Spring, summer and autumn-flowering


As noted in the introduction, flower bulbs are classified into various groups: spring, summer and autumn-flowering. The most familiar, and also the ones most commonly used in privately owned gardens and public green areas are the spring-flowering bulbs: from crocuses to tulips and everything in between. Spring-flowering bulbs not only tolerate the bitter cold of winter, they actually need a period of cold to develop properly. This is due to their original habitats: many spring-flowering bulbs evolved in areas of high elevation in Eastern Europe and Central Asia. They are thus planted from late September until mid-December and will flower the next spring. All spring-flowering bulbs are planted as “dry bulbs”.

With just a few exceptions, summer-flowering bulbs will not survive in the ground through the winter. Again, this is due to their original habitats that are usually located in subtropical or tropical regions. Summer-flowering bulbs are planted starting in late April and will have to be taken from the ground before the first frost. This requires a little more work than what’s involved with the other two groups, but the bounty of colour they provide makes up for it. Most summer-flowering bulbs are planted as “dry bulbs”. In recent years, however, certain kinds such as dahlias, begonias and crocosmias are increasingly becoming available in early spring in the form of potted bulbs ready to plant.

The autumn-flowering bulbs are the smallest group. The only ones actually usable in a variety of situations are the autumn-flowering crocuses, the colchicums, and the cyclamens. These are planted from late July to mid-September and will flower that autumn.

For landscaping purposes, the most commonly used bulbous plants are the spring-flowering bulbs; summer and autumn-flowering bulbs are used to a much lesser degree. For this reason, the situations and examples given here focus on the use of spring-flowering bulbs.