By Bill Ward
Published in The Boerne Star in March 2006
Operation NICE! (Natives Instead of the Common Exotics!) Plant of the Month is Texas mock orange (Philadelphus texensis), a native shrub not typically found in nurseries. A few wholesale nurseries, however, are growing it, and we hope this little shrub will be increasingly available at our local retail nurseries.
Texas mock orange and its almost identical relative, canyon mock orange (P. ernestii), can be used in home landscapes as lowgrowing flowering shrubs in shady locations. These native species are miniature versions of the longpopular non-native mock oranges and their cultivars, which have been grown as ornamentals since at least the early 1800s.
The native mock oranges grow one to three feet high with thin multi-branched limbs and little shiny green elongate leaves. During April and May, the limbs are crowded with white blooms, small but showy and fragrant. The flowers are about three quarters of an inch across and have four white petals around a bright-yellow center of numerous stamens. Jill Nokes (โHow to Grow Native Plants of Texas and the Southwestโ) claims that Texas mock orange โproduces flowers more prolificallyโ than canyon mock orange.
Texas mock orange and canyon mock orange are endemic to the southeastern Edwards Plateau. Texas mock orange occurs only in Bandera, Edwards, Real, and Uvalde Counties, and canyon mock orange is known only in Bandera, Blanco, Comal, Hays, Kendall, and Travis Counties. About the only way to distinguish these two species in the field is by the amount of hairs on the underside of the leaf. Lower leaf surfaces of P. ernestii are covered with short straight hairs, while those of P. texensis are matted with a mix of short straight and long tangled hairs.
Both these species of mock orange are on the Watch List of the Texas Organization for Endangered Species because of their low population numbers and restricted range. Although it has no legal protection at present, collecting mock orange from the wild is highly discouraged. Besides, it doesnโt transplant from the wild very easily.
In their natural habitat, Texas and canyon mock orange grow on boulders and steep walls in moist limestone canyons. Probably one of the densest populations of canyon mock orange is in canyons of the Cibolo Creek just a few miles downstream of Boerne. My nickname for this stretch of Cibolo Creek is Mock Orange Canyon. Here the little shrub is found mostly on the steepest canyon walls, rooted in the minor amount of soil that collects in dissolution holes and fractures in the limestone.
Judging from where Iโve seen mock orange in the wild, it would prefer landscapes with very good drainage and mottled shade or morning sun. Jill Nokes writes that Texas mock orange will adapt to heavier soil as far north as Dallas.
Mock orange apparently is drought tolerant, and I would guess that too much irrigation would kill the locally endemic species. Also Iโd guess that raised beds might enhance cultivation of mock orange.
Iโm not sure if anyone knows for certain whether the two Hill Country species of mock orange have always grown in canyons or whether they were driven there by browsing of goats, sheep, and cattle during the last 150 years. Certainly the more recent over population of deer will keep them within the protection of steep canyons. In my subdivision it would be foolish to plant mock orange without barriers to browsing deer.
Jan Wrede, author of โTrees, Shrubs, and Vines of the Texas Hill Country,โ advocates planting the less-abundant and vanishing native plants in order to help maintain the diversity of Hill Country floral . This is a way to help offset the effects of the decrease in native species diversity brought on by loss of habitat, deer browsing, and invasion of exotics. Texas and canyon mock orange are high on Wredeโs list of priority native plants to use in your landscape. Theyโll make an uncommon and interesting addition to your plants.