Although mock orange might not have visible characteristics of a drought-tolerant plant, its looks belie its hardy constitution. It blooms in early summer, during which the shrub is covered with lovely white flowers that are strongly and sweetly scented. Be sure to site this shrub where it has plenty of room to grow and where its flowers can be appreciated. This plant can become a bit scraggly over time, which can be corrected with judicious pruning shortly after flowering. The selection ‘Cheyenne’, which originated from the Cheyenne High Plains Grassland Research Station, is especially lovely and easily found in nurseries. Littleleaf mock orange (Philadelphus microphyllus A. Gray), native to the southwest (and barely into Wyoming), is a bit less cold hardy but slightly more tolerant to drought.
Water needs: low to moderate
Exposure: full sun to part shade
Availability in nurseries: common
Native range: northwestern U.S. and CA and western Canada
Plant family: Hydrangeaceae