Some summer flowering annuals (bedding annuals) are not fully hardy, so need starting off in the greenhouse. Alternatively you can buy these as plugs (sturdy seedlings) or buy larger plants later in the season. You can also buy hardy annuals as plugs or plants.

Plugs and plants are produced from seed that is sown indoors in February in small pockets of compost (plugs) thinned out and then sold on to gardeners or these plugs are transferred to pots for sale later. Whether they are naturally hardy or half hardy, this method produces tender plants that have to be hardened off by leaving them outside during frost-free periods. Once acclimatised to the colder outdoors, naturally hardy types can be planted out, but the naturally half-hardy types cannot be planted out until frosts have finished.

If you have a greenhouse, some half-hardy annuals are easy to grow from seed, including these:

• Single annual aster (China aster) (Callistephus)
• Dwarf French marigold (single) (Tagetes)
• Night-scented stocks (Matthiola)
• Cosmos (Cosmos)
• Annual sweet William (Dianthus)
• Annual pink (Dianthus)
• Annual phlox (Phlox)

Other half-hardies are often available as plants, including:

• Ageratum (Ageratum),
• Alyssum (Alyssum),
• Petunia (single) (Petunia),
• Tobacco plant (Nicotiana),
• Cherry pie (Heliotropium),
• Snapdragon (Antirrhinum),