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February 2010 — 'Ask the Expert' |
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Q: I have been asked to supply native plant material such as Itea virginica, Clethra alnifolia and Echinacea purpurea. I don’t grow those specific plants but I have suggested substituting with the better cultivars of Itea ‘Henry’s Garnet’, Clethra ‘Hummingbird’ and Echinacea ‘Marcus’. The landscape architect rejected all of these substitutions. Why? Don’t they know that these selections are better and more uniform than the straight species?
A: Ah…the debate of native or cultivar. Is a cultivar of a native plant still a native plant? Well, it depends on the context. If the intent of the design is to establish a self-sustaining population of plants that will produce seedlings and generally take care of itself, then no, the cultivars are not appropriate.
Once a selection has been made and the plant is reproduced vegetatively each plant contains the same genetic information – DNA. They are all clones. Sometimes cultivars are selected because they are sterile and will not produce viable seed. To establish a healthy population genetic diversity is necessary – hence the insistence upon seed grown species.
Q: What is a Nativar? Is it something like a ‘cultivar’?
A: Nativar is a term that I have first heard used by Dr. Alan Armitage from the University of Georgia. Dr. Armitage uses the term to indicate that the plant is a cultivar of a native species. Clethra alnifolia ‘Hummingbird’ is a typical example. Nativars are excellent choices for utilization in a managed landscape such as a garden. They can provide many of the benefits of using a native plant (hardiness, adaptability, food source for birds/butterflies) while still presenting a more refined ‘tailored’ look that many people expect from ornamental plants. |
