On the Concept of Native Gardening, Part Two.

Part one can be found here.

In the last post of this series, we explored the wonderful world of native elements in a garden and yard.  Now we move on to things that we have introduced to this continent, which are otherwise known as exotic plants.  For today, we can stick to the relatively good stuff, and just leave it at exotic and not invasive, which we can take a look at Monday.

Exotic Plants.


The word can be deceptive.  While exotic can indeed refer to something really beautiful and stunning, it mostly just refers to things which are foreign to the native habitat in which they are now cultivated.  In many parts of North America, especially in urban and suburban areas, exotic plants account for at least a third of what you see, including invasives.  Many of the more functional plants, namely trees used for shelter, shade, and windbreaks, lawn grasses, and some crops have been imported from Europe.  What can we say?  We like bread made from wheat and beer made from hops and barley.  We like our wine to be made from various strains of Vitis Vinifera rather than the more robust tasting North American natives.  We absolutely adore orderly rows of Lombardy Poplars (Populus Nigra) when lining our city streets and making windbreaks on farm fields.  We are not entirely Euro-centric, however.  Your average flower bed and garden will have Asiatic hollyhocks and hydrangeas growing well, and in the warmer parts of the continent African and Australian plants are all the rage.

For that matter, exotics do not even need to be from another continent.  We have an overabundance of Colorado Blue Spruce (Picea Pungens) in the eastern United States and Canada.

These are exotic, having been introduced from the other side of the Great Plains.  Likewise, Floridians are fond of the towering Mexican Fan-Palms (Washingtonia Robusta), and California and northwestern Mexico accept Southern Magnolias (Magnolia Grandiflora) in return, which are also planted northwards as far as the climate can support them when cultivated with care.  The point is that, like much of the rest of the world, North America has a ton of foreign elements in our botanical ensemble.

Now, are these bad?  No, at least as long as we maintain some wilderness and wild spaces, parklands, and make sure that our native ecosystems are not threatened by new species.  Why are they good?  Well, you try eating a baguette made out of corn.  A corn tortilla is amazing.  A corn baguette is a mistake.  Our gardens have been greatly enhanced by combining elements of flora from around the world, and I personally cannot live without a bed of snapdragons planted every year.  I am exceedingly fond of my Bald Cypress growing 300 miles north of its natural range, so much so that I record minute details of its growth every day.  (What?  We all have quirks.)  Don't get me wrong, native plants are lovely and impressive, but variety can be the spice of life, and zone and climate denial is a very fun aspect of gardening.  Not only is variety fun, it is also a wonderful reminder of how we have coped with our environment from the time we first learned to stick something in the ground and make it grow a certain way.  We have developed so many cultivars of flowers, fruits, vegetables, grains, and even trees in a relatively short length of evolutionary timescales.  Exotic plants are essentially an extension of our interaction with the natural world into that same world, a real miracle in and of itself.  While we can decry pollution and resource mis-management, we can applaud leaps in efficiency regarding agriculture and sustainable forestry.  In North America, we have managed to do this really well:



At the same time, on this same continent, we can also see how much we have changed in the past few hundred years.  People who don't think much about the abundance of Blue Spruces probably figure them to have always been there (some even think they grow in straight rows naturally).  People might figure that Los Angeles might not have always had skyscrapers and freeways, but they also might assume there were always a variety of palm trees growing in pre-colonial California (they were not).  Southern Florida has been changed beyond recognition, even in parts of protected areas.  Sometimes the ignorance has extended into professional forestry, with exotic trees being planted instead of the natives that belong and can flourish better there.  While invasives can thrive because of ignorance, non-invasive exotics can sometimes grow nicely but fail to reproduce.  Worse yet, the plants themselves, while remaining benign and non-intrusive, can still host certain insects and pestilences that can devastate our natural flora.  The disappearance of the stately and formerly widespread American Elm (Ulmus Americana) is but one very sad example of what happens when disease travels with garden imports.  We can end up losing our natural heritage at worst, and diminish an appreciation of our natural ecosystems at best.  The most helpful thing to do is to remind ourselves that an exotic is exotic.  It was put there by us, sometimes only survives because of us, and can compete with or make us forget about what was there before us, which happens to be remarkably good at surviving without us (which is a very helpful thing economically, no?).

Exotics are not evil, and by no means do we need to get on an aggressive campaign to eradicate them.  Invasive exotics, on the other hand...