Why do plants flower at different times of the year?

The flowers appears at the times most suited to the production of seed for the continuation of the species. Before seed can develop the flower must be pollinated. This means that the dust-like pollen produced by the stamen of the flower must be transferred to the stigma of the ovary. Pollination is brought about by various means. Most plants are pollinated by insects and, therefore, flower at a time when the insects are active. The flowers may have evolved a particular colour and scent to attract particular varieties of insects.(?s and answers)