By Andrew Bunting, PHS VP of Horticulture 

With autumn coming to an end, and trees and shrubs with fall color dropping their last leaves, now is the perfect time to design a winter garden for the cold months. Both containers and window boxes can be decorated with living plants for the winter months to create an impactful winter garden. Despite very cold weather, there are a host of plants that won’t ‘bat an eye’ in the extreme cold and will provide great decoration and ornament throughout the winter months. 

Choosing the Best Outdoor Container for your Winter Garden 

Most types of pre-existing window boxes will be fine for planting with winter ornamental plants. However, not all containers can be used as outdoor container plants for winter. 

For containers being used on the front porch, patio, deck, etc. there are certain types that should be considered. Any type of plastic or fiberglass container will withstand the cold and freezing temperatures. Stonecast or concrete containers are durable too.  

Terracotta containers should be avoided. By nature, terracotta is a porous material. The tiny pores will undoubtedly absorb water and when the temperatures are freezing or below, these tiny pores will retain water and will freeze and expand. Over time, this will cause terracotta containers to crack and ultimately fracture.  Glazed containers in certain parts of the country where it is not extremely cold can also be used. 

Designing the Winter Container 

Planting a winter container is very similar to planting a summer container.  The first step is to select a number of decorative containers that will be able to withstand the cold and fluctuating temperatures.  

Next, select a variety of different kinds of plants including conifers, plants with nice stems and berries, and plants with colored or variegated foliage. Some bulbs can be added too. Fill the container about two thirds of the way full of potting soil. Even though it is winter, and watering will be minimal, it is still important to have a drainage hole in the bottom of the container.  

Add the plants to the pot and backfill with the potting soil. Leave about one inch from the top of the soil to the top of the container. Water the newly planted container thoroughly. Chances are, they may only need to be watered if we get some warm winter days. 

Winter Container Plant Ideas 

There are a myriad of outstanding plants that can be used for winter containers, including plants with interesting stems or bark (certain Japanese maples, dogwoods, willows, or birches), plants that retain their fruit during winter (winterberry holly), a variety of conifers (junipers, pines, spruces, firs, cedars) as well as plants with vibrant winter foliage or flowers. Additionally, winter planters can be augmented with planting bulbs that will emerge in the late winter such as daffodils, snowdrops, and snowflakes. 

Beautiful Bark 

Plants with interesting stems and beautiful bark can provide beauty in winter containers from December to March. Red-stemmed dogwoods have multiple upright stems that can brighten a container, and act as a great focal point.  Cornus sericea ‘Cardinal’ has beautiful salmon-orange stems that contrast nicely with conifers, especially those with blue or yellow foliage. Cornus sanguinea ‘Midwinter Fire’ is orange at the base of the branch and transitions to red.   

Many willows also have attractive stems including Salix alba ‘Chermesina’ with bright golden winter stems. Salix ‘Swizzlestick’ has twisted, corkscrew-like stems which add interest and architecture to the winter garden. Even at a young age, birches will have interesting bark, including selections of the paper birch, Betula papyrifera Renaissance Reflection® which has alabaster-white stems. 

Bountiful Berries 

Plants with an abundance of fruit are another perfect accent for winter planters. There are many selections of the winterberry holly, Ilex verticillata worth considering. ‘Winter Red’ and ‘Maryland Beauty’ have plump, shiny red berries and ‘Winter Gold’ has an abundance of salmon-orange fruits. In some winters, birds such as the American Robin, mockingbirds and the Grey Catbird might feed on the hollies. The American wintergreen Gaultheria procumbens has tight clumps of evergreen foliage covered in large red fruits. Because of its small stature, it is often used in small containers or window boxes. The native Northern bayberry Myrica pensylvanica has smokey blue fruits from the summer through the winter and can also be a food source for certain species of songbirds. 

Vibrant Foliage 

Bright or variegated foliage can make a visual “pop” in winter containers. There are several selections of the Adam’s needle Yucca including ‘Color Guard’ with spikey leaves that have green edges and a yellow center. In USDA zone seven or higher, there are also variegated selections of Fatsia japonica, another plant with stunning winter foliage. ‘Spider Web’ has a web-like white variegation over the surface of a dark green leaf. Additionally, many species of hollies have vibrant winter foliage including a selection of the Japanese holly Ilex crenata ‘Drops of Gold’ with bright yellow leaves and Golden Oakland™ with yellow and green variegated leaves. 

Essential Conifers 

Conifers are one of the best and most iconic choices for winter planters, in part because most conifers prove to be perfectly hardy and resilient to winter conditions. Many of the spreading cultivars of Juniperus horizontalis and J. conferta are perfect for spilling over the edge of the winter container, adding drama and shape. Many conifers also have great color - there are many selections of Chamaecyparis with striking yellow foliage, including ‘Crippsii,’ ‘Gold Mop,’ Soft Serve® and ‘Vintage Gold.’  Pinpoint® and ‘Boulevard’ have blue foliage.  

Winter Flowers 

Winter containers can be accented by winter flowering plants. There are dozens of winter flower cultivars of Helleborus including ‘Frosted Rose,’ ‘Mother of the Bride,’ ‘Josef Lemper’ and ‘Pink Frost.’  They are perfect for the edge of the container or in window boxes. A single specimen of a witch hazel will brighten any container from January to March. ‘Primavera’ has soft yellow flowers; ‘Jelena’ has coppery orange flowers, and ‘Strawberries and Cream’ has yellowish-orange flowers. Many cultivars of Mahonia have spikes of yellow flowers throughout the winter including ‘Arthur Menzies,’ ‘Charity’ and ‘Winter Sun.  

Certain very hardy bulbs, like the early flowering daffodil, Narcissus ‘February Gold’ or some of the early flower smaller bulbs like snow drops, Galanthus and snowflakes, Leucojum are also a nice addition. 

Embellishing Containers 

Winter containers can be embellished using a variety of materials including cut branches. Cut branches of big evergreens, or shiny leaves of the southern Magnolia grandiflora make for a nice addition. Pinecones and other dried fruits are another great ornamentation. Even cut logs, or stout branches of the paperbark birch can be a strong focal point.  

Tending to your Winter Containers Throughout the Season 

Thankfully, tending to your winter containers or window boxes does not need to be a significant chore. You should deeply water your newly planted container or window box, but otherwise, watering can be kept fairly minimal. If we have a string of unusually warm winter days or extended periods of drought, you should water your containers/boxes again to keep them looking their best.  

Preparing your Container Garden for Warmer Weather 

At the end of the season, while some of the plants might be a bit discolored and tattered, most of them will be alive, and can be removed from the container and planted in the garden where they can continue to be enjoyed in spring. Each winter, however, it is easiest to purchase new and different plants, and this also allows for some experimentation with design from year to year. When transitioning your containers or window boxes for spring/summer, the remaining soil can be left in and used for summer displays. 

Using containers and window boxes in the winter garden will create a bright and inviting display. Winter containers have become immensely popular with businesses to invite customers into their stores. At home, winter containers are extremely welcoming and beautiful for visitors, especially during the bleakest and coldest months of winter, and designing your winter container can be approachable and low maintenance. With many hardy plants to choose from to add interest to a winter container, this approach to winter gardening is a great way to keep your garden looking its best during the coldest, darkest months of the year, and will set you up well to bridge the gap between fall and spring displays.