Sultry summer days, heat haze, parched grass or torrential storms, the high summer mix. Lammas, on the 1st of August, traditionally celebrates the grain harvest with offerings of bread to the pagan gods. Meadow plants too have ripened seeds and are ready to cut, to be left on the ground to dry until the seeds fall, then raked up and removed to reduce fertility and allow the recovery of the sward for the following year. Hedgerows and trees are full of ripening fruits, berries and nuts; autumn is approaching. Swallows and house martins are beginning to gather in flocks before leaving for their migration to Africa to avoid the European winter.
In dry weather the August garden can look listless. Earlier summer plants are on the wane and those that flower into the autumn may not yet have bloomed, but there are repeat flowering plants and drought tolerant species bringing colour and interest to the fading greens of late summer.
This summer rainfall has been more frequent. Grass, normally brown at this time of year, remains green and the hot spell towards the end of July has helped to bring on autumn plants. This pattern of weather is not the recent norm. Summer has seen heavy flooding in parts of the UK and serious heat waves with wild fires in other parts of Europe. Changing patterns with more extreme and unpredictable weather means it’s important to think about resilience in the garden. Selecting plants that can tolerate both waterlogging and drought, mulching to reduce weed growth and the need for watering, plus adding organic mater to the soil whenever possible to maintain soil structure and fertility.
In the garden
Many ornamental grasses look their best in August, their tall flowering spikes reaching up from a leafy base to form gently swaying translucent curtains. They have an architectural form that remains for most of the year, creating texture, depth and movement in a garden. In late summer the seed heads shimmer in bright light glowing gold, pink and silver in the sun. Stipa gigantia has clumps of grey green leaves, tall stems and oat like, golden seed heads. Pennisetum x advena ‘Rubrum’ with its purple tinged leaves has large, soft, bottlebrush like flowering heads of pink and gold. Molinia caerulea subsp. arundinacea ‘Transparent’ has ribbon like leaves, tall stems and tiny seeds creating a gauzy curtain which dances in the breeze.
There are other late-summer perennials that bring colour to the garden in August. These include the Mediterranean species such as lavender, rosemary, oregano and hyssop that are drought tolerant and thrive in the sun. Many daisy like, prairie plants are also in flower. Vibrant sneezeweed (Helenium) with rich, warm coloured petals and contrasting rounded centres, bright Rudbeckias, many with dark centres and yellow petals that lighten up the borders and the elegant, often drooping, flowers of the coneflower (Echinacea sp). Amongst these the tall and airy purple sprays of the purple top vervain (Verbena bonariensis) and the vivid, trumpet like flowers of monbretia (Crocosmia) and the perfect, deep blue, spiny, spherical flowers of the globe thistle (Echinops). Shrubs in full bloom this month include the large, spires of the butterfly bush (Buddleja); the simple, soft, saucer like flowers of the mallow (Lavatera), and the cloudy plumes on the smoke bush (Cotinus coggygria) above its brilliant deep purple leaves. The vigorous viticella clematis group, flower from July to September, scrambling through shrubs or covering walls and trellises with their rich colours. They are native to Spain and southern Europe so love the sun. Clematis ‘Etoile Violette’ has deep purple flowers, Clematis ‘Madame Julia Correven’ with rich ruby flowers and wine red Clematis ‘Royal Velours’ all bring an abundance of colour.
Other species offer repeat flowering, so it is possible to plan for a succession of plants to flower right through the summer, providing distraction from the gaps as individuals emerge at different rates and naturally begin their annual decline. These late-summer flowers are essential to pollinators and other nectar seekers. Late flying butterflies such as Painted Ladies and Small Tortoiseshells, the Hummingbird Hawk moth, a day flying moth, and dusk flying moths all appreciate the provision of late nectar. Some plants such as the teasel (Dipsacus fullonum) and sunflower (Helianthus annus), have seeds ripening for birds to stock up on energy as we head toward autumn.
With long periods of drought it is still important to keep an eye out for those areas in the garden that even a hard rain may not reach. These rain shadows may be under densely canopied trees or shrubs or against walls and fences, and the plants growing in them may have missed out on any rain that is offered.
Keeping plants well irrigated is essential to their survival and also reduces powdery mildew, which is particularly aggressive with plants that have been allowed to dry out. No matter how hard and long the rains falls, containers need regular irrigation because rain is more likely to drain off the plants’ foliage than into the container and their soil can dry out very fast. Consider reusing grey water from baths or fill a bucket while waiting for the shower water to heat up to save water. And don’t forget birds and mammals, these too need access to water in dry weather.
Harvesting tree fruit
Harvest time for apples and pears depends on the weather, location and cultivar. In general harvest for early varieties of apples and pears in Southern Britain begins at the end of July but some cultivars may not be ready for harvest until late November.
It can be difficult to check for the correct time to harvest tree fruit. Ripeness can be tested by lifting a fruit still attached to the tree and twisting, if the fruit comes away with the stem attached it is likely to be ripe. Other indications include finding numerous windfalls, the changing colour of pipes from pale yellow to brown, or a heightened colouring of the skin. Always handle fruit gently when harvesting to prevent bruising.
Storing apples and pears
In general early cultivars do not store well and need to be used soon after harvest. Mid season varieties can be stored for a few weeks, carefully contained and in a cool, dark space and late cultivars store best. For storing for a long or short period, pick over the fruit and place it in racks or trays either wrapped individually in newspaper, packed in straw or in formed cardboard liners. Fruit needs to be stored somewhere cool but not frosty such as a cellar, shed or garage. Check over fruits regularly to remove any rotting specimens that may affect a neighbour and label and separate different cultivars. Do not store fruits with strong smelling crops such as onions or garlic and do not store near potatoes that release gases that may cause the fruit to rot. Good storing varieties placed in a cool space can last for six months or more. If you have no suitable storage space the fruit can be frozen, dried, juiced and preserved or made into cider or perry.
Propagating strawberry plants from runners
Most strawberries produce runners or stolons, adventitious roots along which new plants begin to grow. If you want to concentrate the plant’s energy into producing fruit the next year it’s best to cut these off, however they can also be used for propagation. Select runners with new growth closest to the mother plant. Either peg the runner down either side of the plantlet with a U-shaped piece of wire or even a stone to encourage root growth into the surrounding ground, or fill small pots with moist, sandy compost and sink them into the ground for the plantlet to root into. This way they will be potted when ready and you won’t need to dig them out of the soil. Water the plantlets well and sever them from the parent plant when well rooted.
Cutting back repeat flowering plants
Many cottage garden plants are repeat flowering. Hardy geraniums such as ‘Rozanne’ and ‘Patricia’, delphiniums, centarea, Salvia nemorosa ‘Caradonna’ and lupins can be cut back after flowering as the stems start to fade. If they are then watered well and given a good liquid feed, a second flush of leaves and flowers will emerge in late summer.
Making your own liquid fertiliser
Making your own liquid fertilizer is cheap and easy. All you need is a bucket, water and vegetable waste, weeds or high nutrient plants like nettles or comfrey. You will be using waste plant material and reducing the environmental costs of chemical fertilizers. Essentially just put the plant material in a bucket, fill the bucket with water and leave to steep for around 4 weeks. The dark liquid can become smelly so leave the bucket outside. Once it is rich and brown pour it onto your plants or crops.
Planting out gaps
If there are gaps in your beds or borders, after other plants have died back you can move tender or greenhouse plants such as perlagoniums, canna lilies or dahlias out into the garden to fill them. Those that were inside should be kept in the shade for a few days to adapt to the heat and higher levels of light before being placed in the sun. Ornamental edibles can also be used. Small brassicas, cabbage, broccoli and kale, oak leaved lettuce or mustard greens can be bought cheaply and grow quickly to fill the gap and in addition provide a crop later in the year.
Massing pots of a splash of colour
If the garden is generally looking faded and dull, a strong splash of colour in one area will help lift it. Mass pots and containers full of flowers to brighten the most heavily used areas. Many tender perennials and summer bedding plants are now being sold off cheaply in garden centres to make way for the new autumn stock. These cheap plants are likely to last up to November if watered, deadheaded and feed through the autumn.
Choosing late summer perennials for insects
As summer draws to an end it is important to provide pollen and nectar for foraging bees, butterflies and moths to build up their resources before cooling temperatures reduce their activity. August is a good time to assess your outside space and plan for next year. Buddleja attracts many butterfly species. Peacocks, small tortoiseshell, painted lady and brimstone are on the wing and all need energy for migration or hibernation. Many of the later flowering species are colourful daisy like ‘prairie’ plants such as Echinacea, Rudbeckia and Aster. These will provide plenty of nectar for bee species. Other plants attractive to pollinators are Echinops, Anchusa, Ballota, Japanese Anemone and Loosestrife. Plant some of these and you will create a haven for pollinators, boosting their reserves for the coming winter.
Leaving seedheads and hips as winter fodder for wildlife
Brown and fading seed heads, orange and red rose hips bring an autumnal feel to the garden. Many create a framework of persistent spires, pods and spikes and seed heads that can give interest well into the winter. In the past it was normal to deadhead and tidy the garden as the summer progressed but if you prefer to garden with nature, the drying stems and fruits can give a further season to your plants and provide a welcome source of food for garden creatures. The fading flowers, ornamental grasses and perennials take on tints of gold, russet and silver, transformed when back lit by the lowering sun and can be especially magical, shinning silvery white, in a frost later in the year.
August is a good month to look out for butterflies flitting through gardens and green spaces enjoying the warmth and seeking nectar. The Big Butterfly Count carries on until the 8th August. You can take part by recording the number of species you see in any given space over a 15 minute period. Details can be found on their website. At this time of year you are most likely to see Red Admirals, Small Whites, Large Whites, Speckled Woods, Tortoiseshells and Peacocks. Moths such as the Hawk Moth and the Jersey Tiger are also on the wing.
Summer drought and waterlogged springs
As weather becomes more unpredictable and extreme there are measures we can take to build resilience in our gardens and green spaces. Waterlogging, particularly in spring when plants begin to respire, can cause plants to die through lack of oxygen. Hot, dry summer weather causes water loss to plants that may then cause them to wilt and die, most plants are not adapted to cope with both extremes. Improving drainage and structure by adding organic matter to soil will help open it up and create air spaces. Using pots and raised beds with drainage at the base or mixing the compost with horticultural grit will open up soil in containers. Creating rain gardens in areas prone to flooding will help with sudden, heavy rainfall. Short lived, self seeding plants such as Columbine Aquiligea vulgaris, Borage Borago officinalis, Purple topped vervain Verbena bonariensis, Foxglove Digitalis purpurea and Red scabious Knautia macedonia are useful as the seed will regrow whenever conditions become viable.
Gardening tasks in August
- Trim hedges after checking for late nesting birds.
- Prune Wisteria by cutting back the lateral and side shoots that have grown since spring to just above the fifth or sixth set of leaves on each stem – or back to the appropriate shoot if the stem has grown to its allotted space.
- Lightly prune lavenders and hebes after flowering.
- Deadhead and summer prune those climbing and rambling roses that do not flower repeatedly and have no ornamental and edible hips.
- Water early flowering shrubs well to ensure good bud development.
- Source spring flowering bulbs such as daffodils, crocus, hyacinth and allium for planting in autumn.
- Sow hardy annuals to overwinter in beds and borders at the end of the month.
- Prune lavender by removing old flowering spikes back into 2-3 cm of green growth whilst maintaining the form of the plant.
- Deadhead plants such as repeat flowering roses and hardy geraniums to encourage further blooms this season.
- Feed pots and other containers to keep them flowering.
- Summer prune restricted fruit forms such as cordons and espaliers to allow sunlight to enhance ripening.
- Harvest ripe apples, pears, plums, late cherries, autumn raspberries, peaches, blackcurrants and blackberries.
- Support the branches of any heavily laden fruit trees.
- Lift and pot strawberry runners.
- Prune summer fruiting raspberries. Cut out all this years fruited stems to the ground and tie in the new green canes.
- Prune the side shoots of grape vines to expose the fruits to the sun.
- Keep birdbaths full and leave out water for any mammals that may visit your garden.
- Leave the seed heads of drying ornamentals and berries in borders, hedges and trees for wildlife.
- Leave some windfall fruit, wildlife will enjoy that too.
- Water plants well at least once a week during periods of dry weather especially recently planted trees and shrubs. Distressed plants can recover after a thorough soaking. Container grown plants are likely to require more watering and be sure to water these so that the water just dribbles out of the bottom of the pot.
- Mow or scythe summer flowering meadows, leave the plants to dry for a few days before collecting. The seed will fall from the plants but removing the rest keeps the soil low in fertility that is what wildflower meadow prefer. If there is any chance of hedgehogs in your meadow area first mow to knee height, check the ground and remove any hedgehogs to a safe place before the final, lower cut.
- Continue to hoe weeds.
- Keep ponds topped up with harvested rainwater. Clear dead foliage from the pond to avoid it building up to a sludge and increasing the fertility levels, this will cause algae to grow and cloud the water.
- Collect seeds for next season. Store seeds in a cool, dry and dark place. Label the containers with the plant name and date of collection.
- Have a general tidy of dead and damaged foliage on plants throughout the garden.
- Keep an eye out for pest and diseases. Check for unusual scarring, stickiness, webbing, curling, lumps or discolouration on stems, leaves and flowers. Remembering to check under the leaves too. Look for the presence of insects, larvae or pupae, which appear static or in abundance. Identify if there is problem with a pest of a disease and remedy as appropriate using organic and biological methods. Bear in mind that many problems with pest and diseases can be prevented and controlled by good garden hygiene, growing and feeding practices. Pests can also provide food for birds, frogs and beneficial insects so only treat if necessary.
- Clean out water butts when empty to remove larval insects and any dirt that has collected.
How to Create a Wildlife Pond
A book to inspire and plan how to build a garden pond for your own outdoor space and a guide to the wildlife it can attract.
Letting in the Wild Edges
A guide to growing and foraging native plants for food and medicinal uses and exploring ways to mark and celebrate the changing seasons.
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Things to see, places to go
Aromatherapy and Herbs for Wellbeing
Saturday 7th August 14.30-17.30
The South London Botanical Institute, 323 Norwood Road, London SE24 9AQ
A Short Course about Amphibians and Wildlife
A short course to learn about London’s native amphibians and wildlife planting. With a site tour of Rockingham Community Allotments.
Saturday 21st August. 12.00-16.00
Rockingham Community Allotments, Falmouth Road, London SE1 4JN