Tender perennials are not native to the UK, so they are unable to survive outside in our cold frosty weather during autumn and winter. However, they have a long and prolific flowering period, usually from June to October, which more than compensates for this. Many tender perennials make good houseplants and greenhouse plants, so they can be kept inside over winter and placed outside during the summer. Plants that grow from tubers (such as Begonias and Dahlias) can be lifted before the first frosts, dried and stored until next season.
Tender perennials are normally raised under glass, in the warm, from seed, tubers or from cuttings. Tender perennials are only planted outside in the UK once all danger of frost has past. Usually at the end of May or early June, depending on latitude and proximity to the gulf stream. As perennials live all-year-round they can be kept as stock plants in a heated greenhouse or conservatory, from which cuttings can be taken each year.
The following selection of tender flowering plants are suitable for domestic gardens in Great Britain (England/Scotland/Ireland).
Most of the popular varieties of tender plants can be purchased as tubers, pot plants or small plug plants from DIY stores and garden centres, usually from March to May. Remember when buying tender perennials that they can still be damaged or killed by cold weather, so they will need protection undercover (in full light), until all chance of frost has past in your area.