Weekend Work: Time to tend to dahlia plants

What to do

New dahlia plants should be in the ground now, well protected against slugs. Thin out the growths of established dahlia plants, leaving perhaps four or five main stems to grow on. Tie the growths to strong stakes. A thick mulch after a storm will help retain the moisture they need.

Take out the dead flowers from lilac bushes and prune out some of the scraggier growths.

Grey-leaved brachyglottis (senecio) is coming into flower now. If you grow it for the leaf rather than the flower, cut out the flower heads now.

Hoe regularly between rows of onions and other veg. If you have water to spare, give it to beans and courgettes, not tomatoes, unless they're in growbags, in which case they'll need regular drinks. Keep pinching out the sideshoots on staked tomatoes.

Make sowings every two weeks of salad crops, radishes and spinach.

What to see

Andrew Bliss is an artist and his garden at 87 St John's Rd, London E17 4JH is nearly all made in pots. The wall art is mostly his own. The garden is open tonight (7.30-10.30pm) and tomorrow (1-5pm), admission £2.50. At Elm Tree Cottage, 85 Croham Rd, South Croydon CR2 7HJ, the style's Mediterranean with olives and figs, phlomis and lavender. Open tomorrow (1-4.30pm), admission £3