One of the themes at the Tropical Plant Industry Expo in Fort Lauderdale last week was living walls–the concept of growing plants in vertical spaces. This attractive display by Triad Plant Company creates a mosaic of tropical foliage plants tucked into a foam substrate wall perched atop a water reservoir. Essentially, the system is a recirculating fountain which trickles water through the foam to keep the plants’ root systems moist.
That solves one of the major problems with living walls. Watering them can be a messy task. Although I’m all for additional ways and places to grow plants, I’m not so sure that I’d want a living wall next to a carpeted floor! Even with this self-contained system, there are bound to be leaks or dribbles of water onto surrounding surfaces.
Another water-related problem with vertical growing systems is uneven water availability, according to staff at Longwood Gardens, who reported on their experience with their new living wall at the conference. Think back to elementary science class and a demonstration about how much water a saturated sponge holds. When the sponge lies flat, a bit of water drains out of the upper portion of the sponge, but the bottom half remains saturated. When the sponge stands on end, a lot more water drains out of it because there is a much greater distance from top to bottom, and the capillary water (the water held in the pore spaces of the sponge) in the upper portion of the sponge drains out. Similarly, the upper portion of living walls will dry out faster than the lower portion. That means you may need to plant drought-tolerant plants at the top and moisture-loving ones at the bottom if you decide to try this new technology.
Here are a couple more examples of vertical growing systems seen at the trade show:
The planting pockets by WoollyPocket are watered like houseplant dish gardens. The bromeliads are misted frequently to supply the moisture that they need.
It remains to be seen whether vertical growing indoors is just a fad or a trend that is here to stay. Certainly it’s another way to enjoy the beauty and healthy benefits of plants in indoor environments. What do you think? Are they worth the extra effort?