How to Properly Control the Blooming Period of Chrysanthemums

The chrysanthemum is a typical short-day plant and under natural conditions it mostly blooms in autumn. Flowering-period regulation means using methods such as light, temperature and pruning to artificially intervene in the processes of flower-bud differentiation and development, so that chrysanthemums open at a predetermined time. This is very widely applied in holiday flower supply, exhibitions and cut-flower production.

For forcing cultivation, shading treatment can be used to shorten the daily sunshine duration, so that autumn chrysanthemums carry out flower-bud differentiation earlier under short-day conditions, thereby blooming earlier. During the shading period, it must be kept continuous and complete, avoiding interference from lights or light leakage, otherwise the plants may still grow according to a long-day response, causing delayed flowering or failure to bloom.

Inhibiting cultivation is the opposite: by supplementing light at night to lengthen the sunshine duration, flower-bud differentiation is postponed, achieving the goal of delaying flowering. In winter and early spring, heat preservation or heating measures can also be combined to maintain a suitable growth temperature, making the flowering schedule more flexible and stable.

Flowering-period regulation cannot be separated from supporting management. Timely pinching can promote branching and unify the time of bud appearance, while removing side buds and side flower buds can concentrate nutrients to supply the main flower. Water and fertilizer must be balanced: before bud appearance, appropriately control water and nitrogen, and after bud appearance, increase the application of phosphorus and potassium fertilizers, which helps the flowers become large and uniform.

A common problem is uneven flowering, mostly caused by inadequate shading, temperature fluctuations or excessively large differences in plant growth vigour. In production, plants should be managed separately according to the light-sensitivity characteristics of the variety, pruning and shading times should be unified, and environmental conditions should be kept stable, so that the whole batch of chrysanthemums opens uniformly and on schedule.