Make Your Own Micro Forest

Route 30 has been carrying vehicles across Pennsylvania for nearly a century. It’s the fastest way to travel east-west across the southern portion of the state, a divided four-lane highway that never stops making noise. For the Horn Farm Center for Agricultural Education in York, the endless roar of cars and trucks speeding past — not to mention the pollution they cough up — had long disrupted an otherwise peaceful site for regenerative farming and community programming.

If only there were a forest to serve as a buffer, the organization’s staff thought. So they planted one.

Trees move at their own pace, often taking decades to reach maturity once planted, but Horn Farm didn’t want to wait that long to address its concerns. Instead, it opted to experiment with the Miyawaki method, an approach to reforestation developed by a Japanese botanist. It places a dense, diverse assortment of native species in close proximity to one another in an effort to rapidly regenerate degraded land. Andrew Leahy, the farm’s education and outreach specialist, describes it as “the marriage of competition and collaboration,” a riot of trees fighting for and sharing resources as they grow.

Miyawaki forests — alternately described as micro, tiny, or pocket forests because of their small stature — have been spreading internationally for years. Katherine Pakradouni, a horticulturalist who has planted several in Los Angeles through her landscaping and restoration business, Seed to Landscape, says the movement “has altered the way people think about reforestation.” The method is still building steam in the U.S., where supporters admire it for quickly establishing young forests with myriad environmental benefits and the ability to reconnect people with nature.

In 2019, Horn Farm planted what it believes was the first Miyawaki-style forest in the Eastern U.S. — more than 500 native trees in a 12-foot-wide strip along Route 30. Roughly 100 feet long, it features five major species and 23 supporting species. Six years later, a thriving overstory of oaks, hickories, and sycamores stands nearly 30 feet tall, surrounded by redbuds, dogwoods, and shrubs including elderberry and viburnum. Bluejays and robins nest in the branches, pollinators gather among their host plants, and predators like wasps feed on agricultural pests. On a bright morning in early October, the forest was thick enough to nearly drown out the sights and sounds of the highway just a few paces away. It’s “infinitely eye-catching” for anyone who spends time near it, Leahy says, but more importantly it’s a haven for biodiversity and a boon for soil, air, and water remediation.

Although Miyawaki forests are often found in urban settings, where land is precious and trees are hard to come by, Leahy says they could be a welcome complement for agriculture, particularly on farms with a regenerative bent.

“As opposed to creating systems where we’re farming in a vacuum and then relying on insecticides and chemicals to make it possible to grow things, why not foster the habitat needed by the very predators that naturally keep those things in balance?” he says.

Horn Farm has gone on to apply the method to other sections of its land, including a flood-prone plot that also borders Route 30. With root systems in place, it stopped flooding, instead serving as a sponge that absorbs water during storms. The forest helps prevent run-off and soil erosion, while supporting the farm’s effort to rehabilitate a nearby stream that feeds the Susquehanna River. To make way for its young forests, Horn Farm first decompacted and aerated soil that had been used for conventional agriculture for decades, then planted its seedlings and gave them a heavy mulching, including inches of leaf litter gathered by the surrounding township.