Although there are very few true biennials such as our native Foxglove (Digitalis), most are actually short-lived perennials that perform much better when grown as a biennial plant. Usually seed is sown and germinated in summer and the plants are grown-on over-winter, ready for flowering the next year. Hence the term biennial, which literally means "every two years".
Because the plants are hardy and already mature by spring they usually flower much earlier. This makes them great companions for spring flowering bulbs. The main drawback is that they take up much needed space in late summer, when other late flowering plants could be more useful. However, to overcome this you can simply buy trays of pre-grown biennials from a garden centre, ready for planting out in early spring. Others, such as wallflowers, can also be purchased as bare root plants in early autumn.
The following selection of biennials are suitable for most domestic gardens in Great Britain (England/Scotland/Ireland):
Forget me not