This popular ornamental shrub is generally included by North American authors within a broad concept of D. scabra Thunb. However, Brock (i2022) has shown that scabra sensu stricto is unknown as a naturalized species. According to W and Brock, further study of naturalized North American plants is desirable to determine if some are referable to scabra. At least ten species have been described within this species-complex. In Ky., crenata has become locally naturalized at Natural Bridge State Park and nearby in POWE (KY). An initial attempt at eradication here in the 1990s was not followed up and the plants are still abundant. Several other species and cultivars of Deutzia are used in horticulture, especially D. gracilis Sieb. & Zucc., but there are no records of naturalization in Ky.