Winter is one of the most rewarding times in the garden and landscape. Gone are the weeds and heat of summer. Instead you can kick back and enjoy your garden as a backdrop to the holidays. Many people forget about their gardens after the last colorful leaves drop. Gardens, however, can be beautiful year-round with a little thought and planning.
Evergreens, grasses, perennials, yucca and agaves, with good winter texture, make the landscape just as pleasing as during the growing season. We are lucky here along the Front Range that our semi-arid climate allows us to grow a wide variety of plants that look great through the winter. Our dry climate also tends to freeze dry grasses and perennials making them last until February or March when it is time to start cleaning up the garden for spring.
The Plant Select program, which is run by the Denver Botanic Gardens and Colorado State University, has several wonderful plants that stay green all year: Cercocaprus intricatus (littleleaf mountain mahongy), Arctostaphylos (mock bearberry manazanita, and Panchito and chieftain manazanita), Juniperus `Woodward’ (Woodward columnar juniper), Picea glauca ‘Pendula’ (weeping white spruce), pinus monophyla (blue jazz pinyon pine). All of these enjoy good drainage, full sun to part sun and minimal water once established. All but the weeping white spruce are truly xeric, or very dry, once established. If you have some shade, and water more frequently, then use Alleghany viburnum, weeping white spruce and Paxistima canbyi (mountain lover).
Plant Select helps gardeners find plants that thrive in the intermountain region and high plains. Many of the plants require less watering and can grow in different climates. To learn more, visit www.plantselect.org.
Plant Select has worked hard to bring us some great grasses. Muhlenbergia reverchonii (undaunted ruby muhly) is my favorite at 2-3 feet tall and wide — it’s the most beautiful grass on the market and looks good until March. Bouteluea gracilis `Blonde Ambition’ (Blonde Ambition gramma grass) and Schizachrum scoparium `standing ovation’ (standing ovation little blue stem) are also great smaller grasses. If you need a large grass for a hot dry spot, try Sporobolus wrightii (Giant sacaton). This is a good substitute for Miscanthus or hardy pampas grass.
Shrubs and trees provide the backbone to a garden. Ranging in size, the following plants add texture or winter interest in the form of berries and bark. Cratageus ambigua (Russian hawthorn), Heptacodium miconoides (seven sons flower) are small trees that have beautiful form and offer interesting bark and reddish berries on the hawthorn, or reddish seed heads on the Heptacodium.
Chrysthomanus baby blue (baby blue rabbit brush) is a superb small mounding shrub for hot sunny areas and would blend beautiful with any of the plants mentioned.
Artemisia `seafoam’ (seafoam sage), Artemisia `Powis Castle’ Eriogonum umbellatum `Kannah Creek’ (Kannah Creek buckwheat), Delosperma nubigenum, Sedum sediformi (turquoise tails blue sedum) and Sedum `Angelina’ are great perennials with some winter color for sunny dry gardens that look nice with the other plants in this article.
Agave neomexicana, yucca harrimanie (doll house yucca), yucca rostrata and Heperaloe parviflora add structure and color to the winter landscape. You can use them as focal points to contrast against the finer textures of the above plants.
With a little thought and work, your garden can be just as beautiful in December, January and February as it was during the growing season.
Mike Kintgen is the curator of alpine collections at the Denver Botanic Gardens. He can be reached at horticulture@denverbotanicgardens.org.