Garden Landscaping 12 Plants Experts Say You Should Always Prune in Autumn Prune these plants in fall to keep them healthy throughout winter. By Samantha Johnson Samantha Johnson Samantha Johnson writes about the happy things in life—pets, gardening, home, family, food, and farm life—and thinks Mondays are the most wonderful day of the week. She spends her spare time reading seed catalogs and taking photos of her napping Corgi. She has over 20 years of gardening experience and is the author of nearly two dozen books. Editorial Guidelines Published on September 27, 2024 Close Photo: Getty Images When fall arrives, the garden abounds with tasks and to-dos to accomplish before winter. One important thing to add to your list is cutting back your perennials, which protects them from pests and diseases during winter. But keep in mind that not all plants should be pruned in fall, as pruning at the wrong time can prevent your plants from blooming next season. To help you get this gardening task right, we spoke to experts who shared which plants you should always prune in fall. Jan Johnsen, landscape designer and author of Gardentopia: Design Basics for Creating Beautiful Outdoor Spaces Laura Irish-Hanson, extension horticulture educator at the University of Minnesota Extension 12 Plants You Should Never Cut Back in Fall 01 of 12 Phlox Mariia Romanyk / Getty Images Phlox (Phlox paniculata) is a beautiful flower, but when summer is over you’ll want to do some work on the leftover foliage. "Summer blooming garden phlox is susceptible to mildew, and even the mildew-resistant varieties may be affected if there is a lot of wet weather," says landscape designer and author Jan Johnsen. If your phlox has powdery mildew, you should cut back and destroy all foliage and stems in the fall. If there isn’t a mildew problem, cut back the stems in late autumn. Zones: 3 to 8Size: 24 to 48 inches tall x 24 to 36 inches wideCare requirements: Full to partial sun; moist soil 02 of 12 Hostas Hosta lilies growing in planting bed. Moelyn Photos/Getty Images Members of the hosta (Hosta spp.) family are beloved for their fantastic ornamental leaves. The vibrant foliage makes the plant a great addition to the garden even when it's not blooming. But as lovely as hosta foliage is, it just doesn’t stand up well to autumn weather. "Cut back your hostas in late fall," says Johnsen. "Hosta leaves turn yellow and after the first frost, the leaves tend to become soft and mushy." Cutting off the dead leaves prevents disease, insects, and slugs from hiding in the foliage during winter. Zones: 3 to 9Size: 1 to 2 feet tall x 2 to 3 feet wideCare requirements: Shade; moist, rich soil 03 of 12 Chives Getty Images Chives (Allium schoenoprasum) produce purple spherical blossoms that bring a delightful cheer to the spring garden and attract pollinators. Cut your chive plants back during the growing season to encourage a fresh round of growth and to give them a healthy start next spring. Zones: 3 to 9Size: 12 to 18 inches tall x 12 to 18 inches wideCare requirements: Full sun; rich, well-drained soil 04 of 12 Daylily Jacky Parker Photography / Getty Images Daylily (Hemerocallis) is one of the first perennials to begin shooting up buds in spring, filling the landscape with attractive foliage and impressive blossoms. Daylilies look much better if you remove all the spent leaves when the growing season is over—doing so also clears the way for fresh buds to arrive next year. "During summer, daylily leaves support the beautiful flowers, but in the fall, the leaves start to look ratty," says Johnsen. "These dying leaves may harbor harmful slugs and more." For this reason, and to promote tidiness, give daylilies an autumn trim. Zones: 3 to 9Size: 24 to 48 inches tall x 24 to 36 inches wideCare requirements: Full to partial sun; well-drained soil 05 of 12 Yarrow Liudmyla Liudmyla / Getty Images Charming as yarrow's (Achillea millefolium) blossoms and unique leaves can be, they become crumpled and brown once winter weather arrives. To prevent this, trim back your yarrow plants in the fall so that your garden doesn’t look weedy—just take some care not to trim them all the way to ground level. Zones: 3 to 9Size: 2 to 3 feet tall x 8 to 12 inches wideCare requirements: Full sun; well-drained soil 06 of 12 Bee Balm bg walker/ Getty Images To attract pollinators and create a stunning flower display in your garden, you can’t miss with bee balm (Monarda didyma). Hummingbirds in particular think it is fantastic. However, when the days grow short, and the first frosts take down bee balm’s foliage, cut back all of the spent plant material to prevent it from becoming a breeding ground for powdery mildew. Zones: 3 to 9Size: 36 inches tall x 8 inches wideCare requirements: Full sun; well-drained soil 07 of 12 Chrysanthemum Rett Peek Mums (Chrysanthemum), with all their beautiful colors, are always a garden favorite come fall. But once the flowers are spent, cut back this plant to encourage growth next season. When pruning, leave about 1 to 2 inches of stem to help protect the roots from the cold. Zones: 5 to 9 when grown as a perennialsSize: 2 feet tall x 2 feet wideCare requirements: Full sun; well-drained soil 08 of 12 Iris yumehana / Getty Images The large blossom of an iris (Irish spp.) is a sight to behold in the garden. Leave the leaves for as long as possible to help the plant produce late-season energy, but once the foliage is limp and brown, cut back everything except for a little bit at ground level. Zones: 3 to 9Size: Varies; 12 to 36 inches tall x 24 inches wideCare requirements: Full sun; well-drained soil 09 of 12 Delphinium happykamill / Getty Images Delphinium (Delphinium spp.) plants are great for adding vertical height to your garden, but make sure to cut them back in the fall. Do so by removing most of the foliage after the first major frost, but leave a few inches near ground level for insulation. Zones: 3 to 7Size: 4 to 6 feet tall x about 18 inches wideCare requirements: Full sun; rich, moist soil 10 of 12 Goldenrod iv-serg / Getty Images Goldenrod (Solidago) can spread aggressively and is considered a weed by some, but other gardeners appreciate its delicate golden blossoms. That said, goldenrod loses its beauty once it has been hit by frost, so plan on trimming the plant back in fall—it will happily pop back up next year. Zones: 2 to 8Size: 2 to 3 feet tall x 8 to 12 inches wideCare requirements: Full sun; well-drained soil 11 of 12 Blanket Flowers Tom Meaker / Getty Images Reminiscent of large, vibrant daisies, blanket flower (Gaillardia aristata) adds a lovely warmth to the garden landscape. When the season ends, trim this plant right to the ground. But note that you can also leave blanket flower intact if you enjoy the look of the dried flower stems. Zones: 3 to 10Size: 24 inches tall x 24 inches wideCare requirements: Full sun; well-drained soil 12 of 12 Balloon Flowers Katrin Ray Shumakov / Getty Images Balloon flower (Platycodon grandiflorus) boasts bright, concave bell-like blossoms that fill the garden with color and whimsy. You can cut them back to ground level in fall when they're done blooming. Zones: 3 to 9Size: About 24 inches tall x 24 inches wideCare requirements: Full sun; well-drained soil There are plenty of plants you might want to leave intact over winter, thus forgoing the autumn cleanup. "Many seed heads are a source of food for birds and other animals during winter. The hollow stems of larger herbaceous perennials are used as overwintering sites for various insects," says Laura Irish-Hanson, extension horticulture educator at the University of Minnesota Extension. "If you feel inclined to cut the plants back to the ground, try finding a place hidden from view where you can leave those stems stacked until late spring." Was this page helpful? Thanks for your feedback! Tell us why! Other Submit