Weekend Work: Times to sow the seeds of perennial plants

What to do

Seeds of perennial plants will now be ripening fast. Some are best sown as soon as they are gathered. Aquilegias, for example, germinate best if sown now in pots or boxes of damp compost standing in the shade. I had some good new aquilegias this season, crosses I suspect between shaggy 'Nora Barlow' and a deep blue granny's bonnet.

Primula seed is also best sown fresh, though, like pansy seed, it germinates most successfully in cool conditions (below). Seed of astrantia, campanula, foxglove, hellebore, hollyhock, honesty and polemonium can all be sown freshly gathered, though not all will be ready yet.

Garlic can be lifted as soon as the tops begin to wither and onions turned down to help the bulbs ripen. Radish and lettuce will not germinate successfully if it is too hot and dry, but earlier sowings of the crunchy cos lettuce 'Romaine Ballon' (Mr Fothergills £1) and the mildew-resistant butterhead 'Clarion' (Mr Fothergills £1.39) may still be providing salads.

Summer pruning of espalier, fan and cordon-trained apple and pear trees needs to be tackled. Long fresh shoots on the main branches should be cut back to three or four leaves above the dorsal cluster. Where spurs have got really nobbly, cut back shoots leaving only one leaf.

Philadelphus and weigela may need thinning. Cut out about a third of the flower stems, close to the base.

What to see

Fergus Garrett, the superb head gardener at Great Dixter, Northiam, East Sussex, is leading two study days next month. In the first, 'Succession Planting in the Mixed Border' (3 August, 10am-4.30pm), he'll use the famous Long Border at Dixter to explain what you need to do to ensure interest for as long a season as possible. 'Exotic Gardening' is the subject on 10 Aug (10am-4.30pm) when Fergus deconstructs the Tropical Garden at Great Dixter and explains how to create the same kind of effects at home. Each day costs £100. To book, call Perry Rodriguez on 01797 252878 or e-mail office@greatdixter. co.uk. For further information visit greatdixter.co.uk.