From her living room on the 20th floor of the Philadelphian, a condominium building across from the Philadelphia Museum of Art, Linda Mittman Fishman has thrilling views of the city.
To the left, across Fairmount Avenue, Boathouse Row; to the right, Eastern State Penitentiary; and straight ahead, what she calls "the London view" - a Mary Poppins-like exuberance of narrow streets and rooftops, rowhouses and decks.
Closer in, Fishman has a cool view, too - her own terrace garden, measuring 6 feet by 50 feet, separated by sliding glass doors from the living and dining rooms. It's a delightful splash of geraniums and philodendrons, impatiens, herbs, and tropicals, in hanging planters, over-the-railing boxes, and pots.
"Everything does beautifully out here," says Fishman, who owns three condo units on the next-to-the-top floor and plants on two of the three terraces.
It makes for a fluffy nest of a place, but Center City landscape architect Michael LoFurno knows that high-rise gardens, while offering an unusual, and unusually satisfying, growing experience, come with a unique set of issues.
Weather, a gardener's perennial problem, can be a real stinker for high-risers.
"Weather conditions can be exaggerated up high. There are more extremes of heat and cold in summer and in winter, and there's also the wind to consider," says LoFurno, who designs balcony and other types of gardens. "So plants that would do well in the ground in a home garden might not do so well on a roof or balcony."
In general, LoFurno says, bamboo and other plants with thin leaves dry out faster and can get ripped apart more easily. On the other hand, the dwarf, Japanese-style mugo pine thrives on balconies.
So do Mediterranean plants with silver or gray foliage, such as lavender, sage, and rosemary. They don't mind hot sun, dry wind, or reflected heat and light from adjacent buildings, another peculiarity of high-rise gardens.
"You basically need to do a microclimate analysis," LoFurno says, "which is a pretty big word that just means checking everything out and seeing what happens." (A microclimate is a small space within a larger area, often warmer and more protected.)
Unfortunately, high-rise gardeners often do what their grounded peers do: buy impulsively, without a thought to what's appropriate.
"The biggest mistake people make is just picking plants willy-nilly," says Fern Richardson, whose book, Small-Space Container Gardens: Transform Your Balcony, Porch, or Patio With Fruits, Flowers, Foliage & Herbs, is to be published by Timber Press in early 2012.
"A lot of people have only part sun or full shade because of the proximity of buildings or trees, but they go and buy a bunch of full-sun plants," she says. "They really struggle."
Doesn't sound like Richardson struggles much.
A recently certified master gardener who also designs small-space gardens, she lives in Southern California's Orange County, the land of endless sunshine and plant possibilities.
Seasonal changes aren't very worrisome; maybe there's a screaming wind once every 10 years. And while her second-floor balcony isn't much of a "high-rise" - at least, not like ours in the old-fashioned East - it's about as colorful and interesting as balcony gardens get.
Richardson, who blogs at lifeonthebalcony.com, grows roses and succulents; figs, nectarines, peaches, blueberries, mandarin oranges, and strawberries; and lettuce and herbs, in containers - in 50 square feet.
This, after her grand plan was to become "a rich and powerful attorney" with "a glorious house and plenty of time to garden."
Law school went OK. Bar exam, not so good. So Richardson decided to "embrace where I am right now and make the best of my life where it is," which meant apartment/condo living and "writing with gusto about plants in pots."
Speaking of gusto, LoFurno says that before getting carried away by the novelty of a garden-in-the-sky, high-risers need to consider whether their building restricts what can be placed or grown on a balcony, due to weight load, accessibility, or aesthetics.
Co-ops and rental buildings are most likely to spell out such restrictions, he says; others rarely do. And on the matter of aesthetics, it goes without saying, or maybe not, that trash can-planters are probably not good choices if neighbors can see your balcony. (Even if you live in the boonies, what are you thinking?)
As for planters, LoFurno recommends heavy-gauge plastic pots filled with potting or planting mix made especially for containers.
"I mean potting mix, not potting soil or topsoil," he says. "If it says 'mix,' that's good. If it just says 'soil' . . . 'Soil' is made from who knows what."
Mixes are typically made with ground-up wood fibers, perlite, coconut fiber, and other organic matter, which both promotes good drainage and holds moisture.
(Avoid mixes containing peat, LoFurno says. It's endangered and dries out fast.)
Elsie Hossack, another Center City high-rise gardener, has learned many of these lessons in her 11 years on the 25th floor of the Kennedy House, 2901 JFK Blvd.
Each May, this retired businesswoman and Kimmel Center volunteer buys her plants at Trader Joe's, puts them into heavy pots, and places them around her 7-by-20-foot balcony. She usually goes with the old stalwarts - geraniums, petunias, and marigolds, portulaca, philodendron, and ivy.
"I've tried other things. These plants can really take it," she says.
Hossack's condo faces south and gets a ton of sun and wind. "I have wind that can move furniture. If there was no rail here, I'd go right over," she notes.
The balcony is sparse, but this space really isn't about horticulture. This is where Hossack enjoys her morning coffee and newspaper - now there's a great habit - and cocktails and dinner with friends, followed by serious star- and skyline-gazing later on.
"I feel like I'm in New York City up here," she says of her very Philadelphia views.
Read gardening writer Virginia A. Smith's blog at www.philly.com/philly/blogs/