It's a little too early to cut back penstemons and other slightly tender plants, but it is an ideal time to trim back winter jasmine to encourage fresh growth for next year's flowers, and reduce summer-flowering viticella clematis back to their lowest buds.Viticella clematis is bred from a Spanish species and tolerates drier conditions so they never suffer from clematis wilt. Their flowers come in a range of blue, purple, red-pink and white. Some varieties have asymmetrical flowers streaked in green, like 'Alba Luxurians'. Others have flat, open flowers and the purple 'Etoile Violette' is always the first to flower.
Double pom-pom forms include the navy 'Mary Rose' (now known as 'Flore Pleno'), and the dusky plum 'Purpurea Plena Elegans'. There are also those with nodding bells, including the frilly, pink-veined lilac 'Betty Corning'. Plant them close to once-flowering roses, or allow them to scramble over shrubs, or climb a trellis.
But don't plant them next to spring-flowering alpina or macropetala clematis. These only need gentle tidying after flowering, and separating the inevitable tangle of mixed stems in order to prune the viticellas is impossible.
