Our gardening expert Ann Winwood is hoping summer lingers on…
If we get a nice spell of weather through August and into the beginning of September, the flowering season of summer bedding and perennials will continue into early autumn. The range of new varieties of tried and tested herbaceous perennials has expanded quickly over the last few years with the introduction of new foxgloves, delphiniums and lupins alongside the newer plants of perennial salvia, gaura and heuchera – they make a cost-effective alternative to summer bedding. Buying perennials from spring through to autumn will give colour for many months of the year.
Summer baskets and tubs should still be in their prime through September and possibly into October if we don’t get any early frosts, but as the nights draw in and the weather gets cooler, they’ll begin to fade. Continue to dead-head and feed regularly to encourage a late show of colour.
Once your baskets have been emptied, why not replant for winter colour? There’s plenty to choose from – pansies, violas, polyanthus, heathers, ivies and don’t forget to add a few spring flowering bulbs for added colour. Most garden centres sell smaller-sized shrubs that are suitable for tubs and baskets and can then be planted out in the garden next spring. These include gaultherias, leucothoe, skimmias and grasses.
Once borders have been cleared of summer bedding, you can replant with winter pansies, violas, sweet williams and wallflowers. Hopefully if the weather has been moist we’ll have some of our own field grown wallflowers available from the end of September – they give excellent value for money- flowering in the spring with the bulbs.
Harvest onions and potatoes now – lift up onions and allow to dry out where they’ve been growing if the weather is fine, before storing. Potatoes should be stored in a cool but frost-free environment. Hessian sacks available from garden centres are ideal for this purpose. Continue to pick runner beans and courgettes on a regular basis so they don’t become stringy. Pick any remaining tomatoes before the first frosts and ripen on the windowsill or use for green chutney.
A common occurrence on tomatoes seems to be blossom end rot – a brown leathery patch at the base of fruits. This is a physiological disorder rather than a disease or pest and can be worse during days of high humidity which limits the amount of water taken up by the plant roots. It is also encouraged by calcium deficiency; while most composts don’t lack calcium, they do need regular watering to enable it to be taken up by the roots and then to the fruit. If water uptake becomes limited, calcium uptake can become limited.
Make sure plants are watered several times a day in very hot weather, give good ventilation and ideally give a foliar spray of calcium.
Pick early apples and pears as they become ripe. Eat the earlier varieties straight away, storing later ripening ones for later use.
Cover autumn-fruiting raspberries against birds. The old fruiting canes can be pruned out during the winter months as the autumn varieties fruit on the new season’s growth each year.
Dead-head roses, trimming back any very long growths. Remove any foliage with rust or blackspot, making sure you dispose of it rather than putting on the compost heap. Remember to clean up any debris under rose bushes as blackspot will overwinter ready to infect bushes again next year.
Clean out greenhouses before putting in overwintering plants, and insulate with bubble wrap. Check heaters ready for the first frosts. As you bring in plants to overwinter, watch out for vine weevil larvae, especially on fuchsias. If you do see signs of them, drench the compost with one of the chemicals available for their control. Encouraging hedgehogs in your garden is another good control, and there are also nematodes on the market, which are best used in September.
Buy prepared hyacinth bulbs for Christmas flowering and plant them in bowls with bulb compost by mid-September. Give them a drink and put in a cool, dark place, bringing gradually into the light and warmth once the shoots are approx 3cm high. Overwintering onions, shallots and broad beans will soon be in stock; plant them as soon as you can and you’ll get an early maturing crop next year.