Myths about Native Plants

I am a passionate advocate of native plants.  And I’m not the only one.  Native plants are as popular now as ever, which may explain why there are so many misconceptions about natives.  So I wanted to dedicate a few postings to busting some myths about native plants.  Now to the first myth.

Myth #1: Native plants are more drought-tolerant than their exotic counterparts.
One of the top reasons people give for using native plants over exotics is that natives are more tolerant of drought than their exotic counterparts.   You hear this claim spread even by knowledgeable gardeners and horticulturalists. 
Hibiscus in its native wetland habitat
Here’s the problem: it’s simply not true.  At least not as a categorical statement.  
Why not?  The claim is based in the assumption that plants in their native habitats do not require artificial watering; therefore, native plants are more drought-tolerant than exotic garden plants.  The problem with this assumption is that native plants refer to any plant indigenous to a local area.  This includes mesic (wet-loving) plants and xeric (dry) plants.  So if you are to compare a wet-loving native Rose Mallow (Hibiscus moscheutos), for example, with your average Japanese azalea, the azalea would be more drought-tolerant.  Native plants are too broad a term to categorically say that they are more drought tolerant than exotics.  Some natives are tolerant of drought; others are not.
The other practical problem with this assumption is many of the most popular natives sold in the nursery trade originate from moist ecosystems.  Why?  The nursery trade focuses on the most ornamental natives, particularly floriferous forbs and shrubs.  The problem is that, as a general rule, plants with lots of flowers are evolved to compete in moisture and nutrient rich environments.  Plants in drier environments must save their resources and flower only under ideal conditions. 
And this is one reason natives get a bad rap.  Neighbor Susie reads on the internet that native plants are more drought-tolerant.  So she goes to her local nursery and selects a beautiful blooming Cardinal Flower (Lobelia cardinalis), which the nursery guy told her attracts hummingbirds.  So she goes home and plops in her Cardinal Flower next to her Russian Sage (Perovskia atriplicfolia).  Of course, the Cardinal Flower is native to moist bottomlands and dies within a matter of months once Susie goes on vacation in August.  Susie looks at her vigorous Russian Sage and decides natives are too fussy and weak. 
What people mean to say when they make this claim is that plants perfectly suited to their environments are more drought tolerant than plants that are not.  The issue is not about native or exotic, but about pairing the right plant with the right environment.  Just because a plant is native to your local region does not mean it’s better adapted to your yard than an exotic.  It helps, of course, but gardeners need to match the plant’s ecosystem of origin with its new environment.   
If it sounds like I’m making an argument against using natives, I’m not.  There is a wonderful native plant for almost any condition in your yard.  It just needs to be the right plant for the right spot.    

Native plants on the Washington D.C. sidewalk in the blazing heat of August, IFC Building.

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