by John Hosford
August is one of the most rewarding months in the gardening calendar, with borders, containers and vegetable plots all reaching their peak. This year, we have experienced some of the warmest weather on record over the past few weeks, making careful attention to watering more important than ever.
Water thoroughly and regularly during prolonged dry spells, aiming to water early in the morning or later in the evening when temperatures are cooler. Avoid watering during the hottest part of the day, as much of the moisture will simply evaporate before reaching the roots. Direct water to the base of plants rather than onto flowers and foliage, helping to reduce the risk of disease while ensuring the moisture reaches where it is needed most.
Plants growing in containers dry out particularly quickly during warm weather and should continue to receive regular liquid feeds throughout the month. An organic seaweed-based fertiliser is an excellent choice, promoting healthy growth, strong root development and prolonged flowering.
Regular deadheading remains one of the most important summer maintenance jobs. Removing faded flowers keeps plants looking tidy and encourages them to direct their energy into producing fresh blooms, ensuring colourful displays continue well into the autumn.
Dahlias are undoubtedly among the stars of the August garden. With regular watering, feeding and deadheading they will continue producing magnificent flowers until the arrival of the first autumn frosts. Few plants can rival dahlias for the sheer diversity of colour, flower shape and size available.
Gardeners can choose from elegant single-flowered varieties as well as richly double blooms, while the different groups include dinner plate, cactus, pompon, decorative and bedding dahlias. One particularly outstanding variety is ‘Bishop of Llandaff’, whose rich copper-coloured foliage provides a striking contrast to its vivid scarlet-red flowers.
Birds: During prolonged periods of hot, dry weather it is essential to provide birds with an adequate supply of fresh, clean water for both drinking and bathing. Refill bird baths regularly to ensure the water remains cool and hygienic.
Roses: Rambling roses should be pruned immediately after flowering to encourage healthy new growth for next season. Continue deadheading repeat-flowering roses throughout the garden and remove unwanted side shoots as soon as they appear. Container-grown roses benefit greatly from a weekly liquid feed, while recently planted roses should receive generous watering during dry spells. As with all plants, keep water away from the flowers and foliage wherever possible.
Take cuttings: August is an excellent month for propagating many tender perennials. Healthy cuttings can be taken from pelargoniums, fuchsias, salvias and lemon verbena to provide beautiful plants for next year’s garden. Keep the young plants in a frost-free greenhouse throughout the winter and inspect them regularly for signs of pest damage.
Collect seed: Many annuals and perennials will now be producing ripening seed. Collect seed from your favourite plants while it is fully mature and dry, storing it in clearly labelled packets or containers with waterproof labels for future sowing.
Fruit garden: Plant new strawberry runners into clean ground that has not recently grown strawberries, helping to minimise the build-up of soil-borne pests and diseases. Complete the summer pruning of apples and pears during the month to maintain healthy trees and encourage quality fruit production.
Weeding: Keeping on top of weeds is essential throughout August. Weeds compete with ornamental and edible plants for both moisture and nutrients at a time when water is already in short supply. Hoeing remains one of the most effective methods of control, particularly during long periods of settled weather. Choose a warm, dry day – ideally with a drying breeze – and hoe early in the morning, allowing uprooted weeds every opportunity to wither in the sunshine.
Bulbs for autumn planting and spring colour: Autumn is not far away, making this the perfect time to begin planning next spring’s displays. Autumn and spring flowering cyclamen, together with colchicums, should be planted without delay as bulbs left unplanted for too long can begin to shrivel.
Garden centres will soon be well stocked with spring-flowering bulbs including dwarf iris, narcissi, crocus, hyacinths, anemones, fritillarias and ornamental alliums.
Hyacinths can also be planted now for colourful Christmas displays indoors. For the most effective results, plant a single variety and colour in each container, placing the bulbs close together, almost shoulder to shoulder. Where containers lack drainage holes, use bulb fibre, which provides excellent drainage while keeping the growing medium fresh and healthy. Other excellent bulbs for early indoor colour include amaryllis, freesias and fragrant narcissi such as ‘Paperwhite’ and ‘Grand Soleil d’Or’.
Tulip bulbs will also begin appearing in garden centres this month. It is well worth choosing your favourites early while the widest selection is available. However, tulips are best planted later, during November or December, so store them in a cool, dry place in wooden slatted trays until planting time.
Wisteria can be pruned during August to keep vigorous growth under control and encourage better flowering next spring.
Vegetable garden: Sweetcorn should be harvested as the cobs ripen, while courgettes are at their very best when picked young at around 15 centimetres in length. Allowing them to become oversized reduces both flavour and tenderness.
Continue harvesting cabbage, cauliflower, broccoli and kohlrabi as they mature. Keep a careful watch for caterpillar damage and treat promptly where necessary. Rabbits and pigeons can also cause considerable damage, particularly to brassicas, so effective protection should remain in place.
Providing colour now: August gardens can be filled with colour from an outstanding range of reliable flowering plants.
Cosmos produces masses of delicate flowers in shades of white and pink above attractive feathery foliage and continues flowering for many weeks.
Osteospermum is an excellent sun-loving perennial, thriving in warm, well-drained positions and performing particularly well in coastal gardens.
Hydrangeas continue flowering from late summer into autumn. During prolonged dry weather they require deep, thorough watering followed by a generous mulch to help conserve soil moisture.
Begonias provide continuous displays of vibrant flowers well into autumn and are particularly valuable in containers and bedding displays.
Penstemon ‘Garnet’ remains one of the finest penstemons available, combining exceptional flowering with excellent winter hardiness.
Salvias are available in an impressive range of colours and flower continuously into autumn, performing equally well in borders and containers.
Sweet peas remain one of the garden’s finest cut flowers, offering a wonderful fragrance together with a remarkable range of colours. Regular cutting encourages continuous flowering throughout the season. Weekly feeding with a seaweed-based liquid fertiliser will help maintain vigorous growth and abundant blooms.
‘Euryops pectinatus’ is a cheerful, sun-loving half-hardy perennial producing bright yellow daisy flowers almost continuously from April until November. It is especially well suited to coastal gardens.
Fuchsias are invaluable for beds and borders, often flowering from May until late November. Continue monitoring plants for signs of rust and downy mildew throughout the season.
Pelargoniums, often referred to as geraniums, also provide a remarkably long flowering season. Gardeners looking for something a little different should consider the beautiful rosebud varieties.
Verbena offers attractive shades of pink, red, white and lavender, making it one of the finest choices for containers and hanging baskets, with flowers continuing well into autumn.
With regular maintenance, careful watering and timely feeding, August rewards gardeners with some of the finest displays of the entire gardening year while also providing the opportunity to prepare for the seasons ahead.
