If you are looking for some unusual plants to spice your yard, this is for you. There are many trees and shrubs brought into the country from other areas that are perfectly hardy and extremely interesting. The difficult part may be finding them. "Exotics" is my loose term for imported and unfamiliar American species.
There are many great fir tree varieties and they should be used more than they presently are in providing screens or as focal trees. Concolor, or White Fir, (Abies concolor) is a western native. It can have 2" long green to blue needles and stay branched to the ground. White Fir has a soft appearance and stands out among other needled evergreens. It can grow to 60' high and 30' wide in rich, moist, well-drained soil, but tolerates dry, poor soil once established. Sun gives it the best chance to be full; yet, it will grow in light shade. At about 5', one to two feet of growth is common.
Korean Fir (Abies koreana) was introduced in the early 1900's from Korea. Although not tested in Zone 4 extensively, it has done well in dry and wet areas, in wind and sheltered spots, although growing only about 6" a year. It has the potential to reach 50' by 20' wide. The branching is loose and more open than many firs. The foliage is a unique light green with silver undersides, with stiff needles openly spaced around the branch. "Horstmann's Silberlocke" is a denser needled form, which looks like someone spray-painted white on the outer surface of the needles.
Corkbark Fir (Abies lasiocarpa), also known as Rocky Mountain or Alpine Fir, is a true Charlie Brown tree in the first ten years. It grows slowly and quite openly branched. Yet, with some trimming and fertilizing, this silver gray fir is well worth planting. As it ages, it fills in and looks similar to Colorado Spruce in color and form. Variety arizonica does well in Maine and its bark eventually gets creamy white and corklike. It has done well in rich loam, both sheltered and windy spots. However, Corkbark Fir should tolerate dry soil.
Nordman Fir (Abies nordmanniana) is native to the Caucasus and Asia Minor. It is hardy in Maine, but can winter burn in a tough season. Although slow to get started, like many evergreens, it can grow a foot or more a year and reach 60' tall and 25' wide. Specimens in the wild have grown to over 100' overseas. This is truly one of the best specimen firs, with its dark, glossy, black-green foliage and thick, flat needles. Like other firs, rich, well-drained moist soil is best, but once established, they tolerate poorer soils.
Is anyone tired of seeing Colorado Spruce? Don't get me wrong. They can be a fine choice for certain spots. They are, however, susceptible to many insects and diseases that other spruce varieties are less prone to getting. Meyer Spruce ( Picea meyeri) has much the same growth habit and color, yet seems more soil tolerant and less susceptible to pests than the Colorado Spruce. This Asia import deserves wider use.
Norway Spruce (Picea abies) is equal to White Pine in growth rate and eventual size. Keeping low branches, it is a great screen or a very fine ornamental specimen. With arching, ascending branches and hanging needles, it appears to fit a Japanese garden, which belies its European origins. This tree tolerates dry or wet soil, sun or moderate shade, and high wind and salt. Norway Spruce will overpower a small yard, so give it plenty of space.
Serbian Spruce (Picea omorika) is a southeastern European introduction that grows moderately to 60' tall and 20' wide. It is very graceful and full, having dark green needles with white undersides. New growth can be lighter green to yellowish, giving it a tricolor effect. Serbian Spruce does will in moist soil and moderate shade, but can prosper in full sun under dry conditions. Strong windy sites should be avoided. Like White Pine, this spruce appears susceptible to weevil, which is its only drawback.
Oriental Spruce (Picea orientalis) was introduced from Asia Minor. This species has very short, tight needles on horizontal branches. There can be variations in habit, from open to dense, but it slowly will achieve 50' tall and 25' wide. The dark green foliage is similar to the better Serbian Spruces. Harsh winds should be avoided, yet this species will prosper in dry soil.
There are many shrub cultivars of the above spruces, with varying growth
habits and shapes. Explore your favorite nurseries for those suitable
for a chosen location. Variety is the cinnamon of life. Don't let the
term "exotic" or non-native steer you away from some very
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