Can Philly become a hothouse for bananas and pineapples as the climate warms?

As climate change warms Philadelphia, the plants that can be grown in the city will change, too.

The nonprofit Philadelphia Orchard Project believes that fruits more associated with more southern climates can be raised locally and is experimenting with what’s possible to grow.

The Orchard Project has erected two high tunnel unheated greenhouses at the Woodlands estate, a 54-acre protected national historic landmark in West Philadelphia. The group helps 69 partners, mostly community orchards in formerly vacant lots, figure out what to plant, how to plant, and how to harvest.

The high tunnels will serve as living labs to grow more exotic fruits and vegetables, according to Phil Forsyth, the Orchard Project’s co-executive director. The plastic covered hoops are 22 feet wide, 48 feet long, and 14 feet high and naturally heated by the sun in winter to help plants survive inside. The tunnels are vented and can be covered to block light and allow temperatures to drop if needed.

“This is our newest exploration of what’s possible in terms of perennial crops in Philadelphia,” Forsyth said. “We saw this project as an important way to investigate crops in a changing climate.”

Some community groups Forsyth works with are already using high tunnels to grow tomatoes and greens.

The new tunnels at the Woodlands will take that further by growing crops that would be new for Philadelphia gardening. Although not heated, they will allow fruit trees to survive winters as Philly moves up in the U.S. Department of Agriculture’s hardiness zone.

The USDA designates 13 zones, each indicating the likelihood of success for different plants in a given area. Zone 1 represents the coldest conditions, while Zone 13 signifies the warmest. Each zone is further divided into subcategories A and B. Forsyth notes that Philadelphia was initially classified as 6B when he arrived in the city in 2006, but it has since shifted to 7B. This change significantly impacts the range of crops that can thrive in the region

The Philly Orchard Project is preparing for a shift into Zone 8 in coming years by planting olives, bananas, guava, and hardy citrus, including yuzu and kumquat.

Since the 1970s, the average spring has warmed more than 2 degrees in the region, the average summer more than 3 degrees, and the average winter more than 5 degrees, presenting challenges but also opportunities.

“We’re also exploring different seasons of production for fruiting crops,” Forsyth said. “So we are planting some of the more standard things like strawberries and raspberries and fig trees and are getting fruit a month sooner than normal and later in the fall.”

Forsyth sees this “as a silver lining” to the “very black cloud” of climate change.

“As the climate warms, it’s going to be possible to grow other things, or maybe less, as we get warmer,” he said. “We want to be ready to adjust to those changes and share that knowledge with our community partners.”

That experimentation might allow people who have immigrated to the U.S. from hotter climates to enjoy fruits native to their homelands. Forsyth is most excited about experimenting with bananas. In recent years, a fungus has threatened the Cavendish, the typical yellow banana bought by Americans in supermarkets. The Philly Orchard Project has planted two other varieties of bananas: dwarf Orinoco, which is native to Venezuela, and Raja Puri, which is native to India.

“I’m pretty certain we can get the plants to survive the winter and get it to fruit,” Forsyth said. “We’ll give it some nighttime winter protection, probably by surrounding with fencing and stuffing it with fall leaves as additional insulation.”

He hopes that those efforts, combined with the high tunnel, will allow the nonprofit to be fruiting bananas in the city.

The Philly Orchard Project, which has its headquarters at the Woodlands, also helps community groups plant more commonly grown fruit and nut trees, berry bushes, fruiting vines, herbs, flowers, and vegetables like asparagus and Jerusalem artichoke.

Ty Holmberg, cofounder of Sankofa Community Farm at Bartram’s Garden, is one of the Orchard Project’s partners, and was started with a motivation “rooted in the African diaspora.” The farm’s orchard contains 60 trees that include figs, pawpaws, cherries, and pecans. Holmberg credits the Orchard Project with helping make the farm a success.

Holmberg said the growing season has changed in the years since Sankofa began.

“We’ve seen such a change in the last 14 years in the first frost date and the last frost date from climate change,” Holmberg said. “Since we started growing it has extended about three weeks on each end.”

As a result, figs routinely produce two crops, without the second crop failing from an early fall frost. And tomatoes can be planted in early April, instead of the beginning of May. However, Holmberg said that comes with a price.

“The benefit is that you have a longer growing season,” he said. “The downside is that … all of the insects or diseases that might have been killed off with a harsh freeze in winter time, we’re seeing that carry over from season to season. So it’s putting us kind of out of whack.”