The Winter Landscape Part Four: Evergreens
by Elaine Christen
Of all the plants one can have to provide interest in the winter landscape, evergreens offer the most substantial forms. From classic pyramidal trees to lower growing shrubs and ground covers, evergreens can bring life and color to the frosty scenes of winter.
The fact that they keep their foliage or needles actually makes some evergreens a little more challenging to winter over than deciduous plants. Broadleaf evergreens like boxwood or rhododendrons are susceptible to breakage and crushing by snow loads, and can also transpire (breath) more moisture than they can absorb. Newly transplanted needled trees such as spruce, fir and pine shed rain and snow off their outer drip line where the smaller root ball can’t access the moisture. Needled trees also transpire, but at a slower rate than broadleaf evergreens.
These pitfalls are easy to avoid. By deep watering several times in fall through the end of October, the ground will have ample moisture in place before the frost layer locks out any more. Another way to ensure winter survival, especially of new transplants, is the use of an anti-transpirant. Anti-transpirants such as Wil-pruf, coat the needles or leaves with a film that slows down transpiration, preventing winter desiccation. They are simple to apply with a spray bottle.
As far as avoiding snow-caused breaking and crushing, here are two strategies to employ. Place susceptible plants in areas where roof or snow-blower condensed snow does not accumulate. If plain heavy snow is a problem, try pounding rebar stakes in a triangle within the branch structure halfway between the main stem and the outer perimeter of the plant. Before a big snow occurs, use strong twine to encircle the plant, gently pulling the branches upward and inward with the rebar for support. This gives the plant the extra strength it needs to hold up under the weight of the snow. Release the twine in late winter so the branches can relax to their natural shape.
When designing with evergreens, as with any plant, one of the most important considerations is that of mature size. Those five gallon spruce trees might look just right flanking your walkway, but when they start to take off and get fifteen feet wide, there will no longer be a walkway, just two trees squished together. Always design with the mature size in mind. If the layout seems a little sparse, fill in with easily moved perennials rather than planting permanent anchor plants too closely.
Evergreens are useful for bringing vibrant green (or blue or yellow) color to the landscape in an otherwise austere season. Having some evergreen shrubs near the entrance of a home can look much more welcoming in winter than just dormant twigs. If you have the space in your lawn, a large evergreen tree makes an excellent focal point along with providing safe haven for songbirds. Evergreen groundcovers provide that touch of green when the lawn is a sad tan.
Think of evergreens as “anchor” plants, providing the framework around which to design your landscape. Below are listed some good choices in three categories with an abbreviated description of each.
Colorado Blue Spruce, 40-60’ tall x 10-20’ wide. The shade of blue depends on seed stock. For bluest tree, choose a variety grown from cuttings such as ‘Hoops’ or the short and wide ‘Fat Albert’. All are hardy in zones 2-8.
Black Hills Spruce, 20-25’ tall x 10-12’ wide is easier to fit into the average sized yard. The bright green new needles mature to a blue-green color. Zones 2-8.
Subalpine Fir, 60-100’ tall x 2-5’ wide. Extensively planted in our area, this tree looks cute and Charley Brownish when young, but thickens up and grows tall faster than most people expect. In 20 years, the tree will reach 15-25’, so it will take three or more generations to reach its mature height. Hardy in zones 4-7, it suffers in hot, dry summers. Consistent irrigation is essential to success.
Concolor (or White) Fir, 40-50’ tall x 15-20’ wide. Concolors are similar in appearance to Blue Spruce, but with longer, very soft needles. Hardy in zones 4-7, it appreciates consistent moisture but is more drought tolerant than the Subalpine fir.
Vanderwolf’s Pyramid Limber Pine, 15-20’ tall x 8-12’ wide. With a dense, compact habit and bluish, twisted needles, this is a tree with good color, texture and size. There is also a weeping variety that gets about 10’ tall and 6’ wide called Weeping Limber Pine that looks particularly good next to water features. Zones 4-7.
Austrian Pine, 40’ tall x 20-30’ wide. This pine was introduced in this country in 1759 and has been valued for its dark green color and extreme toughness ever since. Pyramidal in youth, it gets a flattened crown at maturity. As with most pines, the lower branches die as the tree matures, so the tree takes on the profile of a deciduous shade tree. Zones 4-7.
Hick’s Yew, 8-10’ tall x 3-5’ wide. Short, deep green needles, a dense habit and tolerance of shade and shearing make yews the ultimate hedge plant. Its cousin, the Dark Green Spreader Yew gets 3-4’ tall x 4-6’ wide. There are many other variations as well. They all bear fleshy scarlet berries which are poisonous so take care in placement of these plants. Zones 4-7.
Boxwood, size varies. A classic hedge plant with its bright green, small oval leaves, boxwoods look equally charming unshorn. Winter Gem gets 2-4’ tall and wide, Dwarf English just 1-2’ tall and wide, and Green Mountain gets 5’ tall x 3’ wide. Boxwood can take some shade and is hardy in zones 5-9.
Compact Oregon Grape Holly, 2-3’ tall x 3-4’ wide. This plant has reddish new growth, masses of yellow flowers in spring, glossy deep green foliage in summer accented with blue edible berries and reddish-purple winter color. It likes full to partial sun, is deer resistant and attracts birds. This is a wonderful plant. Zones 4-7.
Rhododendron, size varies. With hundreds of varieties of this well-known plant available, just be aware that hardiness varies and be careful to purchase only specimens that are clearly labeled to be hardy to at least 15 degrees below zero for our area. Some readers may need even hardier varieties. Certain Rhodies are hardy down to -30. Most do best in partial sun and rich, moist soil. With their large trusses of colorful flowers, they are worth a little bit of extra care.
Kinnickinnick, 6”-1’ tall x 2-3’wide. A native also known as Bearberry, this plant boasts tiny pale pink bell shaped flowers in spring, persistent red berries and shiny evergreen leaves year round. Likes full to partial sun. Zones 2-6.
Creeping Phlox, 6” tall x 2-3’ wide. This unassuming mat of bright green needle-like leaves announces itself in spring by covering itself in star shaped flowers of blue, pink or white. If it gets a light shearing after the flowers fade, it will bloom again, but not with as much gusto. If not shorn, it will still look fine. They’re very nice draping over low walls, in rock gardens or as edging. Zones 3-8.
There are many additional worthy evergreen plants to profile, but space doesn’t allow. If I omitted a favorite of yours, let me know by commenting below, e-mailing me at firstname.lastname@example.org, writing on our Facebook wall or on Twitter (see hyperlinks for Facebook and Twitter below). I can include it in a future article! Evergreens are an important element of any landscape. I hope you are inspired to add some to your garden. Thanks so much for following The Winter Landscape series. I’ve thoroughly enjoyed writing this series to help add some colorful and creative ideas for intercepting the drabness of Winter. Most everyday we post all things plants, landscaping and just plain fun, on our Facebook page, and I would encourage you to stop by and give us a “Like”. We are also on Twitter, if that’s your cup of tea.
Next time: The Beauty of Dormant Trees.