What would winters be without the marvelous view of evergreens? They are that ever important part of the landscape that seems to show life even during the freezing cold of the season. But what about the evergreens that make them so unique from the rest?
Colorado blue spruce is one of the most common evergreens we see in our landscapes. It seems to dominate most yards as an evergreen choice, but we could see potential issues if it continues to to be our evergreen choice. Many needle diseases are occurring now that attack this tree in our area causing the needles to turn brown and drop over a period of a few years. Once he takes control, the tree will perish. If this problem persists, many conifers will disappear and we will be left with a dull landscape during our snowy months.
In the past 10 years, the introduction of needle melt in our area is a fungal disease attacking blue spruce. It causes the premature death of the needles and eventually of the tree itself. It is more prevalent in hot, humid weather than in other conditions. This fungus was in decline but has made a serious resurgence over the past two years. It’s a disease like this in which we need to consider additional diversity in our evergreen choices.
Many varieties exist on common blue spruces. There is Black Hills spruce which has shorter, dense needles and is dark green in colour. It is a tall, narrow type that is considered one of the fastest growing spruce selections. Norway spruce has a dark green color and resembles blue spruce, however, it shows resistance to many needle diseases and is not widely used in our area. There are also ornamental dwarf varieties that don’t take up as much space as tall ones, such as the blue Montgomery spruce that reaches 8 feet in height. There is also the Bird’s Nest Spruce which is only 3 to 5 feet tall and about 8 feet wide. Dwarf Alberta spruces are very tight and compact and rarely exceed 5 feet in height by 3 feet in width.
Above the spruce varieties, there are many pines that are also available. Pines have a more airy structure and allow more light to pass through their canopy. Grass tends to grow best under this selection due to the light shade below. Like spruces, pines still have the wonderful evergreen coloring, good fragrance and beautiful pyramidal structure in its formative years. At their mature stage, pines tend to lose this pyramidal structure and become flat on top and wide. Many tend to lose their lower limbs and expose wonderfully textured bark along their trunks. Since some people choose to cut the branches off their spruce trees in the landscape to mow them anyway, this would be a better selection for that lower maintenance gardener.
Among the pines, Scotch, Ponderosa and Austrian are the best varieties in the region. They tend to handle more of the alkaline conditions that exist in our area. Red, white, and jack pines tend to prefer acid-based soil that would exist in areas such as northern Minnesota and tend to suffer more in our soils. Scots pine has needles about 2 to 3 inches in length and the bark is a nice copper color. Ponderosa and Austrian pines have needles 5 to 6 inches in length and develop large cones, which drop to the ground each year. Kids have a lot of fun collecting these items and they are great for the holiday seasons too.
Another unique variety is that of American or European larch. It is the only “evergreen” that is a light lime green color in the summer, a brilliant yellow in the fall, and drops all its needles in the winter. It has been called the deciduous evergreen, but it adds wonderful texture to the landscape in all seasons.
Other conifers come in the form of junipers, cedars, and arborvitaes. Junipers can grow from a 20 to 40 foot tree like the Rocky Mountain juniper to the little blue juniper which is only about 2 to 4 inches tall and spreads up to 8 feet. The smaller junipers that vary in the area of 2 to 5 feet would be items such as the Andorran juniper with its red coloring in winter and its green coloring in summer, the Savin juniper with its vertical branching to the Welch juniper, which has a marvelous blue coloring in its needles.
One of the new varieties of upright juniper comes in the form of Sky Rocket Juniper. It is supposed to reach a height of 12 to 15 feet with no more than a 3 foot spread. It has a hardiness zone of 4, and it seems to be quite hardy for our area – great for areas where you don’t have a lot of room, but want something tall and slim.
Arborvitaes are a group in their own right, as they don’t necessarily have as many needles as scale-like leaves. Their branching is flat and not prickly, rather almost soft to the touch. They maintain a beautiful dark green color throughout the year and can come in very short, round shapes like the Hetz Midget, which is only 2 1/2 feet tall by 2 1/2 feet wide. These are known as globe arborvitaes. The common globe selection can grow 7 to 7 feet around and requires more growing space. They also come in a nice tall, slender selection, like the Emerald Green Arborvitae or Degroot’s Spire, which matures around 15 feet tall and is about 3 to 4 feet wide. Some of the older varieties such as Techny Arborvitae have a more airy appearance and can be up to 8 feet wide when mature. Thinner ones are becoming more common for people with limited space.
There are other conifers that are less than 5 feet tall, such as Chamaecyparis Gold Thread, Blue Star Juniper, and Andorran Juniper which exhibit colors of blue, yellow, and red at different times of the season.
As you can see, there are many selections of evergreen species that can be chosen for home use over the common Colorado blue spruce. With a mix of many different varieties in your landscape, you can create quite a showcase in both summer and winter seasons. It’s time to start diversifying our landscapes with the many selections on the market and start creating a more interesting and attractive environment in which we live. Ahhh variety is really, really the spice of life!