Do Cultivars Support Biodiversity? By: Keith Nevison, Director of Horticulture and Operations
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ongratulations! Your interest in native plants has piqued and you are inspired to start a garden from scratch this spring. You diligently research native plants from a trusted resource (perhaps Calscape.org or “California Native Plants for the Garden”), selecting for flower color, mature size, drought tolerance, and amount of sun required per day. You feel ready to visit a local nursery and start purchasing from your list. But wait a minute. You arrive to find a jumble of names associated with the plants you’ve planned: ‘De La Mina’ verbena, ‘Bee’s Bliss’ sage, ‘Howard McMinn’ manzanita, ‘Concha’ ceanothus, ‘Wayne Roderick’ seaside daisy. How does one decipher this plant code, and what does it all mean? Fret not — you've stumbled across the world of cultivar names, and I’m here to help you navigate it.
What Is a Cultivar? Before we begin discussing how cultivars factor into a biodiverse garden, we should define cultivars and discuss how they relate to the world of plants. At its basic definition, a cultivar is a botanical contraction of a few words: “cultigen” or “cultivated” and “variety." This neologism, aka new word, was coined in 1923 by the famed Cornell University horticulturist Liberty Hyde Bailey to distinguish between wild plants and those selected, grown, and adapted through human cultivation. The process of selecting plants to become distinct cultivars typically begins in a wholesale nursery by plant breeders or growers who notice a unique plant characteristic that is different than a wild species that it’s closely associated with. A desire to preserve those features is what drives new plant selections and the development of cultivars in the nursery trade, which each year sees more options arrive at your retail nursery. With different nurseries promoting their own cultivars, it’s not unusual to see cultivars rivaling or outnumbering their straightspecies counterparts when shopping for plants at the nursery. From Hybridization to Cross-pollination Okay, we’ve defined cultivar, but how do plants emerge with desirable features that warrant selection in the first place? The process of creating a new plant cultivar can come about in a variety of ways. ‘Roger’s Red’ grape (Vitis ‘Roger’s Red’) is a hybrid that crossed spontaneously between a wild California grape (Vitis californica) and a European common grape/wine grape (Vitis vinifera). It produces beautiful fall color and plump grapes, along with a vigorous growing habit. (Photo: Greg Trainor)
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