Landscape designer Maria Voris feels rainwater can be harvested anywhere, even in tiny spaces.
She demonstrates how in her mini-garden that won the Tucson Botanical Gardens’ second annual Growdown contest.
The garden sports a wide, shaded swing that overlooks basins of native plants irrigated by contouring the ground.
“I wanted to show that even in a small area you can direct water activity,” says Voris of Petrichor Landscape Design.
Each of three landscape design teams built a garden in a 15-by 20-foot space, slightly larger than a typical one-car garage, in 24 hours over three days in March.
Coincidentally, all three entries demonstrate ways to collect rainwater.
In Voris’ entry, the corrugated steel roof that shades the swing is where rainwater harvesting starts. Its sloping profile directs water to a gutter, which directs the water down a decorative rain chain into the top of a 5-foot-tall cistern.
The steel cistern, which would fill up after 2 inches of rain has fallen, is covered with a rusted steel screen adorned with bee sculptures. It’s a good solution to hiding the shiny receptacle.
“Some people like to show it off,” Volis says. “Other people think they’re the ugliest things they’ve ever seen.”
Water from the cistern flows into one basin where fairy duster, chuperosa and hairy grama grass grow. A stone-paved walkway covers a drain pipe that allows water to flow into a second basin. This one is planted with giant hesperaloe, desert marigold, penstamon and more chuperosa.
The basins keep water from running off the space and instead deeply irrigates the plants within them.
Voris chose those plants because “they do really well in basins. You want to make sure that at certain times of the year (plants in basins) can handle a lot of water.”
Succulents and cacti, which require little water, fill the ground-level space. They include aloe, agave, pincushion and hedgehog.
The wide swing is crafted from a piece of recycled wooden dance floor. A short person can lie on it.
The bee artwork on the cistern screen and on a wood-slat fence extends the theme of a bee habitat sculpture. Solitary native bees use the holes drilled in the sculpture to lay eggs.
The other Growdown entries focused on sustainable practices that produce as well as landscape.
The vegetable garden in Iylea Olson’s space is strikingly tiny. Set right in the middle of her mini-garden, the plot is 30 square feet.
Yet Olson, with LJ Design & Consulting, squeezed in 43 plants: tomatoes, peppers, strawberries and a variety of herbs.
“I used a kind of square-foot gardening method,” she says. “The premise behind that is that you really can pack a lot of plants into a small space.”
Like the winning entry, this garden’s rainwater harvesting system calls for collecting water from a steel ramada roof along a gutter.
A pipe guides the water underground to fill the cistern from the bottom. From there, other pipes lead to the veggie garden and the two planters that contain 18 species of desert plants, including jojoba, chaparral sage, banana yucca and desert milkweed.
Other underground pipes help distribute overflow from the cistern to irrigate a tall pot of beargrass and provide more water for the vegetable garden.
The underground harvesting system, which Olson did not install but shows in a diagram, means the cistern doesn’t have to be right next to the ramada roof.
“Your cistern can be removed from the harvesting surface,” which frees space for other uses, Olson says.
The mini-garden also has recycled metal trellises on which are growing grapevines. There’s also an airy wooden slat fence to shade the ramada from the setting sun.
“The overall idea I wanted to convey was that a small space could be really productive space,” Olson says. That means making room to grow food, gather for social events, attract wildlife and harvest water.
SOLANA OUTDOOR LIVING
Landscape designers Allen Denomy and Micaela Machado’s mini-garden demonstrates how to make rainwater replenish the local aquifer and cool the space.
Porous pavers set apart allow water to percolate into the ground, Machado says. So does the patch of synthetic grass, which also is porous, and the gabion pony wall, essentially a structure of loose rocks inside a steel frame.
Water in the ground helps to cool the air, Machado says, eliminating what’s known as a heat island where hardscapes raise temperatures.
The designers, who work for Solana Outdoor Living LLC, put a small garden on top of the gabion wall. When the tomato, rosemary and parsley are watered, the runoff trickles between the rocks into the ground.
“That’s a very poetic spot,” says Machado. “There’s steel and rock and you have this life garden in it.”
There’s also room for a coop large enough to keep three chickens shaded and protected. On top of the coop they installed a green roof where grass could be grown to feed to the birds.
Rusted metal add contrasting color and texture to the succulent plant palette that includes slipper plant, gold barrel cactus, blue glow agave and yucca.
Entry into the mini-garden through rammed-earth columns and a steel arbor leads to a seating area with a steel fire pit fed by gas. Rebar is sculptured to simulate a small ocotillo fence.
“We wanted to concentrate on urban sustainability,” Machado says.
“We wanted to show there’s tons of potential and opportunity even in small spaces.”