End of Season Tips: Cut Dead Plants or Pull Them Out?
Summers end invites rain, frost, and cool weather that zaps the life out of tender annuals. Your blooming garden may look brown, dreary, and dead this fall—but should you pull out those dying plants, leave them be, or chop them to the ground? Discover what you can do alongside seasoned grower Jerad Bryant.
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Once your plants stop performing, your initial reaction may be to pull them out of the ground; but is this the best thing to do in your garden? Pulling plant roots out of the dirt disturbs the sensitive soil microbiome that quietly grows below ground. Bacteria, fungi, and worm pathways break or cave in, and some die during the disturbance.
Sometimes you’ll want to pull up plants, like if you’re dealing with diseases or replacing dead annuals with new ones. There is no main rule for gardeners but a set of approaches for different garden conditions. We’ll discuss when or not you should cut, pull, or replace your ornamental species, and if you should leave them alone. Leaving things alone is often the best solution in most garden situations.
Natural processes handle many things better than we can, like decomposition. Instead of cutting plants and throwing them away, you might let them look ugly in the winter while they break down. They’ll disappear by spring, turning into crumbly, rich humus for your new plants. Some species also have unique winter interests with structural stems, seed heads, and dead foliage.
So, it begs the question: should you cut dead plants or pull them out? Let’s find out!
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Leave Perennials Be
Sometimes “dead” plants are alive! Herbaceous perennials die to the ground in autumn and winter, where they conserve their energy below ground in their roots and crown. Some die completely below the soil, while others keep some knobby stems above ground.
Perennials that die back completely, like columbines, daylilies, and herbaceous peonies, benefit from a trim in fall, although it’s not necessary for their health. Last year’s growth will decay over the winter and help feed next year’s growth in spring. Trim the perennials that die back completely if you wish for aesthetic purposes. A good trick is to leave an inch or two of dead stems. That way, you’ll know where your dormant plants are when they’re not actively growing.
Some herbaceous plants keep above-ground growth alive through fall and winter. They sprout new shorts from their crown or keep short stems that persist above ground throughout winter. Either way, they’re more frost-tender, and cutting them back can hurt their winter survival chances. These are some common perennials to leave until spring:
Common Name | Scientific Name |
Mexican Feather Grass | Nassella tenuissima |
Garden Mums | Chrysanthemum x morifolium |
Red Hot Poker | Kniphofia uvaria |
Purple Coneflower | Echinacea purpurea |
Hardy Fuschia | Fuchsia magellanica |
Ornamental grasses, native wildflowers, and perennials with persisting seed heads offer ornamental interest no matter the season. Mexican feather grass, fountain grasses in the genus Pennisetum, and silvergrass are some grass examples that keep unique seedheads that persist in rains, freezes, and snowstorms.
Cut Back Disease-Prone Species
Two main garden perennials need cutting back annually at the end of summer since their dead foliage allows diseases to persist in your garden. Phlox and bee balm keep powdery mildew spores on their leaves. The spores can spread to neighboring tender, young foliage in early spring.
Remove these perennials’ above-ground growth as low as possible. They’ll resprout in spring from their roots, free from powdery mildew. Bee balm, or Monarda, spreads through runners like mint; you may pull these up in the fall to limit your plant’s spread.
Some crops overwinter powdery mildew, like squash, watermelon, and muskmelons. Remove their dead parts from your garden in the fall, cutting them at the soil level so their roots decay. Old leaves, stems, and fruit can hold onto nasty spores—put them in a hot compost pile or dispose of them in your yard waste bin.
Let Dead Annuals Decay
Frost-tender annuals die as soon as freezing temperatures arrive. Snow, wind, and ice put an end to their proliferous blooms and beautiful foliage. Annuals like petunias, marigolds, and coleus will look rotten and black, like they need cutting back.
You have two options here that boost biodiversity in your garden: cut the dead parts off and compost or mulch them, or leave them be. Native annuals break down in nature without any landscaper coming through to cut them down. They simply brown, rot, and morph into nutrients that plants can use again.
If you’d rather have a tidy garden, cut back annuals to the base of their trunk after they die. Cutting them, rather than pulling them, leaves roots in the soil that decay and create pathways for worms. The empty air channels also feed microbes with consistent water and air. Layer the dead cuttings over your garden beds as mulch, or put them in the compost.
Compost Dead Plants
An easy way to recycle all the dead plant cuttings is with compost. A pile is an efficient way to recreate the natural decomposition process of wild spaces. You create an ideal home for the microbes to live in, and they’ll move in and feed on any decaying organic matter you give them.
Create a compost pile by stacking equal parts “greens” and “browns.” Greens are fresh organic matter rich in nitrogen, like kitchen scraps, green plant clippings, and manure. Browns are carbon-rich, dry materials like dead leaves, straw, and small twigs. Water the pile so it’s moist but not soggy, and turn it once every day or two.
With continuous moisture, turning, and a balanced ratio, hot compost piles create usable soil in a couple of months. There are other, easier options for composting, like cold piles and bins. Find the style that works for you, and you’ll have an easy waste recycler ready in your backyard.
If you’re removing invasive plants, remember not to compost these, as they can propagate in your compost pile and spread throughout the garden.
Replace Summer Annuals
Instead of removing or cutting, you can also replace annuals! Some plants, like pansies, ornamental kale, and hellebores, are marginally frost-tolerant in cold winter zones. Pull up your old, dead annuals and plant these species down instead. They’ll thrive in cold, wet weather and give you colorful blooms until concurrent hard frosts arrive.
Fall annuals may not be your best option if you have early hard frosts in autumn. Instead, plant spring-blooming bulbs that stay warm underground all winter. Daffodils, tulips, and lilies are perfect for this. They’re hardy, easy to care for, and they last many years in your landscape.
If you pull up your summer annuals without replacing them, put compost or mulch in their place. These amendments protect the soil and add beneficial microbes and nutrients where they decompose. By spring, they’ll create humus-rich homes for new perennials or annuals.
Protect Bees and Beetles
Native plants often provide valuable shelter for insects and bugs like ladybeetles, bees, butterflies, and moths. They use dead leaves, stems, and roots as protection from predators and freezing winter elements.
Common native landscaping plants like purple coneflower, black-eyed Susan, and blazing star grow tall flowering stems that stay brown and dead from fall to spring. Why should you leave the stems? They have hollow spaces in them that bugs and beetles hide inside. Larvae, adults, and eggs are in most hollow stems you see in gardens.
Bolster biodiversity this fall by leaving native wildflowers—letting them have dead parts won’t affect their flowering period next spring. You can safely cut back stems in mid or late spring after new shoots sprout out of the ground; most bugs will have safely flown off in search of friends, food, or water.
Feed Local Wildlife
Not only do dry stems offer shelter for tender bugs but the seed heads that persist feed squirrels, birds, and small mammals when most other foods freeze or rot. You remove a valuable food source if you cut these stems down.
Some animals take a few seeds and leave the rest for later. They’ll return again and again until they eat up all the seeds. The heads will be empty when spring arrives, and you can cut them back as new sprouts emerge from the ground.
Empty seed heads are also excellent materials for floral bouquets and dry arrangements—they’ll last for months if not years! Cut them before rainstorms arrive, and dry them upside down in an area with good airflow. Yarrow is one model perennial for dry flower arrangements, as their heads last a year or longer.
Key Takeaways
- Cut back summer annuals and use their debris in compost or mulch on top of the soil.
- Leave perennials unless they go dormant underground and you prefer a clean, tidy look in your garden.
- When cutting perennials back, leave an inch or two of stems above the soil so you remember where your plants are.
- Instead of pulling up summer annuals, replace them with bulbs, cold weather annuals, or perennials.
- Old, dry seed heads and stems feed wildlife and create valuable habitat space; leave these parts alone so local animal species thrive.