This article on Philadelphia’s new rail park sounds kind of cool. Sure, we are copying an idea from New York with the typical one-decade lag, but it sounds like the designers have given some thought to ecology.

The Rail Park’s horticultural design is a “simple palette” with three main layers, he explained.

Hardy London plane trees — “the classic park tree” found along the outer lanes of the Ben Franklin Parkway and throughout the city — will dominate the upper layer. Multi-stem oaks and Kentucky coffee trees will fill in the medium layer, along with shorter redbuds and other flowering trees, American holly and Eastern red cedars. A birch grove will “play off the window boxes” that adorn a neighboring apartment building, like “a domestic landscape writ large,” Hanes said.

The lower level of plants will be more diverse, with arrangements of shrubs and perennials that include:

• Bottlebrush buckeye
• Oak leaf hydrangea and viburnums
• Sedges, tall grasses and ground covers
• Several varieties of fern
• Sumac
• Asters
• Sage
• Goldenrod
• Milkweed
• Alum root
• Wild petunias
• Wild indigo

I can vouch for this part of town being sorely in need of some wildness.