Horticulture professor hopes to grow more of swing tree species

Swing tree’s days are numbered but there might still be hope for its offspring. (File Photo/ The Daily Campus)

While it is currently too early to determine the effectiveness of treatments designed to help the University of Connecticut’s swing tree, a UConn horticulture professor has collected its seeds in the hopes of growing more trees of its type.

UConn spokesperson Stephanie Reitz said Dr. Mark Brand, horticulture professor and co-chair of the UConn Arboreum Committee, gathered seeds from the swing tree this fall and has germinated a small portion. He already has more than 75 seedlings growing, Reitz said.

“Right now, they’re growing slowly due to the short days and low light levels of winter, but we expect them to begin growing rapidly in the spring,” Reitz said. “With the amount of seed he’s been able to collect, we could produce many more seedlings and potentially give the swing tree a second life, so to speak, with many descendants.”

Brand said the swing tree is a Dahurian birch, also known as a Japanese black birch, which is a fairly rare species of tree.

“I wanted to grow some new Dahurian birch trees to re-establish the species on campus in the UConn Campus Arboretum so it wouldn’t be lost from the collection, in case the swing tree doesn’t make it,” Brand said.

Last spring, it was discovered that the top of the tree had trouble leafing out, and it currently appears to be dull and somber with dehydrated leaves and droopy branches, UConn tree experts told the Daily Campus.

Aris Ristau, director of Building Services, told the Daily Campus that UConn tree specialists have implemented a treatment plan to help improve the swing tree’s health.

The soil around the tree will be given organic soil enhancer and biostimulants to help nurture the health and growth of the tree. Tree experts have also been aerating the surrounding soil so the water can reach the major root area, according to UConn Today.

“We’ll know much more (about the effectiveness of the treatment) when we see how well it performs in the spring, both in terms of the growth and breaking of its buds and how well it fills out with leaves,” Reitz said.

To grow the new trees, Brand said he collected strobili that birch trees hold their seeds in. The strobili are cylindrical structures made up of seeds and bracts that fall apart to release seeds when they are ripe.

“I collected a bunch of strobili off of the tree as they were turning from green to tan, signifying that they were ripening and that the seeds were mature,” Brand said. “I allowed the strobili to dry in a paper bag and then broke them up into seeds and bracts.”

Brand said birch seeds will germinate when fresh if you provide them light exposure, so he sowed them in clear plastic trays which were covered with clear plastic lids to retain moisture. The trays were placed directly under fluorescent lights with 16 hours of light and eight hours of dark for each 24-hour period.

The seeds began to germinate in about 14-16 days, and once they were about three-quarters of an inch tall, holes were made in the tray lids to reduce the humidity and get the seedlings used to drier conditions, Brand said.

“After a couple of weeks of acclimation to drier air, the seedlings were potted up into plug trays and moved into the greenhouse. The plug trays were covered with clear plastic domes for a couple of weeks to further acclimate the young seedlings to the greenhouse environment,” Brand said. “Finally the lids were removed and the seedlings are being fertilized and grown under lights in the greenhouse to provide them with 16 hours of light per day.”

Brand said part of his decision to germinate the seeds was that he thought there may be people who would be interested in having an offspring tree from the UConn swing tree.

“I believe there are plans in the works to develop a new ‘swing tree’ type of swing destination on campus, and it would be nice to be able to incorporate swing tree progeny in the plantings around this new swing location, even if the swings are not directly attached to the birch trees,” Brand said.


Gabriella DeBenedictis is a staff writer for The Daily Campus. She can be reached via email at gabriella.debenedictis@uconn.edu.