13 years of trial and error with balcony gardening

Some balcony gardeners plant their containers tightly and have full displays right away. Instant gratification makes sense with the North’s short growing season.

In contrast, if the instructions say that plants should start out six inches apart to give them room to expand, I plant them six inches apart. My pots don’t look impressive until midsummer, but I enjoy watching plants grow. Buying fewer of them also saves money.

This year tested my methods. Half of the impatiens plants died after heavy spring rainfalls. More impatiens and some coleus were tried and also withered. The containers looked skimpier than usual in July. At that rate, I’d still be looking at bare soil in the fall. It was time for the big gun: sweet potato vines. 

I’d planned to restrict sweet potato vines to two containers because they’re domineering, but my patience was gone. A few cuttings were rooted in water and planted in the gaps where impatiens had died. By late August the vines had doubled or more in size, sprawling over the sides of the containers. The red and orange flowers of the remaining impatiens plants poked through the lime-leafed vines. Edged with purple and silver wandering dudes, the planters had a multicolor vibe. It wasn’t what I’d planned, but they looked good. 

When I moved into this condo 13 years ago, I’d had a lot of experience gardening a parkway with mostly perennial ground covers and no experience growing annuals in outdoor pots. Notes from my first gardening season here report the result of my inexperience: “I lost six of eight coleus, all of the ageratums, and nine impatiens. I should have waited until Memorial Day to plant.” 

My ninth-floor balcony gets only 2½ hours of sun a day, so sun-loving annuals are out. Those first years, as I experimented to see what would grow here, a gardening friend shared many shade-tolerant annuals and perennials. It may have been the conditions, it may have been me, but they mostly failed. “Haven’t done well with wild ginger, lamium, lamiastrum, oxalis, bergenia, ajuga, creeping jenny, lady’s mantle, catmint, cranesbill geranium, wishbone, monkey grass, sweet woodruff, painter’s palette, and ivy,” I wrote. “Forgot about them.” 

Another friend gave me an Earth Box in which I planted lettuce and spinach. They grew but only enough for a few salads.

Coleus, impatiens, and begonias — the standard annuals of shade gardening — were a mixed bag. Only large, established coleus did well. Impatiens lived some years and died other years, maybe because of the downy mildew disease to which it’s susceptible. Begonias survived, but I wanted something that grows more wide than tall.

The plants that did best were four o’clocks, sweet potato vines, and wandering dudes. 

A neighbor gave me four o’clock seeds, introducing me to the plant. They germinate easily, bloom liberally, and produce seeds for the next year. Too tall for the railing planters, the four o’clocks took over the Earth Box. 

Sweet potato vines were planted a few years ago after I was seeing them in containers all over town. They sprawl wantonly and provide me dozens of cuttings to overwinter. 

The wandering dudes brought home this spring expanded at least threefold, and they’re now inside until next May.

When I began gardening on the balcony, everything was an experiment. Now I gravitate toward certainty, so I plant the reliables. But some change keeps it interesting. Next year marigolds will go in one railing planter. I threw some marigold seeds into the Earth Box this year, and they surprised me by germinating and blooming in the shade. Begonias will replace impatiens. It’s okay that they don’t sprawl because sweet alyssum, a spreader that grew well for me on a parkway, will be seeded among them. Sweet potato vines will start out in only one planter, but they’ll be enlisted for wider service if needed.

Honed by 13 years of trial and error, my balcony gardening guidelines can be summed up this way: Use what’s worked before but also make some changes. Plant sparingly to give plants space to fill in. Have a plan but adjust it if the plants don’t go along. Enjoy and learn.