Your Plant’s Not Dead; It’s Dormant

  • Difficulty Rating: Beginner
Your Plant’s Not Dead; It’s Dormant

Plants that live for more than one season are generally called perennials, and all experience dormancy to some extent. Perennial plants may be herbaceous – meaning all of their top growth shrivels by winter as with Paeonia, Alstromeria and Gallardia.

My mother-in-law had an incredible green thumb. Among other things, she grew some of the most floriferous orchids I’ve ever seen. When she passed away, her garden suffered. A few years after she passed, I spent an afternoon helping dispose of dead plants and give a bit of nurturing care to those that were surviving. My father-in-law, who has no real interest in gardening, was concerned about one plant in particular. From his point-of-view, he killed it every year, yet it miraculously came back to life a few seasons later – every time. In reality, this sweet little Japanese maple was simply going dormant in winter and emerging from dormancy the following spring.

Your Plant’s Not Dead, It’s Dormant - image 2

Plants that live for more than one season are generally called perennials, and all experience dormancy to some extent. Perennial plants may be herbaceous – meaning all of their top growth shrivels by winter as with Paeonia, Alstromeria and Gallardia. Or they may be woody like maples, barberry and hydrangeas – meaning they drop their leaves for winter, but twigs, trunks and stems remain alive above ground as roots thrive below the soil line. In both cases, these long-lived perennial plants are not dying for winter only to be reborn in spring. Rather they are fully alive under ground, and in woody plants, in their stems. Their growth systems have slowed down, and they are drawing energy from reserves stored in their roots and to some extent, in their branches. By reducing their mass through shedding their top growth, slowing their food-making factories, and huddling their resources in minimal appendages, they are better able to protect themselves from the harsh environment winter brings.

Some plants – like cypress, camellia, pine and other evergreens – do not experience dormancy in the way the aforementioned perennials do. Instead, they continue to photosynthesize throughout the year. However, even they slow down production in very cold weather.

And just to be clear: annuals are plants that live for only one season, during which time they produce seed, from which their progeny will emerge in the following year. The annual plant itself does die at the end of a season, and it won’t come back to life. Only its seed will provide the next generation.

Seed head in the garden

To care for most herbaceous perennials like tall phlox, bee balm, rhubarb and sedum, cut any withered top growth (aka the dead parts above the soil line) to the ground before the garden is blanketed in snow. If they happen to have seed heads, consider leaving those intact until wild birds finish harvesting those snacks in winter. Just be sure to remove all of that spent top growth before the plant begins to send new stems upward from the roots in spring. Leaving past season detritus intact can harbor pests and disease.

To care for many deciduous, woody perennials like maples, deciduous azaleas, and crape myrtles, allow the plant to draw nutrients from the leaves in autumn. This process is what fills your garden with fall color, and provides the plant itself with extra food reserves through winter. Once the spent leaves drop to the ground, either keep a fine layer in place to help protect roots in winter or rake them up for the compost pile. If you choose to remove them in fall, be sure to apply a layer of composted mulch over your garden beds to provide nutrients and protection through winter. If you leave them in place, be sure to remove them in spring or you may have a bumper crop of pests and disease that overwinter with them.