When It Pours…Let Nature Do the Watering

It’s been said that anyone can create a beautiful spring garden. It’s the same with watering. Anyone can create a garden using irrigation; I wanted to try something beautiful without it.

Brandon Tyson

Gardeners. We’re all control freaks, and garden designer Brandon Tyson considers professionals the worst of the lot. After more than twenty-five years in the business, he should know. But he recently seized the opportunity to silence his inner horticultural megalomaniac and submit, for the moment at least, to the dictates of Nature. He decided to let her do the watering.

Tyson set aside a small, curbside section of a garden he was creating in Berkeley (Sunset zone 16/17), attempting to free himself from the “the tyranny of irrigation.” The project proved a perfect testing ground: the bed would receive constant scrutiny from the politically and environmentally conscious Berkeleyites who walk by each day. He also had to contend with the less welcome attentions of a gang of neighborhood deer, who would have preferred a year-round, irrigated salad bar, furnished at his clients’ expense.

“Horror vaccui—fear of void—is another ailment from which most gardeners suffer.” Once he made the commitment to forego summer watering, Tyson discovered he had also eliminated the incentive to pop in a water-hungry plant he knew would then languish. Sometimes, more is definitely less.

Tyson noticed that paring down the plant choices forced him to turn a more critical eye on his composition. There would be no filler to camouflage any mistakes. “Once the winter ephemerals burned away, I (and the rest of the world) would be staring at my errors through the long, hot summer.”

Tyson first dealt with the soil, compacted by years of neglect and heavy construction equipment. Soil preparation focused on improving drainage, rather than on water retention. To this end, he incorporated large quantities of gravel and lava rock, later mulching the completed beds with about two inches of custom-blended gravel, both to suppress weeds and to give a finished appearance.

Choosing the plants was easy. Part of his motivation to create a rain-only bed was to showcase plants that really are not comfortable in a normal garden situation. Although some can tolerate summer water, their summer dormancy leaves them susceptible to smothering by their more rambunctious neighbors, and this can lead to rotting.

As a focal element, Tyson chose a specimen of Yucca rostrata, a marvelous sphere of spiky foliage lifted on a two-foot trunk. Although it can benefit from summer irrigation, it certainly does not need it. Repeating the theme, he included a few smaller, trunkless specimens of this slow-growing species as well.

Selected for their sculptural quality, agaves make up the backbone of the bed. “I found a few spheres of Agave victoria-reginae and gave them pride of place. My austerity program guaranteed that they’d be shown off to their best advantage, with nothing flashy to distract from their wonderful shape and elegant green and white leaves.” Tyson was rewarded when a few of the less well-known agaves burst into spectacular (although fatal) bloom. “But you almost always get a litter of ‘pups’ after the show is over, so I feel it’s well worth it. There’s nothing quite like an agave in bloom. They are so dramatic!”

Dark red rosettes of Dyckia ‘Jim’s Red’ continue the theme, with the added advantage of colored leaves and orange flowers. Like many agaves, dyckias bear vicious spines, so Tyson placed them well away from pedestrians. Tyson feels that terrestrial bromeliads, such as Dyckia, Hechtia, and Puya, are under-utilized, although they are just as tough as agaves and yuccas. Continuing with succulents, he also included unarmed selections of Echeveria and Dudleya, scaling down the rosette motif.

To loosen the architectural composition, Tyson chose a low, blue grey form of Mediterranean fan palm (Chamaerops humilis ‘Algerian Grey’). This one never develops the trunk found on the more common forms, so it will stay in scale with the rest of the planting. The crisply divided leaves complement the more robust shapes of the agaves, and reiterate the motion and color of the taller Yucca rostrata.

The most surprising element is the lip fern (Cheilanthes lindheimeri) with which he surrounded the agaves. Ferns are the last thing anyone expects to find nestled around succulents, but this one is intolerant of summer water and tends to die out if pampered too much. Here, it has thrived and multiplied without irrigation.

Tyson’s one concession to unabashed glamour would have to be the Brunsvigia josephinae. Unlike other, more water-tolerant, summer-dormant bulbs, these large South African amaryllids resent any form of summer irrigation, demanding a dry rest period. “But when this diva explodes into bloom, you will forgive her demands.” Like many divas, this one is large (the bulbs weighed ten pounds each), rare, and expensive, but well worth the trouble and cost. As tempting as this beauty’s blood red blossoms might be, her audience of passing admirers has been respectful, leaving the flowers unpicked and allowing her to form spectacular seed heads that are just as stunning as the flowers.

Exotic on a much smaller scale is a South African daisy (Gazania ‘Christopher Lloyd’), a cultivar with beautiful, orange-pink flowers, each with a beetle-green center. A few drought-tolerant species of Pelargonium, also from South Africa, complete the picture.

Each year, Tyson experiments with winter-growing ephemerals, but he’s vigilant about introducing anything that might smother the key players and become a nuisance. Eventually, as the bed fills in completely, he might even stop doing this. Maintenance is relatively minimal, consisting of removing the spent ephemerals after their winter show, and occasionally washing off the dust and debris during the summer.

Tyson doesn’t know if he could exercise enough restraint to create a completely rain-dependent garden. “I’m in love with too many plants, most of which require a little more water than Nature alone is willing to provide. But I’ve enjoyed this exercise, and how it has made me limit my palette and refine my design.”

Plant List for a Rain-only Berkeley Garden

Agave ‘Sharkskin’
A. ‘Felipe Otero’
A. victoria-reginae
Brunsvigia josephinae
Chamaerops humulis ‘Algerian Grey’
Cheilanthes lindheimeri
Dudleya thraskiae
Dyckia ‘Jim’s Red’
Echeveria ‘Fleur d’Or’
E. ‘Green Goddess’
Gazania ‘Christopher Lloyd’
Yucca rostrata