Flowerbeds in public green spaces are particularly suited to seasonal planting: flowering bulbs in spring, followed by annual summer flowers and then perhaps by winter violas. Such locations call for plenty of strong colour.
In an optimal setting, spring-flowering bulbs are planted in layers: early-flowering bulbs such as crocuses in the upper layer and a later-flowering type below them. While the upper layer is in full bloom the lower layer will be steadily pushing up between. Then, when the early flowering types are dying back, the second, more vigorous growth will come along to hide any untidiness. In the ideal case, each of the two layers will be made up of a number of varieties, flowering either simultaneously or successively. A mix like this can deliver six weeks or more of flowering.
Summer flowering bulbs can easily be added to areas planted with annual summer flowers as they should be planted at the same time. Begonias, Canna and dahlia's as well as Ornithogalum, Mirabilis and Tigridia are ready summer-flowering species which can actually transform such an annual bed.