By Erin Marissa Russell
Gardeners who know how to store plants in the winter don’t have to start all over again when springtime comes around. Read on to learn when to put your plants up for the winter and how to do it so that they last all year round.
Can plants survive over winter?
Plenty of plants, such as trees and shrubs, turfgrass, bulbs under the ground, and perennials, are made to last through the winter. But your annuals and many other plants will need some extra care to make it through the winter. There are short-term ways to protect your plants through an uncharacteristic cold snap.
However, when temperatures fall lower than 28 degrees Fahrenheit for more than five hours, the water inside a plant’s cells will freeze into ice crystals. Those crystals have jagged edges, which can slice through a plant’s leaves and stems, causing cold damage or death. That’s why many plants need some help from you to make it through the cold winter season.
How do you store plants over winter?
For plants that need extra care to survive the winter that you won’t be digging up to store elsewhere (and those not in containers that are easily moved), there are ways to extend their life. These include hot caps or cloches and row covers (or the DIY version: blankets draped over vulnerable plants).
For a more permanent solution, gardeners can build a cold frame, which works like a miniature greenhouse to keep plants warm and safe. And of course, for the ultimate in winter protection, there’s nothing like a greenhouse to keep plants thriving all year round.
Can potted plants survive winter?
As a rule, potted plants face the same chance of damage from winter’s cold temperatures as other plants in your garden. As a matter of fact, the layer of soil on the ground tends to hold heat in better than the limited amount of soil in containers, so potted plants may be more vulnerable to damage or death due to cold temperatures.
That’s why a plant that’s listed as hardy to your gardening zone may not survive the winter when you’re growing it in a pot. In order for a plant to survive in a container over the winter, you’ll need to choose plants that are rated for hardiness at least two zones colder than your own location. If plants are hardy to your own zone, though, there are things you can do to help them make it through the year. Try burying the plant, container and all, in the ground so it can enjoy the insulating benefits of the soil. You can also dig up bulbs and store them as directed later in this article in the section for tropical plants or move the containers to a sheltered location indoors where they’ll still receive sunlight as they go dormant for the winter.
Whatever method you choose to keep plants alive, put that plan into place for potted plants before the first freeze of the year. Freezing temperatures can kill potted perennials all the way down to their roots.
How do you store perennials in the winter?
For perennial plants, you just need to entice the plants to enter their dormant stage so they can make it through the winter. After the first several hard frosts in your region, add protective layers of mulch, such as straw, leaves, or other organic material. Mulching your plants too early in the fall can make them a target for rodents looking to nest in the mulch material, so be sure to wait until a few frosts have passed.
How do you store tropical plants in the winter?
Tropical plants such as caladium, calla lily, canna, dahlia, ginger, and tuberous begonia grow from bulbs that live underground. It’s simple to care for these plants over the winter. Once the temperatures at night have dropped to reach the low 40s or high 30s Fahrenheit, plants will begin to exhibit browning on their leaves as these areas begin to die. Avoid this damage by taking the cooler weather as your cue to dig up the bulbs and store them for the winter.
Shake off and remove any dirt clinging to the bulbs, then place them on newspapers and store in a shed, patio, or other protected location to cure for a few days. Cut off the top growth and store the bulbs in a box packed well with dry peat moss or vermiculite. Find a safe place to store your bulbs in their box where temperatures will stay between 35 and 50 degrees Fahrenheit. Plant the bulbs again when spring rolls around for healthier plants with larger bulbs and more proliferation.
How do you store potted trees in the winter?
Trees that are young or have light-colored bark will be more substantially affected by the cold than more mature trees or varieties with darker bark. To offer trees some protection from winter sunscald, you can wrap the trunks in burlap or apply a coat of whitewash. These tactics will protect trees from slight variations in temperature, but for species that will face temperatures lower than what they’re hardy to, you’ll need to take further action.
If you have the space, you can bury your potted trees in the ground while still inside their containers, then apply a protective layer of mulch across the top. Trees that can survive indoors with limited sunlight can simply be moved into a garage, patio, or shed. You’ll want to do a bit of research to make sure spending the winter with a little less sun won’t hurt your trees if you choose this method. As a rule of thumb, trees rated above zone 7 can’t be stored in this way. The final option is to make a warm enclosure by building a miniature fence around your trees using chicken wire, then stuffing the enclosure with mulch or hay to protect the tree from cold damage.
How do you store roses in the winter?
Roses need a little help from the gardener to keep them dormant through winter’s freezing temperatures. Grafted roses, such as hybrid tea varieties, need the spots where grafting has occurred to be covered with soil in order to survive. After a freeze or two has come through your area, pile up a mound of soil around the base of your rose plants at least a foot deep to keep them insulated from the winter freezes.
Rose varieties that haven’t been grafted, such as rugosas or antique roses, don’t need quite as much protection. A layer of mulch a few inches thick on the ground around them will do the trick. Just spread a layer of straw or shredded leaves or other mulching material to offer them some protection.
You’ll need to get a bit more hands-on with climbing roses to ensure they survive the winter. Pull down the canes and lay them horizontally on the ground. Cover the canes with a layer of soil at least six inches deep. You’ll also need to pile up a mound of soil that’s a foot deep around the base of the plants so they’re protected against the cold. If your area sees temperatures lower than -10 degrees Fahrenheit, leave the canes where they are, but add another layer of insulation, such as straw, burlap, or old blankets, to cover them in the ground.
With all the ways to keep plants alive over the winter, there’s no reason to say goodbye to your favorite specimens or settle for purchasing new plants again in the spring. All it takes to store plants in the winter is a little preparation and planning and a bit of work before the real cold sets in.
Want to learn more about storing plants in the winter?
The Old Farmer’s Almanac covers How to Overwinter Your Plants
BioAdvanced covers Benefits of Frost Covers for Plants
Davey covers Winterizing and Storing Potted Trees
Chicago Tribune covers How Cold Affects Plants
Gardening Know How covers How to Protect Outdoor Plants in Winter
The Spruce covers How to Overwinter Container Plants