Evergreens are great for the winter landscape
By John Zvirovski/Sun Garden Editor
What would the winters be like without the wonderful sight of evergreens? They are that ever important part of the landscape that seems to show life even during the bitter cold of the season. But what is it about the evergreens that make them so unique from the rest?
One of the most common evergreens we see in our landscapes is the Colorado blue spruce. It seems to dominate most yards as the evergreen of choice, but we could see potential problems if it continues to be our evergreen of choice.
Many needle diseases are now occurring that attack this tree in our area, causing browning and needles to drop over a period of a few years. Once it has taken control, the tree will perish. If this problem persists, many of the evergreens will disappear, and we will be left with a dull landscape in our snowy months.
Just in the past ten years came the introduction of needle cast in our area, which is a fungal disease that attacks the blue spruce. It causes premature death in the needles and eventually in the tree itself. It is more pervasive in warm, wet weather than in other conditions. This fungus was on the decline but has made a serious reappearance in the last couple of years. It is because of a disease such as this, why we need to consider additional diversity in our evergreen choices.
Many varieties exist over the common blue spruce trees. There is the Black Hills spruce that has shorter, dense needles and has a deep green coloring. It is a tall and narrow type that is considered to be one of the fastest growing of the spruce selections. Norway spruce has a deep, green coloring and resembles the blue spruce, however it is showing resistance to many of the needle diseases and are not used nearly enough in our area.
There are also ornamental dwarf varieties that don’t take nearly the amount of space as the large ones, such as the Montgomery blue spruce that grows up to 8 feet high. There is also the bird’s nest spruce that only grows 3 to 5 feet high and about 8 feet wide. The dwarf Alberta spruce is very tight and compact and rarely exceeds 5 feet in height by 3 feet in width.
Over the spruce varieties, there are many pines that are also available. Pines have a more airy structure that allows more light to fall through their canopy. The grass tends to grow better under this selection due to the light shade beneath them. Like the spruce trees, pines still have that wonderful evergreen coloring, a great scent and a nice pyramidal structure in its formative years. In the mature stages, pines tend to lose that pyramidal structure and become flat on top and broad. Many tend to lose their lower limbs and expose a wonderfully textured bark along its trunk. Since some people choose to cut the limbs off their spruces in the landscape to mow under them anyways, this would be a better selection for the gardener who does less maintenance.
Of the pines, the Scotch, ponderosa and Austrian are the best varieties for the area. They tend to handle more of the alkaline conditions that exist in our region. The red, white and Jack pines tend to prefer an acid based soil that would exist in areas such as northern Minnesota and tend to suffer more in our soils. The Scotch pine has needles about 2 to 3 inches in length and the bark is a beautiful copper color. The ponderosa and Austrian pines have needles 5 to 6 inches in length and develop large pinecones, which drop to the ground annually. Kids have a great deal of fun collecting these items and they are also great for the holiday seasons.
Another unique variety is that of the American or European larch. It is the one “evergreen” that has a light lime green color in the summer, a brilliant yellow in the fall and drops all of its needles in the winter. It has been called the deciduous evergreen, but it adds a wonderful texture to the landscape in all seasons.
Other evergreens come in the form of junipers, cedars and arborvitaes. The junipers can grow to be a large 20- to 40-foot tree, like the Rocky Mountain juniper, all the way down to the small blue rug juniper that only gets about 2 to 4 inches high and spreads to about 8 feet. Smaller junipers that range in the area from 2 to 5 feet would be items such as the Andorra juniper with its red coloring in winter and green coloring in summer, the savin juniper with its upright branching to the welch juniper, which has wonderful blue coloring in its needles.
One of the newer varieties of an upright juniper comes in the form of the sky rocket juniper. It should reach a height of 12 to 15 feet with no more than a 3-foot spread. It is has a hardiness zone of four, and it seems to be hardy enough for our area. It is great for those areas where you don’t have much room but want something tall and slender.
The arborvitaes are a group all in themselves, as they do not necessarily have needles as much as they have scale-like leaves. The branching is flat and not prickly, rather almost soft to the touch. They maintain a nice deep, green color throughout the year and can come in very short, round forms like the hetz midget, which only gets 2 1/2 feet tall by 2 1/2 feet wide. These are known as the globe arborvitaes. The common globe selection can become 6 to 7 feet around and requires more growing room. They also come in a nice tall and slender selection, such as the emerald green arborvitae or degroot’s spire, which matures to around 15 feet tall and has a width of about 3 to 4 feet. Some of the older varieties such as the techny arborvitae have an airier appearance and can be as wide as 8 feet after maturing. The slender ones are becoming more common for people with limited space.
There are other evergreens that stay under 5 feet tall such as the gold thread chamaecyparis, the blue star juniper and the Andorra juniper that show colors of blue, yellow and red throughout various times of the season.
As you can see, there are many selections of the evergreen species that can be chosen for use in the home over the common Colorado blue spruce. With a mix of many different varieties in your landscape, you can create quite a showcase both in the summer and during the winter seasons. It is time to start diversifying our landscapes with the many selections on the market and begin to create a more interesting and appealing environment in which we live. Ahhh variety, it really, truly is the spice of life!