Thursday, March 17, 2011

Crossing the Line...

Mexican Petunia (Ruellia brittoniana)
This last freeze really devastated my little landscape. Some things are starting to come back but I’ll have to re-plant in a lot of areas. So I have been thinking about my strategy. Should I go for unique, interesting plant materials OR should I stay with tried and true, low maintenance selections? A question I’m still pondering. But it’s that term “low maintenance” I want to discuss in this GG Blog post.

If you examine gardening trends these days, you’ll discover an ever-growing emphasis on low maintenance landscapes. I guess it has to do with the limited amount of time folks have for gardening, or in some cases the term is used in connection with reduced inputs (i.e. watering, spraying, fertilizing, etc.) all of which decrease impacts on the environment. 

When the term low maintenance is applied to a plant, it usually means it’s well adapted to the area and doesn’t require a lot of inputs to keep it alive in the landscape. Often times these well adapted, low maintenance plants tend to be somewhat aggressive in their growth habit. After all, that’s what we’re looking for in many ways – right? Something that grows well without much water, fertilizer or care/attention.

So my question is – when does a plant cross the line from being low maintenance to invasive?

Chinese Tallow
Sometimes these distinctions can be rather subtle. Bermuda grass for example. A rugged, drought tolerant turfgrass that I spend hours pulling from flower beds and other areas in the landscape. How about Mexican Petunia (Ruellia brittoniana) a really tough plant that flowers prolifically all summer long BUT freely re-seeds and is extremely difficult to keep from spreading to every area of the yard. And of course there are more recognized invasives like Chinese Tallow. I have one in my front yard that is tough as a boot – but experts say they are destroying the ecosystem by taking over native habitat areas. Needless to say, there are numerous other examples of plant materials that one minute are low-maintenance and then, cross some arbitrary line and BINGO they’re invasive.

The term invasive is a bit confusing as well. Some plants are weedy in one area of the county/state but make great landscape plants in other locations. Ecologists tend to apply the term invasive more broadly, potentially eliminating the use of some useful, low maintenance landscape plant materials. 

Although many plants are described as invasive, that does not necessarily mean they are legally banned from distrubution. In fact, here in Texas, there are very few plants that fall in to this category (Chinese Tallow, Saltcedar, Tropical Soda Apple, Kudzu). Here’s a link to the Texas Department of Agriculture’s full list, including many noxious weeds http://info.sos.state.tx.us/fids/200701978-1.html. Texas Parks and Wildlife also maintains a list of prohibited aquatic plant materials http://www.texasinvasives.org/plant_database/tpwd_results.php.  There is another group (TexasInvasives.org) that maintains a list of plant materials that are “suspected’ of causing invasive problems. But it should be noted that this list is for educational purposes ONLY and has NO regulatory application http://www.texasinvasives.org

So I guess the bottom line is that deciding if a plant is low maintenance or invasive is largely a judgment call that requires some basic plant info. Remember – it’s always a good idea to checkout how aggressively a plant will grow in our area BEFORE sticking it in the landscape. It can be a fine line between low-maintenance friend to aggressive nightmare.

Visit the Galveston  Gardening website for more information http://www.GalvestonGardening.com

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