Bonsai Penjing Studio in the summer

The Bonsai & Penjing Garden’s studio at Matthaei Botanical Gardens has been transformed into a temporary storage area for the winter months. Photos by: Elizabeth Spencer

By Alyssa Abaloz, University of Michigan student and communications & development intern at Matthaei-Nichols

In winters past, Matthaei housed its temperate bonsai in cold frames, informally known as “the pit.” The trees were lowered four feet into the ground with a steel frame placed above them to keep critters out and allow partial sunshine and water in. “This option became unreliable,” Matthaei-Nichols Bonsai Specialist Carmen Leskoviansky explains, “in terms of the larger trees’ safety and health.”

Our collection of tropical and temperate bonsai has been expanding since the late 1970s, when Dr. Maurice Seevers, former chair of the U-M Department of Pharmacology and a bonsai hobbyist, donated his collection to the organization.

The art of bonsai has been cultivated for centuries by people across the globe. Derived from the Chinese practice of penjing, bonsai creates a sense of contemplation for its viewers. The angle, size, and orientation of the tree’s stance play an important role in conveying a virtue, such as resilience or strength. 

(Right) Pictured here are some of the forms that bonsai can take. These forms may indicate a virtue or a quality, for example adapting to adversity, through posture and training of the tree. Graphic by: Alyssa Abaloz

While the tropical bonsai at Matthaei spend the winter in the facility’s greenhouses, the temperate bonsai need a cold period to complete their growth cycle. More tender broadleaf evergreens, such as the Satsuki azalea, also need a cold period—but not as cold as Michigan natives such as larch can handle. 

Azaleas run the risk of losing branches to deep freezes and desiccating or drying out when their roots are frozen and unable to take up water, even as their leaves are still respiring. The solution comes in the form of a cold greenhouse with a temperature-controlled atmosphere.    

The new storage area also allows easier access to the trees for monitoring and maintenance over the winter.

Designed by Elizabeth Spencer, Matthaei-Nichols facilities manager, and constructed by facilities technicians, a temporary cold-storage greenhouse was assembled in the Bonsai & Penjing Garden’s studio, utilizing space that would otherwise be empty during the winter months. 

The structure is made of 25 millimeter poly-twin Soft-Lite walls to allow 80% light penetration, according to Spencer. “Azaleas are evergreen,” Leskoviansky notes, “so keeping them in the dark too long can affect bud formation and flowering.” 

The fully removable storage system has active heating that initiates when the temperature inside the space drops below 32 degrees Fahrenheit. The heat then ceases once a maximum of 38 degrees is achieved. The controlled temperature allows for the trees’ seasons to start earlier, allocating more time for repotting.

Temperate bonsai in the cold storage area

A view of the bonsai inside the winter storage area. Photo by: Alyssa Abaloz

Funded by a grant from the Stanley Smith Horticultural Trust, this bonsai winter storage solution will be used until a more permanent alternative can be installed, according to Leskoviansky. 

The storage system should ensure a spectacular bloom season for the Satsuki azaleas in early June. Satsuki Azalea Weekend will be held June 6th & 7th and will feature a bonsai exhibition and sale by the Ann Arbor Bonsai Society, Satsuki workshops led by visiting Japanese Artists, a display of blooming Satsuki azaleas through June 20, and more!

Satsuki bonsai azalea

A Satsuki azalea bonsai tree on display at Matthaei Botanical Gardens. Photo by: Scott Soderberg