By Ken Lain, the mountain gardener
Of late there have been some rumors, misconceptions, and downright lies presented to mountain gardeners, and you should be aware of them. The lowland deserts have a significant influence on mountain landscapes, and some of their desert evergreens will grow up here, but not many. Those that do often have glorious but very short lives because they can’t resist the rusts, scale, bark beetles, and other notorious mountain diseases.
Evergreens need to be very hardy to thrive in the mountains of Arizona. This list of hardy trees will survive with just one caveat: Each is prone to a slow death if overwatered. Drainage around the roots is vital and proper irrigation techniques are critical. There are links at the end of this article for mountain planting and for safe watering. This column is about the right plants in the right places.
Here is a list of the top 10 evergreen trees that stand up to mountain winds, winter cold, and resist the naturally occurring insects and diseases found at higher elevations.
Colorado Spruce – When customers don’t know the name of this tree they just refer to it as “The one that looks like a Christmas tree.” The very thick branches swoop horizontally forming a perfect broad pyramid. Considered drought hardy, this tree prefers dry, windy conditions.
- Con– Tree aphids like the taste of native ponderosas and of Colorado Spruces. They rarely do serious damage and are easily spotted in mid-spring as new growth elongates.
- Pro – Ancient specimens are living proof that this tree does well. Feed with aluminum sulfate to bring out the silver blue of this perfectly formed tree. Size: 24’H x 60’W
Austrian Pine – This long-needled evergreen often is mistaken for a young ponderosa pine although it is far more graceful. Whereas the ponderosa loses all its lower branches as it matures, the Austrian’s rich green needles seem to flow right to the ground for a balanced appearance. The dense, stout, pyramidal growth is uniform right to the crown. It is the hardiest of the ornamental pines without the bug issues that plague many native pines. It makes a most effective windbreak or privacy screen.
- Con – There aren’t many negatives other than that this is a fast-growing, big tree. It has been known to overpower walkways and eaves of a house when placed incorrectly in the yard.
- Pro – The fastest growing of all pines. Can quickly grow 18 inches a year, and even more when under the care of an attentive gardener. Size: 35’H x 20’W
Juniper – The mountains of Arizona are famous for their juniper forests. A large assortment of junipers here at Watters in colors ranging from bright greens, blues, and silver. Excellent when planted as windbreaks or to provide thick privacy, and hardy enough for harsh commercial settings and investment properties.
- Con – Spider mites sometimes transfer from native junipers into the landscape. Watch for spider webbing in mid summer and treat with Watters’ organic ‘Captain Jacks Dead Bug Brew’ as needed. Many folks suffer from juniper allergies. However, if you are irritated by junipers keep in mind that you are surrounded by thousands of acres of native junipers and one line of ornamental junipers cannot bear the full blame for your miseries!
- Pro – The toughest of all the evergreens with consistent growth over the season. So hardy they are the trees of choice for property investors and commercial property owners. Many can be hedged and sheared to perfection. Size: varies
Piñon Pine – A local native that is exceptionally hardy and drought tolerant, it is slow growing with a broad, rounded crown. Perfect for all natural landscapes it makes an attractive grouping on hillsides or berms with low-growing perennials. It can take a starring role as a striking specimen in a rock garden. New growth is blue to green with clusters of pinecones as the tree matures. Edible seeds from the cones are considered a delicacy, commonly known as pine nuts.
- Con – In early spring our native piñon is prone to scale that is easily treated. (The non-native Single Leaf Piñon Pine sold here at Watters is preferred for it’s larger pine nuts and its natural ability at fighting off scale.)
- Pro – Once established can grow completely on its own. A true native evergreen in the mountains, it is perfect for naturalizing the scars of construction. Size: 15’H x 10’W
Vanderwolf Pine – Take a close look and you will see that the top of each needle is blue with a green underside. This very stately pine is so soft that most homeowners literally hug these trees! It’s very unusual and distinctive shape is unique to mountain landscapes.
- Con – Very unreceptive to thick heavy clay soil and/or a gardener with a heavy hand on the hose. Don’t overwater this evergreen or you could lose it within the first few weeks of planting.
- Pro – The color is stunning. Requires little to no pruning. Size: 25’H x 12’W
Fat Albert Blue Spruce – Sporting a shape similar to that of the Colorado Spruce, Fat Albert doesn’t grow as tall, so it won’t “take over” more than its allotted space. A broad pyramidal shape with exceptional blue needles that present a consistent blue color.
- Con – I really can’t think of any cons for this tree! I did see grubs eat some roots of a Fat Albert this spring, but that is a very rare sight.
- Pro – Intense silver-blue needles adorn this tree. For those that love a Christmas tree shape but need a tree with a smaller footprint. Size: 25’H x 12’W
Dwarf Alberta Spruce – This slowest growing of the evergreens is the easiest to maintain. Its perfect cone shape displays dense green soft-to-the-touch needles. Although it often is used to make a formal statement in a garden, it
is excellent as a container plant or miniature Christmas tree.
- Con – Watch for spider mite webs that can form in June. Spider mites like the taste of an Alberta Spruce but are easily thwarted by using Watters’ ‘Captain Jack’s Dead Bug Brew’.
- Pro – A small format evergreen that needs little to no maintenance, but has that classic evergreen look and feel. Perfect for large containers framing the garage, accenting decks, and highlighting pots at the front door. Size: 8’H x 3’W
Arizona Cypress – This tree is a real celebrity in the local garden world. Many mistake it for a juniper in appearance, but this blue evergreen forms a golfball sized cone instead of juniper berries, making it less allergy inducing than a native juniper. Very fast growing and readily tolerates mountain soil, valley winds, and bitter winter cold.
- Con – Carefully watch the frequency of irrigation the first couple of years after planting. If you are going to kill this evergreen, it will be from overwatering it, not from under watering.
- Pro – This fast grower should be a serious consideration for dry, dusty properties exposed to the elements of mountain living. Deer and javelina resistant. Size: 20’H x 10’W
Deodar Cedar – This fast grower has a central leader with soft branches that sway gracefully in the wind. So large a tree that it fits only in the largest properties.
- Con – Such a fast grower it often overpowers the landscape. Soft branches can break from heavy snowfalls. Needs more regular feeding than other evergreens or it will become yellow and off-color.
- Pro – Fast growing and drought hardy are this tree’s claims to fame. Size: 50’H x 25’W
Black Hills Spruce – With the deepest green of any evergreen and a density that light dares not shine through, this spruce’s perfect cone-shaped symmetry stands out in any landscape. It’s so cold-hardy that it actually prefers being planting in mid-winter! Although the tree looks delicious, neither javelina nor deer like to nibble on this evergreen.
- Con: A painfully slow grower, but methodical in its development. Very sensitive to garden soils that do not drain properly.
- Pro: A very easy to grow pine with beautifully blue colored needles. Slow, methodical growth means little-to-no maintenance is needed throughout this tree’s long lifespan. Size: 35’H x 16’W
Norway Spruce – Spruces grow so well at local elevations that most will thrive in local landscapes. A dense tree that easily blocks out wind and neighbors, the Norway is ideal for use as a privacy barrier, windscreen, or even a traditional showpiece. Grows faster than other spruces, but with a bright Irish green needle.
- Con – Such a fast grower it can quickly outgrow the average yard. Staking the young tree is necessary to keep soft, fast growing leaders from bending in the wind.
- Pro – Takes the funneled wind, intense sun, and bad soil better than most other evergreens. Loves growing at mountain elevation. Size: 50’H x 25’W
BIG CAUTION – Evergreens are field grown until reaching mature size. This is why its good to know the origin of the trees you plan to buy. A field-grown evergreen must be root pruned as it grows or it will not transplant successfully in our dry mountain air. Not only do we here at Watters hand pick our trees from trusted sources, but we also walk the field looking for signs of a tree that had been root pruned through its maturity. We then field dig, wrap the roots in burlap, transplant it into a grower’s container, and continue to root it for another season.
It’s difficult to explain but this process makes a big difference. Do the hard work of shopping to learn what others are saying about evergreen trees bought from the company you are considering to supply your tree. When acquiring evergreen trees you should make the time to hand pick the specimens going into your yard. Once an evergreen tree stresses and becomes ugly, it rarely grows its way to beauty.
Planting & Delivery Service – Evergreens are unusually heavy, bulky, and can inflict bodily damage while being installed in a landscape. After planting a mature evergreen tree it’s possible to look like you’ve been in a cat fight, and the cat won! So consider the cost of having your nursery plant it for you as money well spent.
Of course, the larger the tree, the more work it is to install so the more it costs to plant. The average size tree that stands head high costs about $100, and includes the warranty, labor, and all the material to plant it right.
Until next week, I’ll be helping local gardeners looking for evergreen trees here at Watters.
Throughout the week Ken can be located at Watters Garden Center, 1815 W. Iron Springs Road in Prescott, or contacted through his website at WattersGardenCenter.com.