   Coniferous Trees for the Verde Valley - August 24, 2005 Jeff Schalau, County Director, Associate Agent, Agriculture & Natural Resources Arizona Cooperative Extension, Yavapai County Coniferous trees are resinous evergreens that bear their seeds in cones rather than true flowers. A conifer is also called a “gymnosperm” meaning naked seed. Examples are pine, fir, juniper, cedar, cypress, larch, and tamarack. Several conifers are suitable for planting in the Verde Valley area and fall is the best season to plant them. They can be planted as specimen trees for accent/interest or used as a privacy screen or windbreak. Remember that some of these trees are very large and may be unsuitable for small residential settings. However, many compact and pendulous cultivars are available and better suited to small spaces. They are also very resinous and should not be planted close to your home or other flammable structures. Arizona Cypress (Cupressus arizonica) is the only native cypress in the southwest. It is a large tree (40 ft tall/25 ft wide) with gray-green, scale-like foliage and will require irrigation during dry periods to avoid cypress bark beetle damage. The variety 'Glabra' has smooth, red bark that exfoliates every year. Leyland Cypress (Cupressocyparis leylandii) is a hybrid between Alaska yellow cedar and Monterey cypress. It is very fast-growing to 40 ft tall/20 ft wide and has green, scale-like leaves. Often planted as a privacy screen and also very susceptible to cypress bark beetles if not irrigated during dry periods. Elderica Pine (Pinus elderica) can grow to 40 ft tall/20 ft wide if grown in a protected area or a dense stand. It is an excellent pine for Cottonwood, Camp Verde, and other areas of the Verde Valley that do not have extensive native oak populations. In the oak areas (such as Sedona), it can get Comandra Blister Rust which eventually kills the tree. It is also sold as Quetta pine, Goldwater pine, and Mondell pine. Japanese Black Pine (Pinus thunbergiana) has a spreading habit (20 ft tall/20 ft wide) in our climate and requires regular irrigation during the dry season. One of the few conifers that tolerates pruning and is suitable for planting in irrigated landscapes. Pinyon Pine (Pinus edulis or P. monophylla) is a well-adapted pine for the entire Verde Valley area. The single-leafed pinyon (P. monophylla) is the native species in our area. Both are very slow growing to 20 ft tall/15 ft wide. The seeds (pinyon nuts) are delicious if you can get them before the rodents and birds. Deodar Cedar (Cedrus deodara) is a large (80 ft high/40 ft wide), fast growing tree. In fact, it may be too large for many residential landscapes. Short, silvery-green needles are 1 ½ inches long and occur in rosettes. Graceful, pest resistant, and drought tolerant once established. They are widely planted in the Verde Valley and are distinguishable at a distance by their droopy tops. Atlas Cedar (Cedrus atlantica) is a smaller, more upright version of the Deodar cedar, but can grow to 50 ft high/30 ft wide. It is also drought tolerant and pest resistant. Blue Spruce (Picea pungens) can grow to 80 ft high/30 ft wide, but few specimens have been planted long enough to reach this size in our area. Blue-gray needles are sharp and about 1 inch long. The blue color is due to a waxy coating on the leaves. Spruces are susceptible to spider mites. I suspect that the Verde Valley is on the edge of their suitable planting range because I have seen several die for no apparent reason. Junipers (Juniperus spp.) are available in many cultivated varieties which can be difficult to distinguish. Like cypress, they have scale-like leaves. They tend to be very drought tolerant and come in a range of colors and growth forms. Hollywood juniper (J. chinensis ‘Torulosa’) is a small landscape tree with an interesting, twisted growth form. Eastern red cedar (J. virginiana) was widely planted in the past, but not as popular today. Native species include one-seed juniper (J. monosperma), Utah juniper (J. osteosperma), and alligator juniper (J. deppeana). The natives are sometimes available from native plant growers on a limited basis. The University of Arizona Cooperative Extension has publications and information on gardening and pest control. If you have other gardening questions, call the Master Gardener line in the Cottonwood office at 646-9113 ext. 14 or E-mail us at mgardener@verdeonline.com and be sure to include your address and phone number. Find past Backyard Gardener columns or submit column ideas at the Backyard Gardener web site: http://cals.arizona.edu/yavapai/anr/hort/byg/. |