Fill gaps in your borders as they become obvious among newly-emerging spring growth. With the worst of winter over, it's a good time for damage assessment – inevitably you'll find some plants haven't pulled through the cold weather, either because they've succumbed to chilly wet soil (a more common cause of plant loss than cold alone), snow breakages or pest damage.
Don't worry: it's a good excuse to plant some more! Be careful about replacing like for like: roses in particular tend to suffer from 'replant disease', with new plants failing to grow well in a spot where the same plant has grown before. Nobody knows exactly what causes this, but it's easily avoided simply by planting your new rose in a different spot in the garden and replacing the old one with an alternative plant instead.
If you're not sure what to plant, pop down to our garden centre here in Lymington, where our friendly and knowledgeable staff will be happy to help you choose. We've got a huge selection of in-flower perennials, shrubs and trees available for planting right now, so come along and see what catches your eye: soon you won't even remember that gap existed.