It’s that time of year when you never know what the weather’s going to do, so flexibility is the key in your garden.
We had a very hot spell at the end of June, which caused problems with many plants. We’ve seen several cases of badly scorched leaves and flowers and one customer mentioned that the flowers on their tomato plants had shrivelled up due to the intense heat in their greenhouse, so they’d resorted to covering the plants with brown paper. Keep your greenhouse well ventilated to fend off any heat-related problems.
Never water or spray chemicals onto plants during the day during hot sunny weather – this causes scorching. Instead, water early in the morning or late at night. In a greenhouse, water in the morning rather than late in the day – this gives moisture the chance to evaporate instead of lingering on leaves and causing problems. Keep greenhouse doors and vents open, even at night, to allow good air circulation. Although plants need plenty of fluid in hot weather, some plants don’t take it up so quickly and can quickly become waterlogged – fuchsias are a prime example and are better situated in the shade if possible.
The range of perennials available from garden centres for late summer and early autumn flowering is increasing year on year. Heuchera have lovely coloured foliage all year round from lime green through to copper and bronze and purple shades, many with prominent leaf veins which make a lovely contrast. They’re easy to grow, ideal in sun or semi-shade and are not damaged by slugs and snails. Another pretty flowering herbaceous plant is the monarda (bergamot). These have pretty whorls of pink or scarlet flowers on stiff stems; they usually grow around 1m tall, but we have had varieties in this year which grow to just 30cm.
If you dead-headed your delphiniums and lupins when they finished flowering, you may get a second flush of flowers in September and October. Buying perennials from spring through to autumn will give colour for many months of the year.
Preparing your patch
In the veg patch, harvest onions and potatoes now – lift up onions and allow to dry out where they’ve been growing if the weather is fine, then store. Potatoes should be stored in a cool but frost-free environment – you can buy hessian sacks from your garden centre. Carrots and parsnips can be left in the ground until you’re ready to eat them. Continue to pick runner beans and courgettes on a regular basis, so they don’t become stringy and tough. Any green waste can be put onto the compost heap – use a compost activator such as one by Scotts and Vitax to speed up the composting process, which usually takes about 12 months. Don’t add grass mowing of any lawns that have been treated with weedkiller, though.
Overwintering onions, shallots and broad bean seeds will soon be in stock; plant them as soon as you can and you’ll get an early maturing crop next year. Winter vegetable plants will arrive from the end of July onwards – cabbages, sprouts, broccoli, lettuce – so there’s no excuse for an empty veg plot in the winter!
Choose your hues
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. Once your baskets have finished, why not re-plant for winter colour with vibrant pansies, violas, polyanthus, heathers, ivy… and don’t forget to add a few spring-flowering bulbs for added colour. You can also add small shrubs including gaultherias, leucothoe, skimmias and grasses.
Replant cleared borders with winter pansies, violas, sweet williams and wallflowers. Hopefully our own field-grown wallflowers will be available from the end of September – they give excellent value for money, flowering in the spring with the bulbs and they have a lovely perfume. Spring flowering bulbs should be available over the August Bank Holiday, most can be planted as soon as you get them, but tulips should be planted later – through into November if the weather is mild. When planting in tubs, put several layers of bulbs in first, starting with daffodils then the smaller bulbs and finally plant pansies, violas or wallflowers last. You’ll get a longer flowering period in the spring and full pots.
Buy prepared hyacinth bulbs for Christmas flowering and plant them in bowls with bulb compost by mid-September. Bulb fibre contains charcoal which helps keep the compost ‘sweet’ while the bulbs are in the dark. 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.
Clean out greenhouses before putting in overwintering plants and insulate with bubble wrap. Check over heaters ready for the first frosts. As you bring in plants to over-winter, watch out for vine weevil larvae, especially on fuchsias – there are products available to deal with them.
Enjoy your autumn gardening!