Sow hardy annual flowers in generous drifts straight onto the ground this month, as the soil is now nicely warmed up and they'll germinate and get growing in no time.
Annuals include some of the loveliest of all garden flowers, often self-seeding at the end of the year so you'll have new plants popping up next season too. You'll find lots of seed to choose from in your favourite garden centre: try feathery-petalled love-in-a-mist (Nigella damascena), sky-blue cornflowers (Centaurea cyanus) and vibrant scarlet 'Ladybird' poppies, each petal blotched black at the base.
Prepare the ground well before you start, and water if it's dry so you're sowing into damp soil. Then mark out big, generous 'drifts' on the ground where you want each type of flower to be, using silver sand dribbled out of a drinks bottle.
Within each drift, make shallow drills: this helps you recognise which seedlings are the annuals you've sown, and which are weeds. Then simply sow sparingly along the bottom and cover lightly with more soil. Keep well-watered and you should start to see seedlings within a week. Once they're large enough, thin to their final spacings and you can look forward to a summer full of colour.