Ask Mr. Smarty Plants

Philadelphus ernestii (canyon mock orange) is endemic to a small area of the Edwards Plateau, but widely cultivated, which may save it. In fact, it will be on sale at our Wildflower Center Plant Sale this weekend, April 10-11. In terms of whether it will grow in the root zone of a live oak, we simply can't say. Oaks are one of the trees that have allelopathic qualities. This article from Central Texas Tree Experts What is Allelopathy? will give you some insight into the fact that some trees do not permit some plants to compete with them. Unfortunately, we have no way of knowing which plants the oak tree might tolerate under its dripline and which it won't. You will have to make your own decision on whether to experiment with one or two or not take a chance and plant them somewhere else.

From our page on this plant in the Native Plant Database:

Growing Conditions

Water Use: Low , Medium
Light Requirement: Sun , Part Shade
Soil Moisture: Moist , Dry
Drought Tolerance: Medium
Conditions Comments: Almost evergreen plant for shaded and protected locations. Flowers smell like orange blossoms making it an excellent plant near outside living areas. Plant 3 to 4 feet apart in well drained soil. Deer browse this shrub so it must be protected.

From our Native Plant Image Gallery:

Philadelphus ernestii

Philadelphus ernestii