Now is the time to sow sweet pea seeds under glass in greenhouses or inside next to well-lit windows.
That is the view of horticulturalists Neil Wormald, who explained in the Times that sweet peas (Lathyrus odoratus) should be germinated under glass while it is still cold and then transplanted outside in mid-spring when the weather turns warmer.
As the plants prefer a long root, Mr Wormald advises that sweet pea tubes should be filled with moist compost with a single seed planted around half an inch below the surface.
Gardeners keen on recycling and saving money can use the cardboard inner from toilet rolls instead of garden centre-bought tubes.
When spring arrives, the tubes should be placed in a "sunny, open, well-drained, humus-rich site", according to the Royal Horticultural Society (RHS).
Alternatively, the RHS advises that sweet peas can be planted in deep pots of seed compost, with seeds placed around an inch apart.