and viable seeds sink to the bottom.
Rinse and separate. Pour off the water, floating debris, and mold carefully. Add clean water and swirl. Viable seeds sink. Pour off floating matter and repeat until the water runs clear and only firm seeds remain at the bottom.
Dry thoroughly. Spread seeds on a ceramic plate or piece of glass (not paper towel, which they stick to). Dry for 10 to 14 days in a warm, well-ventilated location. Seeds should be completely dry and break rather than bend when pressed.
Store properly. Place in a labeled paper envelope or small glass jar with a desiccant packet. Store in a cool, dark, dry location. A refrigerator works well. Properly stored heirloom tomato seeds remain viable for 4 to 6 years, often longer.

More detail on the full seed saving process, including isolation distances to maintain variety purity, is at the Heirloom Seed Saving Guide.

Growing Heirlooms in Michigan: Fundamentals

Factor	What to Do in Zone 6a
Seed starting	6 to 8 weeks before transplant date. March 1 for long-season varieties. March 10 to 15 for most others.
Transplant timing	May 20 to June 1. Soil must reach 60°F at 4-inch depth. Do not rush this.
Spacing	24 to 36 inches between indeterminate plants. 18 to 24 inches for determinate. Heirlooms need airflow.
Staking and caging	Plan for 5 to 6 feet on indeterminate heirlooms. A wire cage that works for Celebrity will not contain a Brandywine.
Mulching	3 to 4 inches of straw or wood chip mulch around the base. Reduces soil splash, moderates moisture, keeps roots cool in August heat.
Watering	Consistent moisture is more important than volume. Irregular watering causes blossom end rot and cracking. 1 to 1.5 inches per week including rain.
Fertilizing	Balanced fertilizer at transplant, then switch to low-nitrogen, higher phosphorus and potassium as fruit sets. Excess nitrogen = beautiful plants, poor fruit.
Disease management	Mulch, stake, remove affected lower leaves, apply copper fungicide preventively starting in July. Accept some blight as inevitable.
Harvest window	Most heirlooms ripen July 25 through September 30 in Bay City. The last days before first frost are often productive if plants are still healthy.

Sources: Freighter View Farms field observations, Bay City MI (2019 to 2025); Michigan State University Extension Vegetable Planting Guide; Baker Creek Heirloom Seeds variety descriptions; Seed Savers Exchange. Planting calendar context at Zone 6a Planting Calendar.

When to Plant Tomatoes in Michigan Zone 6a Planting Calendar Heirloom Seed Saving Heirloom vs Hybrid Seeds Companion Planting Zone 6a Michigan Frost Dates