Freelance
PLANTING YOUR FUTURE
As summer has run its course, I’ve had my eye on the growth patterns of all our various paloverde. When customers want information about plants, I try to make sure that personal observation backs up everything that written accounts provide.
The Desert Museum Palo Verde has been around since 1981, but it took most of the following decade for nurserymen to produce enough of them to make them readily available to the general public.
We owe our thanks for this beautiful tree, to the great observation skills and the desire to make a “better tree” to Mark Dimmitt of the Arizona-Sonora Desert Museum. As early as the 1970s Dimmitt was evaluating the characteristics of Blue Palo Verde (Parkinsonia floridum) and observed that there were some of them that had features that appeared to be more typical of the Foothills Palo Verde (Parkinsonia microphyllum) and the Mexican Palo Verde (Parkinsonia aculeata). So he started the arduous task of collecting and germinating seeds from these special trees. Over the next 10 years he was able to isolate a superior seedling that included the genetic composition of all of the three types of paloverdes. From the Mexican Palo Verde the tree received the genetics for strong upright growth and large bright flowers. From the Blue Palo Verde came small delicate leaves while the Foothills Palo Verde may have contributed to its sturdy character and cold hardiness.
So this “better tree” really has some remarkable characteristics and possibly the best is that it is absolutely thornless.
The Desert Museum Palo Verde can handle temperatures as low as 15 degrees Fahrenheit and shows extremely rapid growth throughout warm weather. The flowers, which are larger and brighter than any of its predecessors, can start as early as March and continue in abundance through May. There are intermittent blooms during the summer and fall. The tree exhibits strong upright growth with vigorous branching which serves to provide a more complete shade than other species.
Now that the Desert Museum Palo Verde has become plentiful and there are many that we can observe, both in the ground and in the nursery, it is obvious that the hard work that Dimmitt put into producing this tree of convoluted genetic composition has paid off. It is, indeed, “better”! We are observing growth rates of 5 to 6 feet a year in the ground and at least 4 feet a year in a container.
They respond very well to light pruning and shaping during the growing season. Planted this time of year will give several months of growing season, and as we cool down in the fall, the roots will continue growing. Next spring the tree would be well prepared for some major leaps of growth. Observations agree with the written record – the Desert Museum Palo Verde is, indeed, a fast-growing, exceptional tree.
Cathy Bishop, co-owner of Mesquite Valley Growers Nursery, has more than 30 years of gardening experience. E-mail her at weekendplus@tucsoncitizen.com.