What to do
Pick flowers of Iris unguicularis. If you don't get them, the slugs will. The warmth indoors releases the lovely scent. Pull the stems gently, rather than snapping them: they are desperately brittle.
Prune winter shrubs such as witch-hazel (Hamamelis mollis) as soon as they have finished flowering. They are slow-growing creatures and take time to fill a space, so don't be too severe. Cut out any dead bits, thin out congested growth and get rid of any weak, spindly branches.
This month is also the time to cut back dogwoods grown for winter effect. This means varieties of Cornus alba such as 'Westonbirt', with brilliant red stems. The colour is brightest on new growth so the pruning is to persuade the shrub to produce more new stems. Take out a third of the old stems, leaving the rest to make a framework.
What to buy
Potatoes (try blight-resistant 'Sarpo Mira', £2.49 for 10 tubers), onions (£4.49 for 50 'Red Baron'), garlic (£4.99 for two bulbs), blueberries (£16.49 for 'Earliblue'), raspberries (£12.99 for six 'Glen Moy'), gooseberries (£14.99 for 'Invicta'), blackcurrants (£10.99 for 'Ben Connan'), and tayberries (£14.99 for 'Buckingham') all feature glossily in Thompson & Morgan's new spring catalogue. Order now and the plants (or tubers) can be with you this month: 0844 573 1818, thompson-morgan.com