The Role of Cytokinins and Gibberellins on Post-Harvest Longevity of Florists’ Greens

Florists’ greens are a very important element of floral compositions, and their vase life must match that of the flowers, hence this review presents the results of research that has been conducted over the years in order to improve the post-harvest longevity of species that are grown for florists’ greens using growth regulators from groups of gibberellins (GAs) and cytokinins (CKs). Florists’ greens include foliage, the leafy and non-leafy stems of herbaceous plants, trees, bushes, and phylloclades. The post-harvest longevity of florists’ greens is influenced by genetics. Also strongly affected by the growing conditions and the conditions of the transport of the florists’ greens and the conditions when supplying them to markets are also significant. Moreover, florists’ greens are not supplied with growth regulators, which play a critical role in their ageing process. The CKs and GAs are considered to be inhibitors of ageing; however, unfortunately, their content in plant tissues decreases during the progressive ageing process, while the amount of regulators that accelerate ageing increases. International research is focusing on the use of growth regulators in the post-harvest treatment of florists’ greens. Their effectiveness has been shown to depend on the species, the cultivar, the concentration, and the method of application, therefore, there is no ready-made recipe that can be used for all species. The growth regulators from the CK and GA groups are used to condition the florists’ greens. Few studies to date point to the possibility of using topolines (Ts) and ionic liquids in order to extend the post-harvest longevity of florists’ greens. The standard cut flower medium containing 2% sucrose and hydroxyquinoline esters—sulphate or citrate (8HQS and 8HQC)—at a concentration of 200 mg·dm−3, which is used to conditioning, does not have a positive effect on florists’ greens of most species.