Butterfly bushes foster love-hate relationship among gardeners

Butterfly bush (B. davidii) with swallowtail-2

Dr. Bob Gilbert – Columnist

Dr. Bob Gilbert

I have never met anyone who disliked butterflies but I have run across many who do not care for Butterfly Bushes.  At first glance that seems to be a contradiction.  Why would you not enjoy a plant that attracts multitudes of butterflies to your yard?  One explanation is that Butterfly shrubs produce seeds – lots of seeds that germinate easily and in abandon. Your neighbors three houses down will get some whether they want them or not.   These seedlings are not selective where they grow except they need full sun.  They are not particular whether the soil they grow in is acid or alkaline.   The good news is that you can prevent the seed distribution by simply pruning off the spent flower heads before the seeds mature and drop.  This stimulates the plant to put out a second flush of blooms but this would require even more pruning.   If you want to extend the period of color display this is a plus.   Because of its seed production and ease of germination Butterfly Bushes are considered invasive but are a still a favorite among many gardeners.  They are particularly effective as the back border of a perennial bed.  

The scientific name 0f the Butterfly Bush is Buddleja or Buddleia (Bud-le-a).   The plant was named in honor of an English botanist Reverend Adam Buddle (1662-1715).  There are 140 species coming from Asia, Africa and the Americas.  Nearly all are classified as shrubs, most are deciduous and a few are evergreen.  They are found in temperate as well as tropical regions.  The clusters of small tubular flowers have colors ranging from pink, blues, purples, strong yellows, red and white.  The blooms are often fragrant.  The pollinated flowers produce a berry that has a single viable seed.  The small tubular nectar producing flowers attract butterflies as well as other pollinators such as bees and moths.  The most popular cultivars are Buddleia davidii from China.

There are some differences in Old World and New World species.  Those of the New World are nearly all deciduous and occasionally have both male and female parts on a single bloom (hermaphroditic) whereas the Old World varieties are exclusively hermaphroditic.   

Buddleia are deer resistant.  Any soil will do as long as it drains well. There are no serious diseases but they do not like wet feet.   The larger varieties are best pruned in late winter or early spring.  They can be treated as perennials by cutting the stalks down close to the ground in late winter or early spring to control height.  Blooms occur on new wood on almost varieties.

B. globosa

A popular species is B. globosa, Orange Ball Tree from Chile, Peru and Argentina.  It has orange 3/4 inch globular very fragrant flower clusters and can grow to 12 feet tall.  It blooms on old wood so pruning is done after it blooms.  It is hardy in zones 7-9.  It is considered noninvasive.  I have never seen this plant growing.  It looks wonderful in the catalogs and I think it would be fun to try it.  However, I am in the woods here so do not have open spaces with full sun.

Butterfly bushes are easily cross-pollinated manually and by insects.  There are now more than 100 cultivars and hybrids.  Some grow tall and there are even dwarf cultivars.  Sterile cultivars exist that do not produce seed. Dirr describes 78 cultivars in his 1998 edition of Manual of Woody Landscape Plants.   For example, I just received a nursery catalog that lists a new cultivar “Grand Cascade.” It grows to 5 feet with 12-14 inch and 4-inch-wide clusters of very fragrant lavender flower spikes that weep or cascade.  It is hardy from zones 5-9.  This is just a single example of what is available.

There is an easy way to remember the difference between a cultivar and a hybrid.  If you cross Plant A with Plant B and always get Plant C, Plant C is a hybrid.   You can always reproduce Plant C either by crossing A and B again or by making cuttings.  All of the seedlings produced will be Plant C.   On the other hand, if you cross D and E and get something different each time, let call it H, this is a cultivar.  Next time crossing D and E you get S a different cultivar.  You never get the same plant.  It is a one-time occurrence.  So, the only way to reproduce H or S or any other cultivar would be by cuttings. “Cultivars” are always written with quotes. It would be important to read about the many cultivars, hybrids and species available before making a final selection to find the one that will perform properly for your location.  There are many options.

A partial list of seedless (sterile) or sterile Buddleia: “Asian Moon,” “Blue Chip,”  “Blueberry Cobbler,” “Peach Cobbler,” “Snow White,” “Pink,” “Miss Ruby,” and “Fever Castle.”  

For further information read Plant Delights Nursery, Inc– “Buddleia davidii: The Butterfly Bush.”  This will have everything you want to know and then some.

I was just about ready to put this article to bed when I ran across an article “Three Reasons Not to Grow Butterfly Bushes”:  1. They do not stay at home 2. Our native insects such as butterfly caterpillars do not use them for food.  Our native insects have no taste for aliens (non-natives).  3.  Our native nectar gathers and pollinators are distracted by them instead of our native nectar producers.  Interesting dilemma.

Given names inspired by plants

Not too long ago I was at a party and we were playing word games.  For example, how many names can you think if that can be used by both males and females?  Also, what given names can you think of that have plants as an origin?  To make it a little more interesting someone has to actually know a person with that name. Fern, Aster, Holly, Laurel, Daisy, Arbutis, Poppy, Jack, Wood, Rose, Joe, Lilly, Heather, Hyacinth, Iris Lotus, Lavender, Rosemary, Olive, Timothy, Flora, Hazel, Forest, Mace, Pansy, Althea, Basil, Dahlia, Linden, Sage, Huckleberry, Moss.

Given names interchangeable for males and females – Patsy, Carol, Lynn, Bobby, Jim, Charlie, Francis, Colin, Taylor, Kelly and Jordan.

Dr. Bob Gilbert co-founder of Smith Gilbert Gardens in , Ga.

Karen Lawrence from Franklin is a professional wildlife and horticultural photographer.