When I began advising people about potentially suitable plants for their landscapes some 30 years ago, a large tree meant one that could become a statuesque 60 or 80 feet tall over time.
Today’s smaller lots have shrunken what is considered to be a large tree, or a medium or small tree for that matter, to the point of miniature proportions.
Most trees needed to define, shade or add dimension to patios in the smaller landscapes constantly challenge us to find plants that have been overlooked and put them to use in new ways.
Two plants I have always thought to be totally underused are acacias from our own desert. The biggest reason that these plants have been overlooked is that all of our desert plants are armed with thorns. On these two, the thorns are fairly small, and not a bit unreasonable to work with.
The two plants I am talking about are Acacia greggii, or catclaw acacia, and Acacia constricta, or whitethorn acacia. Both are on virtually every homeowners association’s list of acceptable plants, and I truly think their underuse has a lot to do with the fact that people have a difficult time thinking what these will become as they mature.
Catclaw acacia (its common name is derived from the shape of the thorns) is the larger of the two. Though it is slow-growing, one will find that growth rate almost a necessity for a plant small in mature stature, because plants don’t grow rapidly to a mature size and stop – it is an ongoing process.
The fragrance of these plants’ flowers alone is enough to recommend them. As soon as we hit our first 100-degree day, they seem to burst into bloom. And while the blooms are cream-colored and not particularly showy, the perfume they emit is the Sonoran desert’s crowning glory of fragrance – light, but incredibly sweet; heady and lingering; profuse both day and night.
The plant itself can be gorgeous. It is best when gently trained into a multitrunk tree and its natural form easily leads to that. As it ages, it becomes gnarly and ancient-looking. Use this small tree in a place where you want lacy shade in the summer and the warmth of the sun in winter. It can be kept easily at 8 feet or developed beautifully to 18 feet and it is hardy to zero degrees.
Whitethorn acacia is slightly smaller and blooms emerge two or three weeks later in the early summer. While out of leaf, the branches have a reddish glow that is attractive in its own right. When it leafs out, it is bright green.
Already many of the other plants’ leaves are looking dull and dusty, and here comes the whitethorn acacia, fresh with its bright new leaves. This is followed by its flower show: bright golden balls in profusion, fragrant, though not so much as the catclaw cousin. A bit smaller, it still has a twisting, gorgeous multi-trunk potential of from 6 to 12 feet and is hardy to 5 or 10 degrees.
Cathy Bishop, co-owner of Mesquite Valley Growers Nursery, has more than 30 years of gardening experience. E-mail her at firstname.lastname@example.org.