This way the new landscape becomes an exact genetic equivalent of the original, guaranteed to behave just as it did centuries ago at the hands of native peoples or early settlers. If there is residual plant material on the site, it is always better to try and propagate those originals in order to remain as site specific as possible. The same apothecary rose of Spain that grew in the gardens of colonial Mexico and later at the missions of California has not changed. It is still Rosa gallica, and remains nearly identical to its early relatives in the Old World. This plant illustrates how many historic species are still in commercial cultivation and thus make ideal candidates for our gardens.
Considerable study is required to know which varieties are still available for our projects.
Rarely do they appear in the big wholesale grower's catalogs, but are now widely propagated by many small, specialty nurseries. The apothecary rose can only be purchased from specific growers, and unless you are up to date on these obscure sources, you may not feel comfortable specifying such species. The ability to provide the client with a viable source of the material is our responsibility and such tasks should be included when negotiating fees. We all know what happens when contractors fail to do the detective work needed to find obscure plants - they simply make substitutions. There are two reasons why we may substitute plants that look like or are closely related to historic species.