Our gardening expert Ann Winwood says some September sunshine will keep our gardens blooming.
Summer is over but that doesn’t mean an end to the flowering season. Which is great news for established gardeners and those who have nurtured a new passion for gardening these past few months. When we all went into lockdown there was a boom in gardening as people discovered its therapeutic benefits. So, fingers crossed we shall have some warm spells which will make being outdoors especially enjoyable and which will be perfect for perennials. With such an extensive range of herbaceous perennials to choose from including foxgloves, delphiniums and lupins alongside the newer plants of perennial salvia, gaura and heuchera, our borders can still be a blaze of colour at this time of year. This is a busy period for gardeners, too, with plenty of jobs needing to be done, from fruit picking to replanting.
Summer baskets and tubs should still be looking good 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 deadhead 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.
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 limit 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 too.
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.
Deadhead roses, trimming back any very long growths. Remove any foliage with rust or blackspot, making sure you dispose of it rather than putting it 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 about 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.
Keeping on top of those essential tasks this season will ensure your garden continues to flourish and bring joy for many months to come.
Happy gardening and stay safe.
This issue’s tips are provided by Ann Winwood of Lealans Garden Centre, Shipley.