Conifers are mostly needle-leafed or scale-leafed, evergreen, cone-bearing trees that can be found growing throughout the world. Among the 550 species are: pine, fir, spruce, cypress, yew, hemlock, redwood, and juniper. Conifers evolved 300 million years ago and, as a group, are adapted to mostly dry and cool environments. They dominate northern forests, but could they also prosper in the desert?
In 1984, the Men’s Garden Club of Green Valley planted a small Arizona Cypress tree in front of East Social Center as a memorial to departed members. Since that time, it has grown into a 40-foot tall living monument. That may answer our question.
Arizona Cypress (Cupressus arizonica) has soft-textured, gray-green foliage with rough gray-brown bark. Found throughout Arizona, this native grows into a near-perfect pyramid shape without pruning. Maturing at 40 feet high, it will spread to 25 feet wide. Because of its size, Arizona Cypress may best fit at the edge of a large property. Its outstanding natural form and handsome bark make it especially effective as a focal point.
Extremely drought tolerant, adaptable to various soil types, and able to endure the desert’s summer heat, this is a resilient evergreen. Established Arizona Cypress do not require fertilizer and can survive on a monthly summer watering. Rely on rainfall during winter.
Aleppo Pines (Pinus halepensis) were widely planted by settlers in the West during the late 1800s. These Mediterranean natives are mentioned in the Bible and today are found in native forests from Portugal to North Africa and Israel. Aleppos are fast growing, easily adapt to poor desert sites, and prefer elevations from 1000 to 3000 feet.
Early Greek temples required Aleppo Pines planted nearby to be considered “complete.” Legend tells us that the trees were decorated each year with flowers and ribbons in honor of Christ. As Europeans continued this tradition, these pines may have been the first Christmas trees.
Massive Aleppos have light green needles with a billowing canopy. They are well adapted to aridity, heat, and alkaline soil. Maturing at 30 to 60 feet high with a 20 to 40 feet spread, they can create an impressive focal point where space allows. They are cold hardy down to 20 degrees Fahrenheit. Water established Aleppo Pines monthly in summer, every two months in winter. Be aware that their shallow roots can heave concrete if planted too close to structures.
Resin from all pine trees is antiseptic, diuretic, beneficial to the respiratory system, used externally for liniment, plasters, poultices, and inhalers. Litter from both fallen needles and seasonal cones can require cleanup. However, pine needles make great mulch for perennials and succulents in the garden.
The real value of conifers may be the shade they provide as part of the landscape … a significant benefit in the desert.
Mary Kidnocker is a University of Arizona Master Gardener who lives in the Green Valley area. Her articles are featured weekly.