An amazing and beautiful design element in bonsai is the root flare or nebari. Also known as buttressing, this method is a perfect way to make a bonsai appear ancient, grounded and well anchored to the growing medium. Without it, bonsai tend to look like you just stuck a stick in the dirt and the viewer is not awed and their mind remains un-blown.
The Ficus macrophylla or Moreton Bay Fig is an inspiring specimen when it comes to root flare. A powerful beast that is in the business of taking over it’s environment. This strangler fig typically germinates in the canopy of a poor innocent host tree. It remains there until it can send a long skinny root all the way down to the earth. Then it grows. Fast too.
Once the roots get established it out-grows the host tree, completely engulfing it until it becomes a mere skeleton. Forever buried in the core of this beastly banyan tree. They can grow up to 200 feet in height and have an impressive canopy and nebari in older specimens. Like all figs, the fruit can only be pollinated by fig wasps and those fig wasps can only reproduce in the flowers of the fig tree.
The one in the photo above is in a valley in Balboa Park and is over 100 years old. There’s also one in a grave yard near my home that was foolishly planted amongst the graves many decades ago. It has upturned and engulfed dozens of headstones and I shiver to imagine what it’s done below the ground! Creepy huh.
Here’s another huge specimen also in Balboa Park. This one is on the California Registry of Big Trees and was planted for the 1915 Panama-California Exposition. It was listed as being planted from a five gallon pot so it was likely a few years old at the time of planting. It’s estimated that this tree was born in 1910, making it 105 years old today! You can read more about this special tree here.
With bonsai, creating a realistic root flare takes many years to accomplish but there are a few tricks to get you heading in the right direction. When you’re planting your tree you can lay the roots on top of a waterproof and non-porous surface and bury it all in the soil so the roots grow over the surface of this object. Use a saucer, a piece of pottery, a smooth rock or whatever you have on hand. Over time the roots will grow sideways to avoid the object and give you that flare shape you want later. the smaller feeder roots will grow below and around the barrier object as they stretch down towards their water source.
Once this is achieved, you repot the tree but allow these horizontal roots to be above the surface of the potting material and make certain there are plenty of feeder roots below. Eventually the roots will form a nice bark and look like a true bonsai should.
Here are some examples from a bonsai show I went to recently. These are from members of the San Diego Bonsai Club who meet in Balboa Park where I work. An eclectic bunch of rabble-rousers to be sure. I like to observe them from the safety of my museum for fear that I will be pruned, wired and demoralized if I get too close.
In addition to an exaggerated taper in the trunk and the good development of branches, or ramification, creating a realistic root flare is an important style aspect when training bonsai. Ignoring it’s creation will greatly take away from your design so plan ahead! And if you find that a young Ficus Macrophylla has somehow formed on your body, get rid of it before you are completely engulfed! Seriously. That would be insane and wholly inconvenient.