Publications (Paul's Blog)

November 19, 2009

IS IT ANY WONDER?

Filed under: Uncategorized — Paul Dowlearn @ 10:54 pm

Any person who has attempted gardening has thought about why the plants we spend our time and money on often die. Conversely we are amazed at how persistent weeds are. Most often we blame our soils and weather conditions. While these do have a great bearing on what we can grow, one of the most important factors often goes without consideration. That is the bulk of plants we consider for home landscaping are exotic imports or man made hybrids (usually both) while the weeds we wish to do away with are usually natives. Is it any wonder we continually have problems?
Native plants have the advantage of having lived in your local area for many years. As successive generations grow they fine tune themselves to the local soils and weather patterns. The last major climate change was the great Ice Age which occurred some ten thousand years ago. Most of the native plants we see today have evolved with our changing climate since that time. Some were present native1 even before the last Ice Age while a few date back in time to that very ancient age, the Carboniferous Era. During that era there were only plants inhabiting the land masses of Earth. Considering this you can easily surmise that your local natives clearly have the jump on almost any plant we can import or attempt to improve upon by plant breeding. The plants we call weeds are also particularly well suited to growing in disturbed soils……..like our gardens.
If you visit a garden center in Amarillo you will pretty much find the same kind of plant material for sale that you would find in Dallas. Yet the residents of the High Plains will be quick to relate how different their growing conditions are from the Cross Timbers or Grand Prairie of the Dallas-Ft. Worth Metroplex. Still the home landscapes look very similar. This is due to the fact that the horticulture industry has always favored one-size-fits-all plant material that can be grown under a wide range of conditions. These plants are often referred to as “well adapted.” Bear in mind that what this really means is that the plants can be expected to survive given “normal” conditions plus some extra water and chemical support. More often than not, you will find your particular set of conditions a bit too cold, or too hot, or too windy, to dry, to wet, or the soil too compacted, rocky, or sandy, to suit your favorite hybrid. Only your local natives are perfectly adapted.
Lawn grasses are a good example. Even though Texas is a place where grasses are abundant, the two most commonly used are St. Augustine (from Asia) and Bermuda
(from Africa). These two grasses have been thoroughly researched, hybridized, and selected to give the home owner what they desire. These grasses have been tinkered with so much that the better varieties are now sterile (no viable seed production) and available only as sod. St. Augustine has always been a poor choice for those living north of Interstate 20 due to winter kill. Bermuda has done well over much of the state, so much so that it has become invasive and is one of the worst weeds imaginable when it comes to keeping it out of areas where we want to grow other plants. Both of these lawn grasses require lots of water, fertilizer, and mowing to look good. Is it any wonder that we have problems with weeds, insects, and disease? When these grasses become stressed due to drought or extreme weather the door is open to all three problems.
The number one recommended grass for the western two thirds of Texas is our native buffalo grass yet very few people have a buffalo grass lawn. This is mainly because buffalo will not “take over” any of the more aggressive grasses. Making the switch does require diligent effort plus it is very difficult to keep your neighbor’s Bermuda from encroaching. Still I can’t help but think it would have been much wiser if our forefathers in the industry would have taken a closer look at our native grasses before investing in these higher maintenance imports. Perhaps their goals and priorities were much different in those days.
The same story holds true of nearly all of the other plants we find in the nursery industry today. Most of our popular evergreen and flowering shrubs trace their lineage back to Asia. Most of our culinary herbs that are now regaining popularity hail from the Mediterranean. Many of the more popular annual bedding plants are actually from the tropics. In fact, when we study the provenance of most traditional landscape plants we find that very few are natives of the United States, let alone Texas. Is it any wonder we find the shelves of most garden centers packed with pesticides, fungicides, and fertilizers? Do we really need all this stuff to grow plants? Not so, says Mother Nature as she provides locally adapted natives that do not require such things.
Perfect evidence of this is found in the example of trees. Most of the trees that you will find that have done well in your particular area are the local natives. While there have been a few imports and hybrids that will adapt, and even fewer (thankfully) that have jumped thenative2 fence to become invasive, the fact is that it is near impossible to create special conditions to accommodate something as large as a tree. We can create special conditions for a vegetable garden, flowering plants, and even shrubs, but trees need to be able to grow in your soils and climate with little or no help in order to reach maturity.
Botanically speaking, the state of Texas contains ten distinctly different plant zones or ecoregions. Nature has shown us the plants that will flourish in each of these regions. We should not be jealous of what gardeners can grow in other regions. Instead we should find suitable plants that do well where we live and forget the assumption that we can grow whatever we want with extra water and/or chemical support.
For years, the residents in my hometown of Wichita Falls have attempted to grow trees like magnolia, silver maple, and pines that are native to East Texas. As young trees they can be pampered and brought along but as they get older the hot dry summer plus lack of humidity usually take their toll. For every hundred trees planted maybe ten survive the first few seasons. Out of those that do, perhaps only one or two will live past twenty years. Still most nurseries (not ours) continue to stock these trees due to their popularity. The average citizen sees only the ones that survive and makes the wrong assumption. Unfortunately there are far too many examples like this and far too many gardeners who are held in high esteem because they manage to grow something well beyond it’s normal range. The mystique of the “green thumb” lives on. Is it any wonder we find ourselves tempted to follow suit?
Of course the answer to all this is to stick with natives and heirloom plants that have proven themselves over the years. Look in your older neighborhoods to discover the plants that have withstood the test of time. Look at new landscapes to see the diversity of local natives that are just now being offered by cutting edge nurseries and landscape professionals. If you come across something in a book or magazine that appears interesting, take a look around and see if you find it growing in your hometown. Chances are you are not the first person who wanted to grow that particular plant. Just because a plant is native to Texas or cold hardy to your particular hardiness zone does not mean it will work for you.
I shudder to think what could become of the genetic perfection found in our local natives now that many of them are becoming popular. Historically, plant breeders have been guilty of “breeding plants to death” in the effort to produce more desirable traits. This can easily be seen in the case of roses, lilies, crepe myrtles, and a good number of popular plant varieties. It has already begun to happen with some of our showier wildflowers like Texas bluebell, purple coneflower, and gaillardia. I can only hope that there are enough practical minded horticulturists out there to preserve the plants found in the wild. For more info on your local natives contact The Native Plant Society of Texas (npsot.org) and The Ladybird Johnson Wildflower Research Center (wildflower.org). Always look to Nature for the best in long term maintenance and livability.

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