Growth and Flowering of Annual and Perennial Landscaping Plants Grown Under Reduced Maintenance for Five Years

Abstract

To study characteristic of ornamental plants used for landscaping, 16 annuals and 24 perennials were sown on Sep. 19, 1996 and grown under reduced maintenance for 5 years. Species studied can be divided into 10 groups according to flowering times, longevity and development of growth areas.
The flowering of groups I~V began the first year after sowing. Species classified in Group I contained 1 annual and 8 perennials, which flowered continuously for 5 years and expanded their growth areas. Group II contained 5 perennials, which were maintained in their initial growth areas. Group III contained 3 annuals, in which the growth areas were decreased slowly. Group IV contained 9 annuals and 1 perennial, which flowered 2 or 3 years before disappearing. Group V contained 2 annuals, which flowered only 1 year. The flowering of group VII~IX started in the second year after sowing. Group VII contained 6 perennials, which were maintained in a confident area. Group VIII contained 2 perennials, in which the growth areas decreased slowly. Group IX contained 1 perennial, which flowered for 3 years before disappearing.