In the Urban Permaculture design work that we’re doing here in Córdoba, Argentina, one of the recurring themes that we’re exploring is how to use climbing, edible plants not just for their fruits, but for their ability to resolve microclimate and livability issues such as privacy, windbreak and passive cooling.
In this article, I’d like to share a few examples of how we’re using edible climbers as an important piece of urban design gear.
First, let’s take a look at an example of an inner patio and walkway that we covered up with a hanging organic roof of pumpkin and passion fruit that grows over a trellis system of wall mounted hooks and wire. It’s extremely low-tech and extremely functional.
This patio is solar facing and normally gets quite hot during the summer, due to the stone tile flooring.
The installation of this “pumpkin roof” allowed us to go an entire summer without using the air conditioning. It also helps resolve privacy concerns, cutting off visual access to our patio from nosey and noisy neighbors. The dog pictured here is Uli. His previous owners (the nosey and noisy neighbors) left him on the rooftop when they moved and now he’s our permacultural pup.
One example which I’m enjoying is this sweet potato plant, which isn’t a natural climber, but is easily guided up the wall using a web of hooks and strings which I installed some time ago. These wall-webs are basically a no-brainer in urban permaculture design. Anywhere you have a growing bed next to a wall, you put in the hooks and the wire, and voilà, you have your vertical dimension ready to populate with edible climbing plants.
The use of climbing plants as green walls also helps to cool inner spaces, reduce noise pollution and to help purify the air.
An important concept, which I explain to my clients and students, is that the walls help us to develop the Food Forest model in any urban space, with edible plants that can inhabit the “climber niche”.
While the plant’s green parts are busy expanding up the wall, the sweet potatoes are growing in the root zone. It’s an example a stacked harvest with different produce cycles available from a single plant.
Here we see an excellent use of the leaves of the sweet potato green wall, sautéed as part of a delicious pasta sauce (with pumpkin flowers and black olives).
And here we have a massive growth of Passion Fruit vines hanging against the wall outside our bedroom window. There’s definitely some room for improvement here in terms of the aesthetic quality of the wall-mounted installation (it’s my house, not a client site), but the effect – especially from inside the house – is pleasing and functional. This green hanging mass provides shade, passive cooling, privacy, fruit, habitat and attractions for pollinators, etc…
Guadalupe’s Rooftop Greenwall Design
This is a client site, where we are working to establish a permaculture garden on upstairs terrace that is totally exposed to the sun and suffers drastic extremes of temperature and climate throughout the year.
Our basic strategy here was to install a wall-mounted climbing grid for edible climbers which – in time – could cover the walls and roofs of a badly exposed rooftop bedroom.
Passion Fruit and Sponge plants getting off to a good start as part of a green wall design.
During our first design workshop we prepared the growing soil for the climbing plants in two milk crates which were then protected from the sun by a modified pallet “growing bench” which is home to a variety of sun-tolerant (not necessarily edible) sun tolerant plants.
In this picture we can see the basic elements of this design: first the milk crated, which house the climbing plants, then the pallet bench, then the sun tolerant potted plants up top.
The thinking behind this particular design has to do with the Zone 4 concept, where the rooftop is considered a semi-wild area with infrequent visits (especially during the midday hours, when the sun is unbearable). With time, the expansion of the roof top greenery can help to lower the Zone 4 classification to a Zone 2 or Zone 1, a place where housemates and visitors can visit comfortably any time of the day.
Below, we can see what the design looks like a couple months after the first installation. It’s worth noting again that the climbing plants (passion fruit and sponge) are growing from milk crates which are totally protected from the son beneath a “growing bench” which is covered with sun tolerant potted plants. This allows for the expansion of the green wall without exposing the growing soil to solar damage.
So far so good on this rooftop design site. Here we have herbs, tomatoes, cactus, succulents and other sun-tolerant plants forming the protection layer for the green climbing wall. Guadalupe, our client, is already thrilled with the new greenery, even though it’s still early days in terms of the passive cooling benefits. She’s already enjoying her rooftop a lot more, and has asked me back to help expand the project (green hanging roof, etc…). We’ll be working on that shortly.
See you next time with more from the concrete jungle!!!
Un abrazo grande!!!