Collards in Michigan give you a tough, leafy crop that keeps producing through cool weather and tastes best after a light frost. In Michigan, the key is to use the state’s short growing season and cold nights to your advantage while protecting young plants from spring and fall freezes.
At a glance
- Michigan USDA zones: Mostly zones 4, 5, and 6, with colder inland and U.P. areas in zone 4 and warmer southern lakeshore pockets in zone 6
- Cold tolerance: Collards handle cool weather and light frost; mature plants survive early fall cold better than seedlings
- Best planting window: May through June in most of Michigan; late April to May in zone 6 southern Michigan
- Days to maturity: 50 to 85 days, which fits Michigan’s frost-free window if you start early and keep planting through midsummer
- Sun and water: Full sun with 1 to 1.5 inches of water per week and steady moisture for tender leaves
- Main caveat: Spring frosts, flea beetles, and hard winter freezes end the crop fast unless you use row cover or harvest before deep cold
Why it works in Michigan
Michigan sits mostly in USDA zones 4, 5, and 6, which means collards get a long cool stretch in spring and again in fall. That cool weather is exactly what collards like: they grow briskly below summer heat and stay sweeter after temperatures dip. In zone 4 parts of the Upper Peninsula and northern Lower Peninsula, the frost-free season is short, so you need fast transplanting and aggressive season extension. In zone 5 and zone 6 southern Michigan, collards are easier because you get a longer runway from last frost to first hard freeze. Collards are not a winter-hardy perennial in Michigan soil, so you treat them as a fast annual crop and protect them when frost arrives.
When to plant
In most of Michigan, transplant collards from late April through June, after the soil has warmed and the worst spring freezes have passed. In zone 6 southern Michigan, you can set out transplants in late April or early May; in zone 5, aim for mid-May; and in zone 4 areas, wait until late May or early June. For a fall crop, sow or transplant again in late July through August so the plants size up before the first hard freeze in September, October, or early November depending on location.
How to plant
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Choose the warmest, brightest site.
Pick full sun with at least 6 hours of direct light, and use a spot sheltered from north wind. In Michigan, a south-facing bed beside a fence, garage, or shed warms earlier in spring and holds heat longer in fall. Good drainage matters because cold, wet soil slows growth and rots young roots. -
Prepare rich, loose soil.
Work compost into the top 8 to 10 inches of soil before planting. Collards grow best in fertile ground with steady nitrogen, so mix in a balanced vegetable fertilizer if your soil test shows low fertility. Keep the bed slightly raised if you garden in heavy clay, which is common across much of Michigan. -
Wait for soil to warm enough.
Plant when soil temperature reaches about 45 to 50°F for transplants and 50°F or warmer for direct seeding. Cold soil stalls collards, and chilled seedlings sit instead of growing. In northern Michigan, a simple soil thermometer prevents you from planting into a bed that still feels like April below the surface. -
Harden off seedlings before planting.
Move nursery-grown or home-started seedlings outside for 7 to 10 days before transplanting. Start them in partial shade for a few hours, then increase sun and wind exposure each day. Michigan spring weather swings hard, so hardening off prevents shock when a sunny afternoon turns into a cold night. -
Transplant at the right spacing.
Set plants 18 to 24 inches apart in rows 24 to 30 inches apart. Bury seedlings at the same depth they grew in the pot, then water deeply to settle soil around the roots. If a late frost threatens after transplanting, cover the bed with lightweight row cover or a low tunnel before sunset. -
Direct sow only for the late-summer crop.
Sow seed 1/4 to 1/2 inch deep and thin plants to 18 inches apart after emergence. Direct seeding works best from late June through August when soil is warm and germination is quick. For spring harvests, transplants beat direct seeding because Michigan’s cool soil slows seedlings for too long. -
Mulch after the soil has warmed.
Once plants are established and the bed is warm, add 2 inches of straw or shredded leaves between rows. Mulch holds moisture and keeps mud off the leaves, but wait until after the last cold snap so you do not trap cold, soggy soil around new roots. In fall, an extra layer of mulch helps steady root temperatures before the first hard freeze.
Care through the Michigan year
In April and May, keep young collards covered if nighttime lows drop below 32°F. A floating row cover adds several degrees of protection and keeps transplant shock down. Water consistently so roots expand fast; uneven moisture produces bitter, tough leaves and slow recovery from cold snaps.
In June and July, collards build size quickly if you keep them evenly watered and fed. Side-dress with compost or a nitrogen-rich organic fertilizer once plants are growing strongly, especially after heavy cutting. Heat in southern Michigan can push collards to grow faster and taste a little stronger, so harvest often to keep new leaves tender.
By August and September, start your best fall planting. Collards often taste best after nights cool down, and Michigan’s first hint of autumn improves leaf quality. This is also the time to watch for early brassica protection so a surprise cold snap does not wreck your newest planting.
In October and November, pick the outer leaves before a hard freeze. Mature collards shrug off light frost, but repeated hard freezes blacken foliage and stop new growth. If you are in zone 6 southern Michigan, a low tunnel or row cover can keep plants producing several weeks longer than exposed beds.
In winter, collards in the open ground are finished across most of Michigan. Pull dead plants, clean out diseased debris, and leave a thick mulch on the bed only after the ground has frozen if you plan to use the space for next season. If you want fresh greens past snowfall, your best option is a protected structure and winter greens under cover, not open soil.
Common problems in Michigan
Late spring frost. New transplants get blackened, limp leaves after a 28 to 32°F night. Cover plants with row cover, buckets, or a low tunnel before sunset, and water the soil earlier in the day so it releases heat overnight.
Frost heave. Repeated freeze-thaw cycles push young plants up out of the soil, leaving exposed roots and wilted foliage. Press plants back firmly into place and mulch after the ground settles and freezes; in sandy or loose soil, a collar of soil around the stem base helps anchor them.
Flea beetles. Tiny shot holes across leaves show up fast in warm May and June weather. The first response is floating row cover right after transplanting, because once the beetles arrive the chewing starts immediately and ruins young plants.
Cabbage worms and imported cabbageworm caterpillars. Ragged holes and green frass on leaves point to larvae feeding from the underside. Hand-pick them early or use a labeled biological control while plants are still small; a covered bed prevents most damage in the first place.
Harvest or bloom timing
You can start cutting collards in June or July from spring transplants, then keep harvesting through September and October. In southern Michigan, a fall planting often gives the best flavor because cool nights sweeten the leaves before hard frost. Harvest the outer leaves first and leave the center growing point intact so the plant keeps pushing new growth until winter stops it.
When to ask for help
If leaves yellow from the bottom up, growth stalls even in warm weather, or the whole plant collapses after a cold night, contact Michigan State University Extension or a local nursery for a soil test and frost-damage diagnosis. Those signs point to a root problem, nutrient deficiency, or freeze injury that needs a local read on your bed conditions.
Frequently Asked Questions
Can I grow collards in the colder part of Michigan, including the Upper Peninsula?
Yes. In the colder part of Michigan, including the Upper Peninsula, you grow collards from transplants and treat them as a fast annual. Set them out later, after the soil warms, and use row cover for cold nights. A south-facing bed with good drainage gives your Michigan collards the heat they need to keep moving.
What should I do if a late spring frost hits my Michigan collards?
Cover your Michigan collards before sunset with floating row cover, a low tunnel, or even buckets for a short frost. Water the soil earlier in the day so it releases heat overnight. If young leaves blacken, remove damaged growth and let the plant recover from the center as temperatures rise.
Will Michigan collards come back after a hard winter?
No. Michigan collards do not survive hard winter freezes in open ground, and exposed plants stop producing once repeated deep cold sets in. Harvest them before that point, or move your plan into a protected structure. For extending harvests, winter greens under cover keeps you growing longer.
Can I push the Michigan collards season with a cold frame?
Yes. A cold frame gives Michigan collards extra protection in fall and can keep them producing several weeks longer in zone 6 southern Michigan. Keep the frame vented on sunny days so the leaves do not overheat, then close it before freezing nights. Use it to shelter established plants, not tiny seedlings.
Where do I buy collards in Michigan?
Buy collards in Michigan from local nurseries, garden centers, and farmers’ market plant sellers that carry cool-season vegetables. Ask for transplants suited to short seasons, since that gets you farther than starting late. If you want seed, choose a Michigan garden center with brassica seed racks and buy early in spring.