Living walls bring the garden indoors

There's little room for new plants in my urban yard. Most of the outdoor space is already occupied by some kind of greenery — in the ground, in raised beds and in pots. However, a recent visit to Colita, the newish, Oaxacan-inspired restaurant in south Minneapolis, drove me up the wall, you might say.

I went for the wonderful food and inventive cocktails, but left star-struck by the awesome living wall behind the bar. Lush, leafy and very large, the entire wall is upholstered in plants! I'm not the only customer who's impressed, according to general manager Morgan Lent. "A lot of them cannot believe it is real, and they have to go up and touch it," she said. The plant wall is especially popular in winter, when folks are starved for green and growing things.

I've seen these flat-on-the-wall, foliage-heavy installations in commercial places like Seattle's Microsoft headquarters before, but this one made it seem way more doable for the ambitious home gardener.

Most people can't fit an entire living wall in their homes, but you can apply a lot of the tips from this well-thought-out system by Suite Plants to create a smaller version that works for you. The wall consists of modules called cassettes that measure about 16 by 16 inches. Each cassette is a closed system that contains nine planting pockets that accommodate 4-inch potted plants. The plants are watered by a capillary mat, similar to a paper towel. The cassettes are attached to the wall with brackets to hold them in place.

Most other indoor planting systems, including smaller ones better suited for homes, are based on some variation of this construction. Once I started researching living walls, I was amazed at the number of devices and containers available that make this growing method easier than ever.

Wall gardeners must be aware of drainage requirements and avoid making a mush of their drywall.

Aside from the technical aspect of installing a vertical growing system, most suggestions for planting them sound much like the best advice given for horizontal gardening: Use the right plant for the place. Colita is still learning which combination of tropical houseplants work well together in the same light and watering conditions, Lent said. The restaurant does have a narrow skylight and supplemental grow lights. Ferns are the easiest to grow, pothos requires too much pruning and tends to crowd out surrounding plants, while prayer plant fried in the heat of summer. It's a work in progress.

"The most popular type of living wall has been around for decades; it's the window box. While a hanging window box below a window or on a balcony is the traditional way to use this container garden, I often use window boxes as living walls by hanging them in a row on a wall, fence or gate. Window boxes are easy to find in any garden center and can be a quite inexpensive wall solution."

She plants her series of window boxes densely with a number of colorful cultivars, flowers, foliage or both, fertilizing well for a healthy start. By stacking the window boxes (allowing room for growth) on her fence, she achieves that effect of a solid wall of verdant texture and color.

To see which living wall might be right for you, start small, she advises. "You can also try using small living walls, such as the GroVert by Bright Green, as a small way to get experience with a living wall. You will soon discover what you like — or don't like — about growing living walls, simply by starting out small."

Plant choices are limited only by your imagination, but plants with a spreading growth habit — the spillers from the thriller-filler-spiller trifecta — are a natural for this type of gardening. Here, in our cold climate, you will have to stick to annuals in your outdoor vertical garden, or, if using perennials, transfer them to other parts of your garden before frost hits.

There's no need to limit yourself to ornamental plants — lots of edibles lend themselves to living walls. Think patio-style tomatoes, strawberries and fragrant herbs. Make sure to provide adequate drainage.

Although I've always embraced vertical meth- ods in my kitchen garden, I don't know why I haven't explored this uncharted territory until now. I'm definitely looking at my walls and fences in a new light and dreaming up ideas for next year.