Edward W. Tawyea spent more than 20 years in the Mount Airy section of Philadelphia nurturing a hillside garden with seven tiers. "Every one was its own little room," he says.
Three years ago, in search of more city in the city, he moved to a circa 1827 Society Hill rowhouse. No tiers there, and not as much room, but lots of amenities:
A walled garden 30 by 30 feet square, a small pond and basalt column fountain, one curvy raised bed, star magnolia and crape myrtle trees, and Tawyea's singular sensation: a green wall he built himself.
The eye is drawn naturally to this 3D display, 7 feet high and 16 feet across, ribboned with ferns, mini-hostas, grasses, and tropicals.
Who needs conversation? Just pull up a chair and have a look. That's a good time around here.
Tawyea spent 150 hours and $1,200 on his leafy wall, after experimenting in the basement and garden with materials and methods, plants and scope. The trial was not easy - the word challenging keeps popping into the conversation - but, Tawyea says now, it's definitely worth the effort.
If you have the time.
By 2012, Tawyea finally did. He retired after 25 years at Thomas Jefferson University, where he was director of academic and instructional support and resources and also the university librarian. He's now a part-time consultant.
"I just wanted more time to do this and now I have it," he says as we sit and ponder the wall, something he enjoys doing in early morning, at dusk, late at night.
"I find it a very, very relaxing place to be," he says.
Tawyea grew up in the suburbs of Detroit and remembers, as early as age 5, happily helping a neighbor tend a - horizontal - garden.
"I think you either have this in you or you don't," he says of the green gene.
His fascination with growing vertically was more of "a slow awakening" than an epiphany.
A frequent hiker and backpacker in the Wissahickon, Tawyea used to notice "places there where plants seem to grow right out of the rocks, especially if there is some water seeping down the rock."
Curiosity led to online research and then, naturally, to the work of Patrick Blanc, the French botanist/artist known around the world for 30 years of wildly creative green walls. Tawyea watched videos of those heart-stopping murs végétaux, finally deciding to go with a hydroponic system using water from his new goldfish pond, rather than soil, as a planting medium.
A soilless setup is lighter and cleaner, and eliminates the risk of soilborne pathogens.
Tawyea built a frame for the wall out of 4-by-8-foot sheets of exterior plywood. He covered that with waterproof pond liner and two layers of synthetic, permeable fabric, known as geotextile, for plants to grow in.
Between the layers, he inserted drip-irrigation hoses that, on round-the-clock timers, carry water and nitrogen-rich waste from a dozen Red Comet goldfish in the pond to the top of the wall. The water seeps down through the fabric and past the plants, the runoff returning to the pond cleaner than when it left.
Tawyea cut a dozen rows of pockets in the fabric to hold about 200 plants. He enveloped the roots of each in a thin wrapper made of acrylic felt measuring 1 foot square. "You tuck the plant in the pocket and that's it," he says.
Roots grow through the wrapper and attach to the geotextile fabric. The plants are easy to move, especially before they've grown too much, but they can still be moved later on. "You just have to be gentle . . . when you pull them out," Tawyea says.
His plant palette is mostly cooling shades of green, with an occasional pop of color from a lantana or tropical bromeliad. Parts of the wall get more sun than others, and the light shifts as the day goes on, creating a movable mosaic.
The textures are many, from wispy spears of mondo grass and symmetrical rounds of creeping jenny to thin, white caladium leaves and bulbous green sedums.
Tawyea stayed away from edible plants - they die, get messy - but one he couldn't resist. A chartreuse basil plant, obliviously pre-pesto, thrives atop the wall, which, with proper care, could last a decade.
For those who may want to try this at home, Tawyea has some advice:
Avoid vines. That's cheating.
Keep your color scheme simple. Otherwise, it'll look like a cheesy Christmas tree.
Experiment with abandon. Every gardener is a bit of a scientist and should be willing to fail.
Get the technique down first. Worry about the plant list later. Once you've got it, you can be creative.
And be prepared to work. You need to prune, remove dead leaves, monitor the water pH, spray weekly with hydroponic fertilizer, and pump air into the water for extra oxygen for roots. (So far, Tawyea's had no pests or fungus.)
After all, horizontal or vertical, it wouldn't be a garden without the work.
Contact Virginia A. Smith at 215-854-5720 or firstname.lastname@example.org. Follow her blog atinquirer.com/kisstheearth.