Landscape plants and gardening are an attractive issue for environmental beautification in the area of Ornamental Plant Science. Landscape plant architecture and gardening are an interesting environmental biotechnological phenomenon which makes the land, road, house, office and other occasional place attractive to the growers, visitors, houseowners, farmers and pedestrian as well as increasing the values of the land or place. Bougainvillea, Hibiscus, Allamanda and other ornamental plants were used in this study. Effects of phloem and xylem stresses, thinning of leaves, amino oxaloacetic acid (AOA), sucrose, gibberellic acid, aluminium sulphate, cytokinin and glucose on the growth and development of landscaping plants were investigated. Flower/bract growth, flower size enlargement, longevity and vase life of ornamental flowers were evaluated. Chlorophyll content, carotinoid, fluorescence yield of bougainvillea and hibiscus sp. were found significantly difference at different treatments. Different micro-propagation (tissue culture) techniques and molecular (protein and DNA) biotechnology of bougainvillea, hibiscus and other landscape as well as ornamental plants have been discussed.