As autumn progresses and the weather cools, it's time to get your garden ready for the winter. It may seem like not much is happening in your yard as you watch deciduous trees and shrubs drop their colorful foliage and other plants slow their growth as they prepare to go dormant. However, there's a lot going on under the soil until it freezes. This is especially true for newly transplanted trees and shrubs, divisions of perennials, and hardy spring bulbs, which all need to grow new roots to anchor themselves. Earthworms and various microbes in the soil are also still processing organic material into nutrients plants need to fortify themselves for the winter. While nature has its own ways of coping with the cold, dark months, we rounded up the top five things you can do to help prepare your plants for winter.
1. Mulch Your Perennials
Perennials return year after year, as long as they are hardy in your area. Each species handles cold differently so it is helpful to know which hardiness Zones a particular plant is rated for and which Zone you live in. In general, perennials that are hardy in your area won't require much effort from you to prepare them for winter. In regions that experience a lot of freezing and thawing, frost heaving can cause plants to get pushed out of the ground. To prevent this, add a 6-inch-thick layer of chopped leaves, straw, or other mulch around your perennials once the ground has frozen. This will help even out the soil temperature, especially if your area doesn't always have snow covering the ground throughout winter.
Sometimes the plant's own dead leaves help protect its crown and roots from the cold, so go ahead and leave them in place until next spring. Many perennials (such as sedums, purple coneflowers, and ornamental grasses) have forms that are interesting through winter, and their seeds help feed birds and other wildlife too. But if you prefer a tidier garden, it's fine to cut your perennials to the ground after frost has withered their leaves. Just make sure to add a layer of mulch to help protect them.
Related: Prepping Perennials for Winter
2. Extend Your Annual Display
Unlike perennials that return each year, annuals live only one season in the garden and can't survive freezing temperatures. Some are known as cool-season annuals, meaning they prefer to grow and bloom when temperatures are cooler. These include ornamental kale, blue lobelia, and snapdragons. Warm-season annuals, on the other hand, like it hot. Zinnias, French marigolds, and impatiens fall into this category. But you can extend the life of both types of annuals by keeping polyspun garden fabric handy to cover them during light frosts. Continue to water annuals until frost kills them. If your annuals are in containers, move them into a garage or other protected space when temperatures are forecast to dip into the 40s overnight. You can do this until daytime temperatures no longer rise above that threshold.
3. Dig Up Tender Bulbs
Fall is the time to plant hardy spring-blooming bulbs, but there are other types of plants known as tender bulbs that you may want to dig up if you live where the ground freezes. These include popular summer-bloomers like gladiolus, cannas, and dahlias. If you want to save these plants for another year, after frost has turned their leaves brown, gently dig them up and cut away the leaves. Brush off any excess soil, but don't wash them with water because excessive dampness can cause them to rot during storage. Let them dry in cool spot for a week, then pack them in a breathable container such as a cardboard box. Cover them in sawdust or old newspapers so bulbs don't touch, and place in a garage, basement, or other location that will not freeze but will stay below 45°F.
Related: Storing Tender Flower Garden Bulbs
4. Pamper Trees and Shrubs
Your trees and shrubs will have an easier time getting through winter if you make sure they are in good shape. For both evergreen and deciduous species, one of the most important things is to give them plenty of water before the ground freezes, especially if autumn has been dry. After the ground freezes, spread organic material such as chopped leaves up to 6 inches thick. This helps keep moisture in the soil (plants need water even during winter) and protect roots from freezing and thawing. Trim away any broken, damaged, or diseased limbs to prevent snow and wind from making these problems worse. For young evergreens or broad-leaved types in exposed locations, shield them from drying winter wind with burlap screens or shade cloth shelters.
Related: Tree & Shrub Care Guide
5. Bundle Up Your Roses
Roses are so beautiful that it's difficult to begrudge them the attention they require over the growing season. As cool weather brings on their dormant period, one final job remains for you: getting them ready for winter. Some types of roses are hardier than others, so it's important to know which kinds you have. As a group, hybrid tea roses are the most vulnerable to winter cold and need the most preparation; the easiest roses to grow and care for are shrub roses. Make sure to give all your roses plenty of water before the ground freezes, but do not fertilize or cut them back. To protect the root balls from frost heaving, pile up extra soil around their base. In Zone 6 and colder, add a 6- to 12-inch layer of straw, leaves, or other mulch on top of the soil mound then secure with a circle of chicken wire.