Brazilian Rain Bonsai Pithecellobium tortum

As the name implies, the Brazilian Rain Bonsai is native to the lush rainforests of Brazil. Not only is this a local favorite in Central and South America, but it has also captured the hearts of many and henceforth garnered recognition as one of the tropical world’s most beautiful and one of the most popular Bonsais.

This hardwood legume goes by the Latin name Pithecellobium tortum. And just like its relatives, the Brazilian Rain Tree has compound leaves, sturdy stature, and is quite spiny. Its tiny light green leaves fold up at night or whenever exposed to subdued light and open up once again when the morning comes. It also grows fragrant yet fuzzy puffballs of flowers. The overall appearance of this tree gives a unique look making it one of the most interesting rainforest bonsais. (It surely is honing all the accolades in the bonsai world.)

While they can tolerate more than 30 degrees Celsius of temperature and grow in full sun in nature, the P. tortum still appreciates some shade during the hottest of tropical summers. The sandy growing environment of Brazil shows how well these trees thrive in dry conditions. But you can also expect this tree to survive and thrive as a houseplant all year round since it prefers to be in a container where it is evenly moist.

History of the Brazilian Rain Tree in the U.S.

Going back to the origins of P. tortum in the United States, the late Jim Moody of Juniper Bonsai (located in Florida) received seeds from his sister-in-law, who collected them while in Brasilia, Brazil. Jim then planted the seeds and was able to produce five germinate. But he didn’t initially know the tree’s species, and so it was misidentified as a Samanea saman (commonly referred to as the monkey pod tree) and most often just dubbed as the “mystery tree.” Later on, though, it was correctly identified as Pithecellobium tortum. Jim then came to grow the first of his raintrees for seven years. He styled it in an informal upright way in a small cascade bonsai pot. That specific specimen eventually acquired national recognition through the book ‘Great American Bonsai’ and Bonsai Today magazine. Jim eventually started propagating more of the P. tortum from cuttings taken from the original one. Today, several nurseries and websites alike sell Brazilian Rain Trees, many of which are direct descendants of Jim’s tree dating back to 1978.

Moreover, Jim deviated from the traditionalist way of shaping bonsai trees and trained his Brazilian Rain Tree “his way.” And “his way” proved to be the perfect way to display the tree’s amazing trunk. Unfortunately, Jim passed away back in 2003, leaving his grandson Alan Carver to carry on the tradition of growing bonsais of the tree.

How to Care for Your Brazilian Rain Tree Bonsai

Back in its homeland, Pithecellobium tortum, also known as Chloroleucon tortum, grows along the coast of Rio de Janeiro. It also “snakes” low across the sandy soil. Due to the heat of the sand, sea breeze, and lack of nutrients, many have grown to be old and gnarly. It is also noteworthy that these natives have found their way on the ‘Critically Endangered List’ from being once a highly regarded collection of bonsai.

In another case, another unique factor of this bonsai is the trunk’s ability to flatten, become fluted, twisted, and even form a triangular shape. But if yours didn’t develop into any of those characteristics, you can still have a handsome, smooth, muscular trunk.

The Brazilian Rain Tree can also grow for an average height of 14 inches, a width of 10 inches, and a lifespan of more than a hundred years.  


You can grow P. tortum from either seeds or cuttings. Too, growing this species can be done through the process of air-layering.

Position and Lighting

You can choose to keep your Brazilian Rain Tree bonsai indoors. But keep in mind that it will need plenty of light (and by that, we mean a lot). During the growing seasons of spring, summer, and aall, make sure you place it in a sunny location outside. Then take your tree back inside the house at a window that faces south or is under grow lights when temperatures are below seven degrees Celsius during the winter. Another tip would be to provide your tree with an east or west exposure. And about four to six hours of sunlight daily will suffice, but providing more is actually so much better.

Temperature Requirements

As mentioned before, the Brazilian Rain Tree can tolerate the upper 30 degrees Celsius range. This capability is not for a long time, though, so make sure to bring your tree indoors for the winter.

You also need to consider another factor, which is humidity. During the colder months, place your tree in a shallow tray filled with a layer of gravel and water. Doing so will provide moisture around your tree. It works because once the water evaporates, it reduces the loss of moisture caused by modern heating systems. Another option would be daily spraying the leaves and branches of your tree with water. This method will coat them lightly and allow them to be dried again the next day. Basically, your tree needs to be evenly moist all the time. You can even use a moisture meter until you get the hang of the requirements of your tree.

Watering Needs

Cultivating a Brazilian Rain Tree bonsai requires special attention that is slightly different from what the plant gets from nature.

When it comes to properly watering your bonsai, you have to ensure that the soil is evenly moist after. Furthermore, the soil must be dry before you water it again. And while your bonsai needs a great deal of moisture, overdoing the watering will lead to the growth of mold and mildew, root rot, and overall poor tree health that can weaken and even kill it.

In addition, never allow the root ball of your bonsai to dry out completely. The watering of your Brazilian Rain Tree must never be neglected. Apply water until it is running out of the holes of your pot. In general, it is not about how you water your bonsai; instead, whether your tree has been well watered when you are finished.

Soil, Feeding, and Fertilizer

Since your Brazilian Rain Tree bonsai grow in specialized and shallow pots, they only need less soil than your average potted plants. But unlike the normal growth of potted plans, your bonsai cannot achieve that kind of growth because of the lack of adequate sustenance from the soil. This is where liquid fertilizers come in. You can do a weekly feeding during the growing seasons and monthly through winter to keep your bonsai strong and healthy. As for the portioning, only use half the recommended amount on the packaging of general use fertilizers to avoid overstimulating your tree.  

If you want a different way of providing fertilizer aside from direct contact, you can also choose to spray on your tree’s leaves and green growth. A 50-50 mix of fertilizer and water sprayed evenly across the foliage is guaranteed to make your tree respond well.

Pruning, Styles, and Wiring

When pruning, keep a small nub of branches and twigs to allow possible die-back. Many bonsai enthusiasts refrain from using concave cutters on their Brazilian Rain tree for this reason. But this can be refined later on. You can then opt for the clip-and-grow method to develop shape once your tree’s initial trunk and branch shape are already established. And when you do decide to wire, it would be best to use nylon strips for the green branches and leave the wire only to tie down the branches. Usually, the styles used are upright because of your tree’s nature to grow straight if unaffected by winds.


Perform reporting periodically on your Brazilian Rain Tree bonsai when the root system has filled the pot. The telltale would be when you can clearly see roots coming out of the bottom of the pot. If this happens, it’s about time to repot your bonsai. Usually, this equates to two to four years, depending on your tree’s environment.

Repot during mid-summer because this is when your tree is the least fragile. Remove your tree along with its soil from the pot. Then trim away ¼ of the root mass or no more than 1/3. You can report it in the same one or find a new and bigger pot. After repotting, make sure to water your bonsai thoroughly.  

Pests and Diseases

Your Brazilian Rain Tree is resistant to most pests and diseases but can still be infected by nematodes. These pests provoke root nodules integrated into your tree’s root system. In this case, you can use nematicide. But if kept indoors, your bonsai can be bothered by aphids, white flies, and spider mites. Control them through specific pesticides. You can check out another article solely about getting rid of pests and diseases. 

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