Botany Buddy

It was another beautiful fall morning in the Southern Appalachians, and as I was driving my daughter to school I couldn’t help but be overwhelmed by the clouds in the valleys, the orange hue of fall on the mountains and the vivid colors that were taking over the roadsides.   Escaping in all of natures beauty was perfect for taking my mind off the Radio Disney that was poisoning my ears.  However, just as the Radio Disney was creeping in and squeezing my brain like a vice, those colors on the roadsides did as well.  All of the sudden I realized I was missing the beautiful tones of the White Oaks and Sourwoods against the Hemlocks for the bright red of the Burning Bush against the Honesuckle and Maiden Grass.  As for that beautiful American Holly, I couldn’t even tell what it was for the Wisteria and English Ivy that had taken it over.  By the time I was headed back to the house, what started out as a beautiful relaxing drive was grinding me just as much as that Radio Disney even though I had put on Abbey Road.

That brings me to this.  It always amazes me how as designers and gardeners we are always looking for the next best thing and failing to recognize and reveal the essence of the environment we are in.  In our desire to make our space more perfect, some of the greatest damage to our environment has been done by some of the greatest minds our industry has known.  Here is Asheville the Oriental Bittersweet, Japanese Wisteria, Tree of Heaven, and English Ivy that are taking over our national parks were all the gifts of Frederick Law Olmstead.  In Kansas City it was Arnold’s Red Honeysuckle that George Kessler brought us with America Beautifulc movement.  All of these people have good intentions, but in todays world we can find the information we need to plant responsibly and still have plenty of great options from a  design standpoint.

There are thousands of invasive plants out there, both exotic and native that when taken out of their native habitat can do incredible harm to the environment.  This list is limited to the ten that I see most commonly used and pushed by the horticulture industry.  These are plants that are known to be doing damage to our native habitat and continue to be sold every day.  Why do they do it?  Because of demand from customers (hobbiests and professionals) that don’t know better, existing inventories (that keep getting replenished) and the ease of growing these plant in production and in one’s yard.  When I set out to create Botany Buddy one of my goals was to get this information out, and not only make it accessible, but make available in your pocket at any time.  This list is a fraction of the information consumers need but these plants account for a huge amount of the damage being done.

Ten Commonly Planted Invasive Woody Plants

Burning Bush / Euonymous alatus  This is one of the most popular fall color shrubs in production.  It’s vivid red fall color gives it the name.  It is tolerant of drought, ignorant pruning with gas shears extreme cold and keeps on growing.  As a result it has become a favorite in commercial landscapes and roadside plantings.  In zones 6 and up, the little red berry it gets is extremely viable and is spread by the birds that eat it.  Typically a simple hedge planting in the wrong location can spread to a radius of one mile within ten years.  The native plants they displace include Mountain Laurel, Rhododendron, and Hydrangea.  Which would you rather have?

Bradford Pear / Pyrus calleryana  I can remember when this plant came out in the 80’s and was marketed as “America’s Most Poplular Tree” for the fall color, spring flower, nice tight shape, hardiness, and its fruitlessness.  Besides being prone to ice and wind damage due to that “desireable” branching habit, this tree turned out to be anything but fruitless.  The small crabapple sized berries are a favorite of birds and so is its branching habit.  As a result these can now be found in pastures and waterways throughout zones 6 and up.  Even worse in waterways they are replacing canopy producing trees and raising water temperatures which hurts species such as the Southern Appalachian Brook Trout.

Japanese Wisteria / Wisteria floribunda  Introduced as a favorite for Japanese gardens, its agreesive vining habit will take over anywhere zone 5 and below if left unattended.  It can reproduce by rooting if the brances touch the ground, and in zones 7 and up has vibable seeds.  It is commonly found in Eastern forests along the Blue Ridge  Parkway at elevations between 2500 and 4000 feet.  The populations are highest around cities and especially the Biltmore Estate.  While the flowers are beautiful with the Dogwoods they can girdle and kill any tree they wrap around.  There is a native variety that is finally making it into production.

Japanese Spirea / Spiraea japonica  ‘Norman’ or ‘Anthony Waterer’ is the variety that is the main culpret as it spreads by root as well as seed.  There are many varieties that are supposedly not invasive.  However, all of them have the ability to revert and spread by seed.  One positive is that it is not a favorite of birds becasue the seed is so small.  It has to fall and touch the ground to germinate so some of those parking lot plantings might not be doing as much damage as we think.  If it does escape.  One single stem of this plant can flower and germinate into a colony ten feet wide two years.  This plant is destroying our native wildflowers throughout the Southeast.

Japanese Barberry / Berberis thunbergii  This plant is most commonly planted at your local McDonalds due to its attractiveness with the golden arches.  It is just an invasive as the chain in zones five and up and is as bad for the environment as their food is for you.  The plant aesthetically is probably as numbing to your palet as their food is to your culinary sophistication.  The beautiful red berry entices the birds like a toy in a Happy Meal entices my child.  The red leaves hypnotize the plant’s buyers from a distance like the arches that can be seen from a mile away.  As a result this plant litters our forests like McDonalds’ wrappers do our cities.

Empress Tree / Paulownia tomentosa This plant is not commony found in nurseries, but it is pushed by many major seed catalogs for its ability to grow ten feet a year.  I would think that would tell you something in itself, but people want instant results and that pretty purple flower in May and June.  The tree has nice leaves and a habit like a Catalpa, but most of the year its appearance is cluttered by the seed pods that will spread anywhere they can find soil and light.  This is one of the few invasive trees that wasn’t brought here for planting.  Instead, before there were packing peanuts there were Paulownia!  Before there was styrofoam the seed pods of this plant were used in wooded crates from Asia as packing peanuts, and the trees can now be found along all of the railways throughout the United States.  Unfortunately one of the first places those rails went was our national parks.

English Ivy/ Hedera helix  What would a formal garden be without it?  It would be a lot more interesting and a lot more sustainable.  It is defnitely time to give this plant a rest.  It should really only be used in the concrete jungle and even then limited.  There are many more intersting alternatives live Pachysandra or an all out perennial bed.  This vine spreads by root and can climb in the forest greatly weakending larger trees if not contained.  When allowed to reach heights of 20 and 30 feet it will often start to seed and spread even more.  I haven’t used this plant in over five years, and to be honest with you, my designs, clients, and environment are far better off for it.

Butterfly Bush / Buddleia davidii  This plant is finally starting to make people’s radar as an invasive.  It is one of those that has exploded in variety and popularity over the last fifteen years.  It is still new enough the effects are just starting to take root.  However, in all zones, if these seed falls into a wetland or moist area and gets temperatures above seventy degrees for over a couple weeks, it will germiante and spread.  It is most commonly a problem in warmer mountain and piedmont areas thought the US where moisture running off the mountains provides just this environment.  The seed is a favorite of finches so they move the seed form the plant to summer wilflower patches that share ideal growing conditions.

Scotch Broom / Cytisus scoparius  This plant is to the West and coastal areas what Japanese Spirea is to the rest of the country.  It has naturalized throughout most of the West Coast.  The low growing bushy habit takes out everything in its way, and it has beautiful flowers and evergreen foliage to boot!  This makes it a favorite of growers.  There are hundreds of varieties in production, and the tollerance to drought and long bloom time make it a favorite of retailers.  As for all those little California and coastal wildflowers look out!  This one is eating them all up.

Norway Maple / Acer platanoides  This is probably the most planted invasive tree, but most unknown to be invasive.  This plant had been quietly taking over Poplar forests for the last hundred years.  Poplar being fast growing, straight  and light is now the most popular trim lumber.  It is often selectively harvested leaving just enough light for the seeds of the Norway Maple to germinate and establish quickly.  With yellow fall color like a Poplar’s, from a distance youwould never know the forest had changed, but the natural progression of the forest has.  As the Poplars get older, weaker ones are supposed to fall and thin over time allowing room for grand Oaks to establish along with the legacy surviors.  However, the  fast wide growing maples stunt the forest progression  making 100 year old forests look like they are only thirty years old.

This is just a start and I could go on forever, but these are the ones that I see go out on trucks every day and find hiking in nature every day.  Some people take it personally against invasives and think of the plants as “Evil” or “Bad”.  A wise 90 year old piano teacher once told me…”A weed is nothing more than a flower in the wrong place at the wrong time.”  What we have to remember is that the weed didn’t put itself there.  Either we did, or we created the conditions for it to get there.  There is no greater pervention to the spread of invasive plants than knowledge and education, and both of those are far cheaper than trying to repair the damage that they do.

All of the plants in this profile can be found in Botany Buddy’s Tree and Shrub Finder, along with more photos and information including the native habitats, native ranges, and  cutural information.  Botany Buddy currently profiles 1300 trees and shrubs and our library is constantly growing to bring you the valuable information like this that you need.