Weekend gardener: leave tomatoes to ripen
Edibles
Tomatoes left to ripen on the plant taste a lot better. Continue pulling off laterals and removing some leaves to aid ripening and air circulation.
Dwarf beans, beetroot, broccoli, cabbage, carrots, cauliflower, lettuce, leeks, mesclun, parsnips, radishes, rocket, spinach and silverbeet may all be sown now. But remember to keep the soil damp, and that lettuces at this time of year do best out of full sun.
Prepare bed for sowing onions. Mixing into the soil compost or a general fertiliser and wood ash – if you’ve saved some from your woodburner; If not save some in winter for next year.
Keep berries, lemons and other citrus, grapes and kiwifruit wellwatered as the fruit will be forming now.
Prune raspberries. First establish if yours are primocanes, that is raspberries that fruit in both summer and autumn, or floricanes, which fruit in summer only. Only floricanes should be pruned now by removing about 10cm of the end of canes, to encourage lateral branches that will bear fruit next summer.
Ornamentals
Early-summer bulbs will be arriving in shops and if planted now through until late autumn a longer display should ensue.
To optimise flowering, wisteria is best pruned twice a year – in summer and winter. Pruning now will let more light into the base of young growth which enables ripening of wood and improves flower-bud formation. Trim whippy shoots to five or six leaves.
Powdery mildew
Keep an eye out for this fungal disease prevalent in summer and autumn in dry, warm spells.
This whitish mould mainly on leaves can strike many plants, vegetables, including beans and peas, cucumbers, courgettes and pumpkins; fruit such as apples, blackcurrants, gooseberries and grapes; and among ornamentals, the more susceptible include azaleas and rhododendrons, dahlias, delphiniums, hydrangeas, pansies, phlox, roses, as well as sweet peas.
Fortunately control of it does not require fungicide chemicals, rather head for the pantry and try these sprays – one teaspoon of baking soda to two litres of water (a squirt of detergent will help the mixture stick to the plant), or one part skim milk powder to nine parts water. Another trick is rather than tipping the water out when rinsing used milk bottles, throw the milky water over affected plants. If left untreated powdery mildew is unsightly but generally not fatal to the plant.