AERIAL ROOTS!

By Jerry Meislik, Journal Contributing Editor (Whitefish, Montana)

           Only a few species of tree have the unique ability to sprout roots from their trunk or branches. On some trees these roots can form secondary trunks that are as large or larger than the original trunk. On occasion this repeated formation of secondary trunks can result in a tree covering several acres and achieving immense proportions. This type of tree style is called a "banyan."

 

          Plants that can form aerial roots include Pandanus, Metrosideros , Ficus,  Schefflera, Brassaia,  and the Mangrove family. The most well known large trees with aerial roots are in the Ficus family. Of the 1000 or so Ficus species there are some that will readily form aerial roots while others will almost never form them.  David has done many years of research and work to bring out the vast range of possibilities growing one of the great aerial root formers  --- the Dwarf Schefflera.

           The Fuku-Bonsai Cultural Center Entry Tree on a 7' diameter turntable concrete disc.

   
     A banyan is a tree with aerial roots!          .
David with a Chinese Banyan in Hilo
   

   

   How to encourage aerials to start.    The first sign of aerial roots developing are small pink, tan, or brown bumps on the trunk or braches. Over time and given continuing moist conditions these bumps will elongate and become obvious as aerial roots. Should conditions become dry during the formative stages most young aerials will dry up. New aerials do not have a mature desiccation-resistant bark and they are also very fragile and will break with careless or even gentle  handling.

If the conditions are suitable these small bumps elongate and if they succeed in reaching the ground the roots will anchor into the ground and tighten as it firmly roots itself. Over time the aerial can thicken significantly and form a secondary trunk or pillar trunk. For this process to successfully complete the trees must be in nearly constantly humid or misty conditions as often occurs in rainy season in the tropics.

Some trees will form the roots readily even in dry conditions -while others are reluctant and others never form aerials. Ficus carica, the Edible Fig, is very unlikely to form aerials while David’s choice Ficus ‘Mystery’ forms aerials even under relatively dry atmospheric conditions.

 

 

  

         How to encourage aerials to grow after starting.  Anything that keeps the aerial roots moist will allow them to continue growing:   With a mist system, to keep the bark moisten while protecting the roots in the container from rotting due to excessive moisture.  Nearly constant rain if you happen to live in the tropics. Plastic straws split down the side or even PVC pipes for large trees. Keep a bit of moisture in the straw at all times. Wax milk container whose top and bottom are removed and filled with soil and kept moist. The short new aerials are directed to grow into the container and then will grow and root into the soil below.  Sphagnum moss can be wrapped on branches or trunk and covered with plastic to keep the moss moist. Do not remove the moss too soon or the new and soft aerials will dry out.  The moss can be removed months after the aerial has rooted firmly into the ground.

  

Unique styles with aerials.   Probably the most wonderful thing you can do with aerials is to shape a Banyan style bonsai. This tree design has aerial roots, and often multiple trunks connected at the branches.

             How to work with aerial roots.     Aerial roots must coordinate, match or amplify the style of the tree.    Older, woody aerials can be moved from one soil position to another and even wired into position to compliment the style of the tree.    Erratic, wild and uncoordinated aerials do not help improve any bonsai design.

             Additional features of aerials.  Severed aerial roots will normally not sprout branches or leaves except with a few specific species including Burtt-davyi.  Aerials can be fused to the trunk to enlarge the trunk and to form incredible surface root flare.   Aerials can be used to cover large scars.  Aerials can be fused to branch areas that need thickening.

             Conclusion.   If you are growing figs you must make the effort to grow aerials on your fig and to try to develop at least one tree in the banyan style tree. Let me know how this works for you.

             - - - Jerry "Bonsai Hunk"          

 

             COMMENTS BY DAVID:   When I first read his outstanding book:  "Ficus; the Exotic Bonsai"  I was amazed that someone who did not live in the tropics could become an expert on the outstanding tree of the tropics!  In every issue of the Journal,  Jerry continues to amaze me with his knowledge of the Ficus family which clearly is amongst the most exciting family of plants for bonsai and his collection of details and photos!When I began bonsai I really wanted to create a banyan bonsai and so I studied Ficus as much as I could and only switched to Dwarf Schefflera because it is easier and faster to grow. But it also has banyan potential and aerial roots.  Ficus and Dwarf Schefflera have a lot in common.  Some customers with larger amounts of space and lots of large sunny windows want to expand their collections beyond Dwarf Schefflera and I recommend that they consider Ficus --- but to first go to Jerry's website  www.bonsaihunk.us and get his book.  Contact him for more information at jerry@bonsaihunk.us  

     ***   Return to the January  2014 issue of Journal of Tropical and True Indoor Bonsai
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             ©  Mid-Pacific Bonsai Foundation and Fuku-Bonsai, 2014