Nate Benesi has a vision. He sees Southern California gardens lush with lawns, roses, and aloes that never need to be watered. That’s right. Benesi intends to compile a palette of plants that once established in the garden after a year or so will be watered exclusively by the rain. To this end, Benesi has planted an experimental collection of plants dubbed the San Gabriel Waterless Garden. It is located at the Nature Center of the San Gabriel Dam Recreation Center, at 15501 E. Arrow Highway in Irwindale.
This is clearly a labor of love as Benesi works as a volunteer on this project under the auspices of the San Gabriel Mountains Regional Conservancy. It’s not entirely fair to form a first impression of the plants on display since they are still recuperating from a blistering summer, and many of the roses are already leafless.
There is one criterion of a rose’s durability that I never considered but is vital in screening the 13 rose varieties being tested by Benesi. That criterion is sensitivity to sun scorch. You may have noticed that trees in young orchards often have their trunks painted white and the reason for this is the sensitivity of their tender bark to sun scorch. The paint reflects the sun and prevents the bark from scorching and cracking.
It turns out that roses display this same sensitivity and Benesi shows me varieties with stems that have been blackened from sun scorch while others are completely green, a sign of their resistance to hot summer sun. Typically, it is the southwest side of a trunk or stem that is most severely scorched since when the sun is in the southwest portion of the sky, its heat is most intense.
Benesi devised another method for testing heat tolerance of roses. After a 100 degree plus heatwave a few years ago, Benesi visited the rose gardens at the Huntington Botanical Gardens in San Marino and the Descanso Gardens in La Canada Flintridge. Strolling among the roses there, Benesi took down the names of the ones that looked vibrant despite the extreme heat. Among the tougher roses were certain David Austen varieties. Benesi was surprised since — coming from England where rain is never in short supply — you might think David Austen roses would necessarily be more water needy than other roses but at least where selected varieties are concerned this is not the case.
Benesi began planting in 2018 and one David Austen rose known as ‘Evelyn,’ with soft apricot colored blooms, is now living a waterless existence. Four David Austen shrub roses planted in his garden are still classified by Benesi as “not waterless yet”: red ‘Benjamin Britten,’ peachy pink ‘Lichfield Angel,’ pink ‘Scepter’d Isle,’ and orange ‘Lady of Shallott.’ Two roses of note are still in bloom: the pink Mrs. B.R. Cant, a tea rose, and a white noisette rose known as ‘Mme. Alfred Carriere,’ which can be trained into a climbing specimen.
The obvious question for someone searching for waterless garden candidates is: “Why not just select cacti and succulents that are known for their ability to withstand drought?” Benesi answers that he wants to include plants known for their flowers, so naturally he has been drawn to the prospect of drought-tolerant roses. Plants that change with the seasons are also a priority for Benesi and most succulents look the same throughout the year except for a brief flowering period.
Other than roses, Aloes take center stage in the San Gabriel Waterless Garden. Healthy clumps of Aloe vera are present in large numbers. The origin of the word “Aloe” is found in both the Hebrew and Arabic languages and references its curative properties. In ancient times until today, it has been extolled for its therapeutic value, especially as a skin emollient and for stomach ailments. Aloe vera is thought to be native to the Arabian peninsula, North Africa, and the Canary Islands, although nearly every other Aloe species is indigenous to South Africa. At the present moment, Aloe dawei is exploding with orange flowers in the waterless garden.
Incidentally, the name Aloe vera, meaning true aloe, was not given until explorers began to bring back agave plants from Mexico and the American Southwest to Europe. By then there was a wide familiarity with aloes. Because of agaves’ resemblance to aloes, the name Aloe vera came about, distinguishing it as the authentic aloe. The botanical name Aloe barbadensis is used interchangeably with Aloe vera, referencing its lush growth on the island of Barbados, even though it arrived there as an import from Africa.
There is a botanical relationship, however, between aloes and agaves. At one time, both groups were classified as belonging to the lily family but, in recent years, Agaves have been reclassified, and are now considered to be members of the asparagus family. Benesi has planted Agave ‘Mateo’ on account of its distinctively green foliage, uncharacteristic for an agave but a lively contrast to his other selections, which either lose their foliage this time of year or, even if they don’t, have generally gray or dull green leaves.
It should be noted that soil drainage in the ground upon which the waterless garden has been developed was almost nil, and so the ground had to be heavily amended. IERCA (Inland Empire Regional Composting Authority) Soilpro Products Compost was selected as the amendment for soil improvement. According to the ierca.org website, this product consists of “composted biosolids (treated sewage sludge), forestry products, yard trimmings and stable bedding.” It is sold at many local nurseries. Through mixing 140 cubic yards of this product into the native soil, raised beds were created and reasonable soil drainage was assured.
One of Benesi’s most successful waterless plants is French lavender (Lavandula dentata candicans), whose joy is attested to by the fact that several of its seedlings have sprouted up around one of the mother plants. When any plant self-sows, you know you have found a sweet spot for its growth.
Portulacaria afra ‘Prostrata’ or trailing elephant’s food is also thriving. I have this plant in my own garden with one significant difference. The leaves on my plant are several times the size of the mini-leaves on the specimens found in the waterless garden. I do not know if this difference is due to less water here since I barely water my plant, if at all. It could be that the waterless variety here is a mutation of the much larger-leafed prostrate variety that is commonly seen.
I was grateful for Benesi introducing me to Hesperaloe ‘Brakelights’ with its unusual burgundy red flowers and to the spineshrub (Adolphia californica), which consists of nothing but prickly stems, but it possessed with a certain exotic elegance nevertheless. Spineshrub is a critically endangered species so it’s nice to know it has found a happy home in the waterless garden.
Tip of the Week: Benesi is growing bulbous meadow-grass (Poa bulbosa). It is used to control erosion and may be suitable for overseeding as a winter grass on dormant lawn types such as Bermuda and Kikuyu. It will die back as winter warms in April but will come back the following year if it is grown on bare ground due to the perennial bulbous growth at the base of its stems and the bulbils that form above ground at the base of its flowers, much like bulbils seen at the base of the flowers on certain agave species.
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