By Jim Downer
Landscapes contain many variations such as perennial gardens versus annual color beds that are used for amenity and other purposes. Plants that are aesthetic, low water using, slow growing, low maintenance and high value are “enduring” plants. Enduring plants provide high landscape value because they are desirable plants that increase in worth as they age.
Many gardeners prefer fast growing plants that quickly fill space. Rarely are these sorts of plants “enduring”. Slow growth gives a plant a certain toughness and resistance to disease and insects; the slow growth is offset by their ability to survive adverse or changeable environments. Slow growth also contributes to reduced maintenance because slowly growing plants require little pruning and thus generate little excess. Slower growing plants also use less water, and, after establishment, are somewhat-to-extremely drought tolerant.
Enduring plants may be ground covers, shrubs, trees or herbaceous perennials. Enduring plants can be lost in a lush landscape, but are often specimens that command focal attention in the landscapes they occupy. They show off the most in drought tolerant or arid landscapes. Boulder or rock framed succulents such as tree aloes and cacti such as the golden barrel create interesting landscapes. When plants are displayed with room around them, it not only enhances their qualities, but leaves room for mature growth as landscape specimens. With a minimum of landscape maintenance and water these develop into incredible gardens.
I hate to advocate for certain plants in landscapes but my favorite enduring plants for trees are: Gingko biloba or Gingko, Olea europaea or Olive, Brahea edulis (the Guadalupe palm), Quercus agrifolia and Q. lobata Coast live and Valley oaks, Afrocarpus gracilior (the fern pine). For shade plants I favor: Aspidistra (the cast iron plant), Clivia miniata (Clivia) and the many Rhaphiolepis that abound now in the industry. Specialty arid climate plants such as Agaves, Cycads, Dasylirion, various tree aloes, Dracena, and Beaucarnia add dramatic interest to even the most eclectic landscapes.
Adapted plants that grow well in our Mediterranean climate and are irrigated appropriately can grow successfully here. Plants from South America Chile/Argentina; from South Africa and from Southern Europe are well adapted to California. Australian native plants are less adapted and thus cannot really be considered enduring here although they certainly are in Australia. Maples adapted to soils and climate of the Eastern United States are not enduring here, but are ubiquitous in eastern states. Climate matched plants from other lands often perform well in California and in some cases and locations become escaped weeds such as Eucalyptus spp. So the best bet for enduring plants is slow growing varieties not easily propagated or able to otherwise escape the garden.
While many new pests that feed on a surprising number of ornamentals plants are upon us in Southern California, we still have enduring plants. These plants are usually pest free or have low occurrence of pests. Less money is spent on pest management and these plants appear less blemished from injury or attack. Their leaves should also be free of mineral defects, either insufficiencies or toxicity. Mineral effects would indicate a lack of adaptation to our soils and thus these plants cannot be termed enduring. While nurseries don't categorize plants in this manner, I think careful plant observation in landscapes can give gardener guidance in the selection of favorite “enduring” plants.