By Anne Levin

A traditional forest can take up to 100 years to mature. But a microforest — a diverse set of native plants and trees on a small plot of land, usually in an urban setting — can take as little as 15 years to reach full growth.

With that in mind, Princeton Council passed a resolution at its February 24 meeting authorizing submission of an application for a Sustainable Jersey grant of $10,000, to cover costs related to the town’s first such project. The 5,000-square-foot site is on an underutilized area of grass and invasive plants at Quarry Park, next to Princeton Housing Authority’s Lloyd Terrace at Spruce Circle affordable housing complex.

Partners in the project include the Princeton Recreation Commission, the Princeton Shade Tree Commission, the Princeton Environmental Commission, Sustainable Princeton, and the Princeton Housing Authority.

“We have determined the area, and which plants to use,” said Inga Reich, the municipality’s open space manager. “We are working with residents, students from Princeton University, and Princeton Middle School, for help with planting and maintenance. And volunteers from the neighborhood have started to remove ivy from the area.”

The town has funding set aside should the grant not come through, Reich said.

Microforests – also known as Miyawaki forests, or tiny, mini or pocket forests – were conceptualized in the 1970s in Japan by plant ecologist Akira Miyawaki. Trees of varying heights and shrubs are densely planted to create a fast-growing forest, which will mature quickly. Using what is known as the “Miyawaki Method,” a diverse set of plants and trees are put into a dense space.

The idea for planting a microforest in Princeton came from the Princeton Environmental Commission as a response to the loss of trees caused by development projects.

“Microforests encourage a lot of native plants in one area, which helps with biodiversity,” said Jenny Ludmer, program manager at Sustainable Princeton. “Many of these will be trees, which helps with stormwater control.”

In a letter to Council outlining the proposal, Reich said a combination of staff and volunteers will be used to completed preparation of the site followed by planting in the second half of this year.

“It will also provide a unique learning environment for school and university students. Princeton Public Schools, Rutgers, and Princeton University have been solicited to assist in monitoring tree survival, changes in local biodiversity, and other environmental benefits as the microforest is established,” she wrote.

Ludmer said, “The idea is that when you put plants in a much denser space, the competition between them is stronger so they grow faster. It mimics what happens in a normal forest.”

According to the town’s website, the microforest will consist of many native tree and shrub species found in the remaining old-growth forests of the region — including red maple, white oak, American hornbeam, tulip poplar, blackgum, sweet pepperbush, nannyberry, and spicebush. Visitors will be able to walk a trail and rest on benches.

“The establishment of a microforest in Princeton is a positive step forward in our efforts to foster climate resiliency, promote biodiversity, slow stormwater runoff, and lessen the urban heat island effect,” wrote former Councilwoman Eve Niedergang on the town’s website. “In addition to its positive ecological benefits, it also presents an opportunity for collaboration between Princeton’s Environmental, Shade Tree and Recreation Commissions, Sustainable Princeton, and the local community. Finally, the location of the microforest adjacent to Princeton Housing Authority’s Spruce Circle fosters environmental justice and inclusion for all Princetonians.”