The California Native Vertical Garden
Last weekend I went to see the Drew School vertical garden by Patrick Blanc, the French botanist who started the current green wall craze. He designed a wall in San Francisco that was installed this past February . I was a little skeptical of the whole green wall thing, but then looking up at his wall — four stories high of California natives with over 100 species — my doubts evaporated. The whole thing absolutely overflows with enthusiasm for plants. Two big walls covered in natives, what’s not to love.
A pair of gardeners were doing maintenance while I was there. At first I was a little bummed to see this big orange cherry picker in front of the wall, but then I realized that it was a great opportunity to find out about the wall. I mean, I see this thing and I wonder how much does it cost, how will it age, how much maintenance does it need, and who will give me one for Christmas? Watching them work, I was impressed at how easy the maintenance actually seemed. Like any other gardeners, they cut the plants back with Felcos; they just let the green waste fall to the sidewalk and they barely even had to bend over to work. Progress was steady. It looked quite pleasant.
The plants are essentially growing hydroponically. The black flannel acts as the planting medium for the roots, and water mixed with nutrients drips down the wall, collects at the bottom and then recirculates. This is the first time anyone has ever tried something like this with California natives (he usually uses tropical plants), so the project was considered something of an experiment. Some species like Oxalis oregana or Mimulus cardinalis seem like reasonable candidates for a hydroponic wall, but some of the others like Artemisia tridentata and the Fremontodendron were a shock to me. It’s hard to tell from the photos, but up at the top there’s a Ribes sanguineum, a couple of bushy Mallows, and at least one Ceanothus.
The gardeners said they had done some replanting in September, but this was the first full maintenance pruning. They were cutting things back to do a one-year assessment of the planting and see how everything was growing. After a year of growth, some plants were starting to cover others. The Beach Strawberry was running all over the place, the Dudleyas were getting covered by other plants the same as they did in the Academy of Sciences green roof, the Lupines were short-lived, Penstemon heterophyllus looked like it was also going to be short-lived, but overall the plants were doing really well. The shrubs up top were growing exuberantly, maybe a little too exuberantly; the shade groundcovers down towards the bottom had the best year-round appearance. I found that in the places where the fabric showed between the plants, it didn’t bother me or diminish the effect.
Pretty healthy for a bunch of plants on the side of a building.
I definitely want to make it back in the spring when a lot of the plants have grown back in and are blooming. It really does have tremendous impact when you see it on the street.
This entry was posted on Sunday, December 11th, 2011 at 7:14 am and is filed under california natives, plants, public gardens. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.