We now know what to look for in shade trees. Here’s how to pick best ones for North Texas
I clicked on one of those rotating video things on Facebook the other day. It showed the wealthiest people in the world year by year for the past 25 years. I could watch the names rise and fall through the years. I’ve clicked on the same sort of thing for population growth of cities and countries and the like. I’m a sucker for statistics like that.
It got me to thinking about 50 years ago when I was working in a local county Extension office answering the phone eight hours a day every day of the week. As I still do for my radio programs, I kept a log of all the topics of each of those calls. One-third of them pertained to lawns, but shade trees were a strong second, and what crossed my mind was the trees people were asking about. It’s as if we have an entirely new cast of characters for this current act of our play.
New houses back in the 1970s were given two trees, one on each side of the front walk. I’m talking about average houses that young marrieds like my wife and I could afford. The list of trees from which builders chose is horrifying by today’s standards. It included Siberian elms (known more commonly then as “Chinese” elms), silver maples, fruitless mulberries, and Arizona ashes.
Gardeners back then worried more about speed of growth than they did about longevity. They wanted to know how many years it would be until their trees would be providing shade, and those were trees that could provide cooling shade the fastest.
And, as if that list wasn’t frightening enough, we added more trees to our plantings: mimosas, cottonwoods, weeping willows, catalpas and sycamores.
What most homeowners didn’t realize back then was that every one of those trees has one or more fatal flaws. Sure, they all grow rapidly, but they’re all weak-wooded, messy, and subject to serious insect and disease problems. They all die short and hard lives, and they’re not pretty as they make themselves ready for composting. Often, there’s a great deal of expense in having them removed before they come crashing down.
We’ve learned a lot in those 50 years. We know to choose for quality, not just for speed. We look for trees that are adapted to our soils and our climate, and we seek types that are reasonably free of serious insect and disease problems. And we’ve learned that Bradford pears and their sisters are dreadfully weak-wooded — that almost all of them break into pieces within their first 15 to 20 years. Some cities and even states now ban them entirely.
For the past 30 years I’ve boiled my list of recommended large shade trees for North Central Texas down to seven: live oak, Shumard red oak, Chinquapin oak, bur oak, pecan, cedar elm and Chinese pistachio.
Additionally, for evergreens I suggest our native eastern red cedar juniper. Southern magnolias are great if you don’t mind a tree that is admittedly slower growing than the others, and there are several selections of it in varying mature heights.
If you need a mid-sized shade tree, Little Gem southern magnolia would be the very best. Ginkgoes, redbuds, golden raintrees, and Mexican plums are other fine choices. Most of those are plants that were essentially unused in the 1970s in North Texas.
Another great example of how far we’ve come: crape myrtles. In the 1970s you went to the garden center and asked for your crape myrtle only by color. It was a very rare day when you got a plant with a variety name on its tag. It was “red,” “pink,” “purple,” or “white.” Odds were very good that it had been grown in a field, then dug, balled-and-burlapped in the winter, and then either put into a container or just sold to us B&B. You hoped you had a healthy plant of a good type. Frankly, even pros in the business, me included, had no idea how many varieties there were. (That number is actually somewhere around 150.)
Today, it’s almost unheard of that a nursery would try to peddle a crape myrtle solely by color. We want to know its specific variety, and in finding that out we can determine its expected color and mature height and width. It’s made using crape myrtles in landscapes so much more rewarding.
Even with all these advances, however, I can still think of improvements we need to make. HOAs and city tree ordinances, for example, are well meaning, but they have some notable shortcomings. It’s been my observation that many of them still require two trees in every front yard. Our son lives on a cul-de-sac, so his front yard is very small. Still, the HOA insisted on two live oaks in that front yard. Unfortunately, live oaks have wing spans of 75 feet, so they would have been totally impractical shade trees for his landscape.
In another place in our city a permit was given to plant live oaks in a parkway (between the sidewalk and the curb) 6 feet from a busy roadway and directly beneath the neighborhood’s power lines. Obviously, the trees have been flat-sided, topped, and otherwise mangled. Trees that get planted in parkways often develop massive surface root systems that crack curbs, walks, and streets.
Cities’ tree ordinances should take into account merchants’ need to be visible to drivers passing by on neighboring streets. It’s fine to require trees be planted in parking lots, but they should be arranged so that disfiguring pruning to remove all the plants’ lower branches won’t be required a few years down the road. That kind of butchery is a blight on the cityscape.
All of which is to say, we’ve come a long way in the past 50 years, but we have a long way yet to come. Let’s show our beautiful shade trees a little more love.