Publications (Paul's Blog)

August 24, 2009

LOCATION, LOCATION, LOCATION

Filed under: Uncategorized — Paul Dowlearn @ 1:19 pm

With the movement towards using native plant material in the home landscape growing by leaps and bounds each year it is high time that we clear up a few general misconceptions. One of the main attractions to the use of local natives is they are just plain easier to grow. If we can find some local plants that we like the looks of then we have a truly winning combination. Right?……Well, almost. Read on.

To begin with we need to acknowledge the sheer size of the state we live in. Ecologically speaking Texas encompasses several climates from the seriously cold and windy Panhandle to the subtropical Valley or from the damp forests of East Texas to the dry desert of West Texas. As far as botany is concerned, Texas is divided into ten distinctly different eco regions according to the types of plants that dominate each region. Where these divisions meet we can observe a gradual blending of plant species or a sharp contrast as one encounters when dropping off the Balcones Escarpment onto the Coastal Plains. Notice in the first paragraph I used the term “local natives.”

Before you go shopping you need to maybe check a map to determine which of these eco regions you live in (go to npsot.org for a map). It is popular right now for nurseries to inform the shopper that certain plants are Texas natives. That is no insurance that this particular native will work well for you. Knowing which part of the state that plant is native to is the real criteria. That information is readily available by asking a knowledgeable person, consulting a good reference book, or doing a web search.

Another fairly reliable method to determine which native plants are suited to your particular area is to simply draw a 50 mile, then a 100 mile radius around your location. Within the 50 mile circle it is a pretty safe bet that there is little difference in climate. The natives found within that radius will at least be capable of handling the weather. Beyond the 100 mile circle it is likely that there will be some difference in temperature, humidity, and rainfall. Note that this method will not work in areas where drastic changes in elevation occur such as in the mountainous regions of West Texas or the canyon country of the Panhandle. In these situations elevation will play a more significant role than actual distance.

Now if you are not confused yet, let’s take it a step further. Within each of these eco regions we find wet places in low areas or near creeks, rivers, lakes, and etc. Dry areas on higher ground. Shady places in wooded areas or the northern exposure of hills. Sunny places in clearings and open grasslands. Extremely hot exposures in rocky or gravelly soils facing south or west. Add to this the full gamut of soil types from tight clays to loose sand and from high fertility to very poor soil and you get an amazing amount of diversity in what we call microclimate. Observe the locations where your desired plant wants to grow in the wild. Quite a few plants found growing in these microclimates are pretty finicky about being planted outside their preferred habitat. For this reason, you may fail at growing certain plants even though they are native to your local area.

Let’s use blackfoot daisy (melampodium leucanthum) as an example. This beautiful little white flowered daisy can be found growing over a much of the state. It can set off a profuse bloom any time during the spring, summer, or fall. It is very drought tolerant, cold hardy, and it thrives in reflected heat. Seems like an easy plant to grow until you pay attention to microclimate. In Nature, blackfoot daisy is almost always found growing on very exposed rocky or gravelly hillsides. If you take this plant and attempt to grow it in rich garden soils that are constantly irrigated it will probably not live very long. On the other hand if you plant it in a sunny well drained raised bed, berm, or rock garden and neglect it some it may thrive for many years.

011_14Now let’s look at our Texas bluebell (eustoma grandiflora) as a second example. This is one of the showiest of our native wildflowers. Texas bluebell usually does not bloom until the serious heat of late June to early July. Once it has begun it will continue to bloom throughout the summer and into the fall.
Several years ago I noticed large numbers of these big flowered beauties growing around the shoreline of a local lake. They all were found slightly away from shore (not actually in the water) and out to about 25 feet or so away from the shore where they suddenly stopped as if a line had been drawn to prevent further spread. As I sat and scratched my head over this I finally deduced that the water itself was the limiting factor. On a windy day, the breaking waves would be blowing spray about 20 to 30 feet up the bank giving the bluebells an extra drink. With this in mind I began noticing that almost without exception bluebells are found growing in low places and often in poorly drained soils. This makes perfect sense for a summer bloomer to prefer places that puddle up after a quick summer shower. Texas bluebell is a perfect candidate for that deep moist garden soil where the blackfoot daisy would surely rot.

Then there are those plants that are very forgiving. They thrive in a wide range of soils and conditions. This past year I was working with a client who had spent most of his career in Nebraska. He wanted me to take a look at a native plant display from the University of Nebraska as an example of what he wanted to recreate here in Wichita Falls. I was not overly thrilled by this but I went ahead and looked up the web site. At first I was taken aback by all the plants listed (about 70% to 80%) that were native that far north and were also native to our local area. Then I remembered that both Nebraska and my portion of North Texas were on the Great Plains. We share very similar growing conditions although Nebraska gets much colder in the winter. The same plants that are in peak bloom typically in May here in North Texas would bloom in June or July for the folks in Nebraska. That was the only real difference.

A good example of one of these forgiving plants is turk’s cap (malvaviscus arboreus var. drummondii). This long lived perennial produces bright red whorled flowers similar to a turban, hence the name. Normally associated with wet places, turk’s cap is also very drought tolerant. It can stand full sun or full shade as well making it one of those one-size-fits-all plants that the nursery industry just loves to sell. Turk’s cap is native to much of Texas excluding the West Texas deserts and the Panhandle. If we were to locate some wild turk’s cap here in North Texas we would probably be looking at a rather tidy plant no more than three or four feet tall and wide.Copy (4) of 014_14 If we travel down into the Hill Country we would find the same plant to be five or six feet tall and possibly more with a semi-woody base. Then if we were to travel even further south into the tropical regions of Mexico we would find turk’s cap to be a tree with a woody trunk. Here is a plant that has adapted itself over a wide range of different climates. If it were not for winter and our typically dry summer then turk’s cap would certainly be a tree in North Texas as well.

The point to all this is simply not to assume that just because a plant is called a Texas native in the nursery trade means that it is bulletproof, never needs water, or improved soils. Any time we take a plant away from its preferred habitat it will be stressful to that plant and it doesn’t really matter whether the plant is from a different part of Texas or from China. The gardener must create the right conditions to relieve that stress as much as they possibly can. If you have failed at growing a certain plant but you really want to have that plant then you must study the microclimate carefully. Find out where it thrives in Nature then try again by creating similar conditions. The more you know, the easier it is to grow.

Until recently, most of the plants we bought and sold in the traditional nursery trade were the forgiving one-size-fits-all type that would grow in a wide range of soils and climate. Water was cheap and extra inputs were a given. Today more people are demanding less water use and lower maintenance in the landscape. Native plants and native plant nurseries have come to the market place to play a key role in fulfilling this need. This does not mean that gardeners no longer have to study horticulture. Indeed, we have been given a whole new set of tools that compel us to study even more. The ease of creating an aesthetically pleasing landscape that does not demand input from outside resources has been increased dramatically as long as we pay attention to location.

Therefore we should not attempt to grow West Texas desert plants in our eastern forests or vice versa. Instead we should take pride in the particular eco region that makes our part of the state what it is. We should display those plants in the bulk of our attempts at ornamental landscaping. Certainly we should continue to experiment with our native plants to discover just how adaptable they may be but we should always keep in mind that we are experimenting. Experiments often fail. Check the environment that the plant is found in Nature and you will have a better chance at success.
-Paul Dowlearn

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