Drought-resistant plants are finding a permanent home in everyday landscapes
For many California gardeners, it was the drought of 1976-1977 that first got them thinking about the limitations of California’s water supply and the need to turn toward a more water-thrifty approach to gardening.
Once that dry spell had passed, the urgency of this message receded, but the new awareness that our water supplies are finite fostered big changes in our approach to horticulture.
In the early 1970s, people thought it eccentric to remove the lawn and install a water-wise garden in its place, but after the drought, new norms began to evolve and we all became accustomed to gardens full of California natives, succulents or other plants needing minimal irrigation.
One of the important trends in this shift involved the use of many plants with a tufted habit, ranging from the small, such as society garlic or blue festuca, to the medium-sized, such as Dietes, iris relatives from Africa, to the truly large including the phormiums, commonly known as New Zealand Flax.
Such plants grow like living fountains, with leaves rising up from the base of the tuft like swords or straps. A few such plants have been commonly grown for a long time, as is the case with agapanthus — oddly named lily of the Nile even though its South African home is far removed from the Nile — but now the selection available has increased dramatically.
Some of the new arrivals are bulbs or corms, like the so-called hair bells or wand flowers — members of the genus Dierama. Others belong to the Agave Family, including yuccas and beschornerias. But many of them are drought-tolerant grasses, often with showy plumes of flowers that rise above the clump of foliage.
It is astounding how many different grasses have become common in horticulture, including purple- or red-leaved fountain grasses (pennisetums), blue oat grass (Helicotrichon), and the many muhly species now available.
Even some of the tuftforming plants that are not grasses have a very grasslike appearance and are commonly mistaken for grasses. A good example is the Australian genus Lomandra, sometimes referred to as mat rushes. The common name is a reference to the use of their leaves by native people for making mats.
These plants are as tough and drought-tolerant as they are easy to grow, and they can tolerate anything from shade to sun. This can-do attitude has vaulted them from obscurity to celebrity in a remarkably short period of time. An added bonus is their extensive root system that helps prevent erosion.
Some can grow to be quite large, such as the bigger-growing forms of Lomandra longifolia, but others are more restrained.
One selection we have planted at the Ruth Bancroft Garden is Lomandra longifolia ‘Breeze,’ which grows to be a 3-foot clump of arching green leaves with short spikes of small golden-yellow flowers in summer.
Another outstanding cultivar is Lomandra ‘Lime Tuff,’ which is a little smaller and more upright in its growth habit, with wider lime-green leaves and fragrant flowers.
Lomandra confertifolia ‘Seascape’ has more bluish fine foliage and is also fragrant, but it seems to prefer some shade in inland gardens.