Mimosa Bonsai, in the tropics, are created from the Leucaena leucocephala (aka L. glauca).
If you've ever thought about creating bonsai from seed, this plant may be the perfect choice.
Unlike many other trees grown from seed, you won’t have to wait long for results.
This page is NOT about the temperate tree Albizia julibrissin, often called the silk tree or mimosa.
Again, we learn the importance of scientific names.
The two plants take very different care and grow differently.
Albizia j. is a temperate tree, the other is tropical.
To keep things straight, we call Leucaena the “Tropical Bonsai Mimosa”.
This “weed tree” most often grows fast and straight, has very little taper, the leaves and seed pods are large.
Some common names for Leucaena are Lead Tree, White Leadtree and even the Weed Tree.
There are over 24 species of Leucaena but the L. glauca (syn. leucocephala ) is the one best suited for bonsai.
It can be found growing wild throughout Florida, Texas, and the Caribbean as well as much of Central and South America and Hawaii.
Although considered an “invasive exotic” in Florida - Honduras, Mexico and many Central American countries value some species of Leucaena as a tree for livestock feed, reforestation, soil regeneration and wood for fuel.
Originally, these were two separate shohin (small) bonsai grown from seed.
One day, I had the idea to slant one and place them together. I was pleased with the result.
Not many people are working with larger specimens of this plant.
(Mainly because it is difficult to find them with nice shapes.)
I saw this curved trunk, collected specimen on display in Hawaii with flowers and seeds.
I spoke with the owner, who told me he purposely let the seeds and flowers grow out especially for the exhibit.
Since so few grow them, he wanted people to know they do bloom.
This foliage can be pruned any time of year. Defoliate frequently. Any time a leaf becomes too large, remove it. (This may happen several times a year - at no particular time.)
Eventually small leaves will develop and be easier to maintain.
Frequent pruning does not seem to damage the tree in any way. I let mine grow a little wild in winter. I then root pruned and cut them back hard in early spring.
Tropical mimosa bonsai roots can fill up a container quickly. You may need to water this plant more frequently than some of your other bonsai.
Root prune your Mimosa Bonsai at least once a year, twice if necessary. Repot spring through summer. (In Florida, I transplanted them throughout the year.)
You can safely remove half of the roots (or more) by cutting them with shears. It’s best not to rake roots as they break easily.
When grown from seed, Leucaena can make a good bonsai (especially shohin). Consider larger bonsai too! They are quick to develop and the aged look of the trunk appears early on.
First let the seedling grow wild, then cut it back drastically. This will give you a decent size trunk very quickly.
Although they will grow just about anywhere, you will have the best results with leaf reduction when grown in full sun or at least high light.
Leucaena prefers to be evenly moist.
This mimosa doesn’t need much encouragement to grow, so use even numbered fertilizers
to keep it healthy. Do not use high nitrogen fertilizer to push new
growth. (Nitrogen is the first number of three, listed on package.) It
will encourage leggy growth.
Because tropical mimosa needs so much pruning, this plant rarely develops flowers as shohin. When it does produce flowers, they are a creamy white inflorescence.
Look closely and (except for the color) they are very similar to the dwarf powder puff. They (also like the Calliandra) are great bee attractors.
Unusual growths sometimes appear on Leucaena, especially older plants. These gall-like formations do not affect the health of the tree. They can be easily removed or refined.
They do not appear on all plants and I have never seen signs of these formations spreading.
Select the buds you want to keep, and remove the rest.
Ben Liss, Ft. Lauderdale, FL purchased his first mimosa bonsai at a Miami bonsai club auction.
It was old looking but needed some work, lots of work. Ben decided an air layer may be the answer.
Click here to see his amazing tropical bonsai metamorphosis.
If you're just getting started see the Beginner Bonsai page
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