As Michigan’s spectacular autumn colors begin to fade and those crisp October mornings hint at winter’s approach, you might be wondering what to do with all those perennials that have given their best throughout the growing season.
But which ones should you tackle with your pruners before the snow flies?
While it’s tempting to grab your garden shears and cut everything down to the ground, some plants benefit tremendously from fall pruning while others should be left standing until spring.
Today, we’ll look at 12 perennials that Michigan gardeners should cut back in the fall – and more importantly, why this timing makes such a difference for your garden’s health.
Since Michigan spans USDA hardiness zones 4a through 6b, from the frigid Upper Peninsula to the more moderate areas near Detroit and Grand Rapids, these recommendations will help gardeners across the Great Lakes state prepare their perennials for those long winter months ahead.
Related Article: 15 Perfect Michigan Perennials You’ll Love
1. Hostas (Hosta Species)
Let’s start with everyone’s favorite shade garden staple – hostas! These leafy beauties create such lush backdrops in Michigan’s many wooded gardens, but what happens when those first hard frosts turn their foliage into a mushy mess?
Michigan State University Extension specifically recommends removing hosta leaves, petioles, and stems in the fall. Why? Those decomposing leaves become perfect hiding spots for slugs and their eggs, not to mention creating cozy winter homes for voles and mice that love to munch on hosta crowns.
You’ll want to cut the foliage back to about 2 inches from the ground once it’s been blackened by frost. This prevents the crown from rotting under all that soggy organic matter and gives your hostas a clean slate for spring emergence.
2. Peonies (Paeonia Species)
Few plants create as much excitement in Michigan gardens as peonies, with their spectacular late spring blooms that can make even the most seasoned gardener stop and stare. But what is it about fall care that’s so crucial for next year’s display?
Peonies are particularly susceptible to fungal diseases, and Michigan State University Extension emphasizes removing all peony debris in the fall to reduce disease inoculum. Cut the stems back to about 2-3 inches from the ground once the foliage turns golden yellow – usually after our first hard frost in late October or early November.
This timing matters because the leaves continue photosynthesizing and feeding the roots until that color change occurs. However, leaving diseased foliage through winter guarantees problems next season, so proper disposal is key.
3. Bee Balm (Monarda Species)
Bee balm brings such joy to Michigan gardens, attracting butterflies, bees, and hummingbirds throughout the summer months. But even the most disease-resistant varieties can succumb to powdery mildew by season’s end – especially during our humid Great Lakes summers.
If your Monarda shows signs of that telltale white powdery coating, you’ll want to cut the entire plant back to just a few inches from the ground. This prevents the disease from overwintering and gives the plant a fresh start come spring.
However, if your bee balm stayed healthy all season, you can be more selective. Try thinning out some of the older stems while leaving the seed heads for hungry goldfinches during those lean winter months.
The birds particularly appreciate this gesture when snow covers other food sources!
4. Garden Phlox (Phlox Paniculata)
Those fragrant phlox clusters in cottage garden colors create such romantic scenes in Michigan landscapes. Unfortunately, they’re notorious for developing powdery mildew, particularly during our sticky summer weather patterns around the Great Lakes.
Cut back all foliage and stems in the fall, even if the plant looks relatively healthy. This dramatically reduces disease pressure for the following year – something particularly important in Michigan’s high-humidity climate.
You’ll want to dispose of the pruned material rather than composting it. Think of it as taking out the trash to prevent uninvited fungal guests from returning next season!
5. Daylilies (Hemerocallis)
Don’t let the name fool you – daylilies aren’t true lilies at all! These workhorses thrive in Michigan’s clay soils and variable weather conditions with minimal fuss. While they’re not prone to serious disease issues, cutting them back in fall saves you from a messy cleanup job when spring fever hits.
Daylilies respond beautifully to what gardeners call “shearing” – cutting all the foliage back to about 4 inches from the crown. This is particularly important in Michigan where they don’t remain evergreen through our winters.
Focus especially on removing any yellowing or damaged leaves, as these can harbor slugs and other pests if left to decompose around the plant base during our long, wet springs.
6. Bearded Iris (Iris Germanica)
Those spectacular bearded iris blooms that steal the show in late spring can become a real liability by fall. The tall, sword-like foliage flops over as the season progresses, creating perfect hiding spots for iris borers – definitely not something you want overwintering in your Michigan garden.
Cut the leaves back to about 6 inches from the ground, creating a neat fan shape. This removes potential pest habitat while leaving enough foliage to help the rhizomes continue photosynthesizing before dormancy.
Make sure to clean up all debris around the plants, as fallen leaves can harbor both insects and fungal diseases through Michigan’s variable fall and winter weather.
7. Astilbe (Astilbe Species)
These feathery-plumed perennials add such elegance to Michigan’s shaded gardens, thriving in our moist, heavy clay soils. But what should you do with those spent flower plumes as winter approaches?
While some gardeners love the rusty-brown winter interest astilbe provides, Michigan’s heavy snow loads and ice storms often flatten the stems anyway. Cut back to about 3 inches from the crown after the foliage has died back naturally.
This prevents the crown from being smothered under wet leaves and snow, which can lead to rot in Michigan’s freeze-thaw cycles. Clean removal also eliminates hiding spots for pests during our long winters.
8. Catmint (Nepeta Species)
Your feline friends aren’t the only ones who love catmint – Michigan’s abundant pollinators find it irresistible too! This drought-tolerant perennial responds beautifully to pruning throughout the growing season, and fall cutting helps tidy up plants that won’t survive our winters intact anyway.
Cut catmint back to about 3-4 inches from the ground after the first hard frost. The silvery-gray foliage simply won’t survive Michigan’s harsh winters, so getting ahead of the cleanup saves you work when you’re eager to see new growth in spring.
If you cut catmint back by half in midsummer (which encourages fresh growth and fall blooms), you might find less cleanup needed now.
9. Blanket Flower (Gaillardia × Grandiflora)
These cheerful daisy-like blooms in warm oranges and reds provide color right through Michigan’s first frosts. Blanket flower is remarkably hardy, but cutting back spent stems in fall improves vigor for the following season.
Trim plants back to about 4-6 inches from the crown, removing all the old flowering stems. This encourages the plant to focus energy on developing strong root systems rather than trying to maintain tired foliage through Michigan’s demanding winters.
If you’ve been deadheading throughout the growing season, you can leave some seed heads for winter bird feeding before doing your final fall cleanup.
10. Columbine (Aquilegia Species)
These delicate-looking perennials with their distinctive spurred flowers are surprisingly tough Michigan natives. However, they benefit greatly from fall cleanup, especially since columbine foliage often shows leaf miner damage by season’s end.
Remove all damaged foliage and clear away debris around the plant base. Columbine sends out fresh growth very early in Michigan springs, so fall cleanup prevents old, diseased material from interfering with new shoots.
To prevent excessive self-seeding (columbines are enthusiastic self-sowers), remove flower heads after blooming. Leave healthy foliage until after frost, then cut back to the crown.
11. Salvia (Salvia Nemorosa)
Perennial salvias create stunning vertical accents in Michigan gardens, with their spiky flower clusters attracting butterflies all season long. These tough plants benefit from several pruning sessions throughout the year to prevent flopping and encourage reblooming.
When fall arrives and blooming slows, cut the entire plant back to the new basal growth at the crown. This keeps plants tidy through winter and prevents old stems from breaking under snow loads and creating spring cleanup headaches.
Don’t confuse perennial salvia with annual varieties – we’re talking about the hardy Salvia nemorosa types that reliably return in Michigan gardens year after year.
12. Balloon Flower (Platycodon Grandiflorus)
These unique star-shaped blooms that emerge from inflated buds add such character to Michigan perennial borders. However, Michigan State University Extension specifically mentions balloon flowers as plants vulnerable to crown damage from rodents, making fall cleanup particularly important.
Cut back to about 2 inches from the ground after the foliage yellows and dies back naturally. Remove any leaf litter around the base to eliminate hiding spots for mice and voles that might otherwise feast on the fleshy roots during winter.
Balloon flowers are notoriously late to emerge in spring, so mark their location to avoid accidentally digging them up during early season gardening enthusiasm!
Why Fall Pruning Matters in Michigan
You might wonder why timing matters so much in the Great Lakes region. Michigan’s unique climate presents specific challenges that make fall pruning particularly beneficial:
Disease Prevention: Our humid summers followed by wet falls create perfect conditions for fungal diseases to overwinter in plant debris.
Pest Control: Michigan’s clay soils and abundant organic matter provide cozy winter homes for slugs, voles, and harmful insects.
Crown Protection: Our freeze-thaw cycles can cause serious crown rot when soggy debris accumulates around plant bases.
Snow Load Management: Heavy snow can crush and break stems left standing, creating more work and potential plant damage.
However, remember that not all perennials should receive the fall treatment! Plants like ornamental grasses, sedums, and coneflowers (Echinacea) provide valuable winter interest and bird food – leave those beauties for spring cleanup.
Timing Your Fall Cleanup in Michigan
The best window for fall pruning in Michigan typically runs from mid-October through mid-November, depending on your location within the state. Northern regions will need to work earlier, while areas near the Great Lakes might have a bit more time thanks to the moderating effect of large water bodies.
Wait for a hard frost to damage tender foliage, then choose a dry day for your pruning work. Use clean, sharp tools and dispose of diseased material properly – never compost material that showed signs of disease or pest problems.
Setting Up for Spring Success
By taking care of these 12 perennials now, you’re giving your Michigan garden the best possible start for next spring. Clean, healthy plants emerge more vigorously, encounter fewer pest and disease issues, and often reward you with more spectacular blooms.
Next spring, when you see those first green shoots pushing through Michigan’s thawing soil, you’ll appreciate the time you invested this fall. After all, successful gardening in the Great Lakes region is as much about working with our challenging climate as it is about choosing the right plants for our unique growing conditions.
