U.S. species, is sometimes preferred in the Deep South over/, crenata 

 because it is less susceptible to spider mites. 



Before the 1930's only a few selections (= cultivars) of/, crenata were 

 known. Now more than 500 cultivars have been named and introduced. 

 Most cultivars have been obtained as seedling selections by the nursery 

 industry, but some have been from mutation propagations. Only a few 

 have been selected directly from wild habitats. This selection process 

 differs from that of/, opaca, whose cultivars were mostly discovered 

 originally as wild-occurring plants and were subsequently named, 

 propagated, and distributed. 



Nursery professionals have discovered that seedling populations of 

 /. crenata vary extensively in size and shape of leaves, in growth habits, 

 and in growth rates. Such variations have led to choosing selections with 

 improved landscape utility and nursery productivity. Most cultivars in 

 commerce today represent the finest selections from among literally 

 hundreds of thousands of seedlings. By far, 'CONVEXA' has been the 

 most popular cultivar, and as a seed parent, it has yielded progeny with an 

 outstanding array of shapes and textures. A limited number of dwarf, 

 small-leaved, and variegated clones have arisen as chance mutations. 



Because of its wide use and ease of culture (including ease of 

 propagation), /. crenata is one of the most popular test plants for research 

 on the production of container-grown nursery crops. From this research, 

 more is known about the response of/, crenata to soil mixes, mineral 

 nutrition, and pesticides than for any other container-grown nursery crop 

 in the United States. 



Despite the popularity of/, crenata as a landscape plant, the nongardening 

 public does not often recognize it as a holly. It is generally seen as a shrub 

 having small, nonspiny leaves and small black fruits. In contrast, holly is 

 traditionally envisioned in western culture as a tree or shrub that has spiny 

 leaves and red fruit. Plant hybridizers have attempted to develop an 

 /. crenata with red fruit. Such fruit would greatly enhance the public 

 image and broaden the versatility of this species. Many attempts have been 

 made and some interspecific hybrid combinations have been achieved 

 between /. crenata and red-fruited species of Ilex; but to date, satisfactory 

 red-fruited hybrids have not been produced. 



