August always has that bittersweet combination of long summer days and a real sense of summer slipping away. August evenings are velvet-rich with golden light as the days draw in, and the month has a fullness, like the aftermath of a delicious meal, that pervades the whole garden. The August borders take on a kind of mature, leonine energy with strong colours made richer by the combination of heat and falling light.
Longmeadow takes on a new suit of clothes. There is a new richness of colour dominated by oranges, burgundies, purple and gold. Every day that passes is a bite out of summer and the movement is towards autumn. Yet the borders gain an intensity as though to counter this.
There used to be a piece of received wisdom that August was somehow a dead month in the garden. Maybe climate change has had an influence but if it ever was true it is certainly not so now. Whereas our July gardens started to feel worn out by drought and heat the August borders take on a kind of muscular energy, full, mature and assured. The sun is lower in the sky and the evenings, by the end of the month, much shorter so my favourite time of day is when the early evening sun hits the rich colours in the borders so that they glow with regal intensity.
August is also the peak of the vegetable year. It is the month of harvest. Gradually, one by one, all the crops are gathered in from the glut of tomatoes – perfect for freezing for sauce deep into winter – to that first ripe corn on the cob or my favourite August dish, a ratatouille made from my own onions, garlic, courgettes, tomatoes, dwarf beans and chilli.
At this time of year it is very common to find that the petals of dahlias are clearly chewed and nibbled, often reducing them to tattered rags and pale imitations of their supposed glory.
The culprits are earwigs that have a distinct penchant for what is – to them at least – a juicy and delicious dahlia flower.
Conventional horticultural advice is to trap the earwigs overnight by placing an upturned pot or a matchbox on a cane by the dahlia and stuffing it with straw. The earwig goes into this at dawn to rest up, thinking it a convenient safe haven but realising that you, the gardener, are about to come along and extract you from your strawy bed before doing something very unpleasant and probably terminal.
But the common earwig, Forficula auricularia, is a fascinating creature. Earwigs certainly do not rely upon the dahlia for their daily diet, being pretty much omnivorous and will eat other insects that gardeners consider as pests. They thrive in mild, damp conditions which makes the UK almost ideal for them but can most readily be found under loose bark or any woody crevice in great clusters – attracted to each other by scent pheromones that they release. The females lay about 30 cream coloured eggs in underground nests in the new year and the nymphs hatch out in April and go through a number of cycles during which time the female will protect and feed them, until they are large enough to foray out on their own.
They seem to like dahlias because in late summer and autumn – when dahlias are at their best – the massed petals of the flower heads provide ideal shelter for them and once ensconced they nibble a little at their surroundings.
What to do in the garden this month:
CUT LONG GRASS
If you have areas of long grass – especially if they are planted with bulbs like daffodils or crocus, they should have been left uncut to at least the beginning of last month to allow flowers to set seed and bulb foliage to die back. But by now all long grass should be cut as short as possible. The aim is to expose areas of bare soil so that fallen flower seeds can make contact and germinate.
This might mean hiring a powerful cutter or using a strimmer – although a scythe still does the job as well as anything. Once the grass is cut it should all be raked up and put onto the compost heap (making sure that it is thoroughly dampened with a hose unless it is a very small amount). It is important to remove all cut grass as otherwise it feeds the soil as it decomposes and this will encourage lush regrowth at the expense of the wild flowers and bulbs. However, as long as the grass cuttings are collected, it may be kept mown short right up until winter.
Dahlias will keep producing new flowers well into autumn as long as they are deadheaded regularly. The easiest way to tell the difference between a spent flower and an emerging bud is by the shape: buds are invariably rounded whereas a spent flower is pointed and cone-shaped. Always cut back to the next side shoot – even if it means taking a long stem – as this will stimulate new flowers and avoid ugly spikes of stem.
And if you do not have dahlias then deadhead anything and everything daily – nothing else is so effective in keeping summer flowers lasting as long as possible.
As August progresses, tomatoes steady ripen, working their way up the growing cordons. From now on the aim should be to develop as much fruit as possible and not encourage much more actual plant growth. A high potash feed such as liquid seaweed or home-made comfrey tea will help and I remove all the leaves around ripening fruit which exposes them to sunlight, increases sugars and speeds up ripening whilst also adding ventilation and reducing the risk of blight or viruses.
As August progresses semi ripe cuttings taken from current season’s wood that has started to harden off are increasingly available and also increasingly likely to root quickly. In principal it is best to take cuttings in the morning whilst the plant is full of moisture but in practise it is something best done as and when you are minded to do it.
Always choose healthy, strong, straight growth free from any flowers or flower buds. Once you have taken material from the plant and placed it in the polythene bag go and pot them up immediately.
Strip off all lower leaves and side shoots so that only an inch or less of foliage remains. Cut the bare stem to size with a sharp knife or secateurs and bury it in a container of very gritty or sandy compost.
Put this somewhere warm and bright but not on a south-facing windowsill as it may scorch. Water it well and then keep it moist with a daily spray from a hand mister to help stop the leaves drying out before new roots have time to form. You will know that the roots have formed when you see fresh new growth. At that point the cuttings can be removed from the pot and potted on individually before planting out next spring.
MAKING NEW STRAWBERRY PLANTS
After the early strawberries finish fruiting – usually the middle of July – they put their energy into producing new plants via runners. These are long shoots with one or more plantlets spaced along their length. As the plantlets touch the soil they put down roots, establish quickly and so the plant regenerates itself. By pinning them to the soil or onto a pot with compost in it and then separating it from the mother plant these can be harvested as new plants that will have more vigour than the parent and keep your stock replenished and refreshed. I dig up and compost the parent plant after four years as their productivity rapidly declines after this and they often accumulate viruses.
By the end of August the rooted plantlets are ready for planting out into a new bed that has had a generous amount of compost added to it as strawberries are greedy feeders (they should always be planted on soil that has not grown strawberries for at least three years to avoid possible viruses). Space these at least 12 inches apart and ideally twice that to allow for maximum growth and productivity. Keep them well watered and mulch with more compost in autumn.
SOWING AUTUMN SALAD CROPS
Sow hardy salad crops such as ‘Rouge d’hiver’ and ‘Winter Density’ lettuce and Corn Salad, Rocket, Land Cress, Purslane, Mizuna and Mibuna. Make one sowing now for harvesting in October and November and another in a month’s time that will crop in the new year if grown under cover. Either sow them into plugs that can be transplanted as seedlings or sow direct in rows. Thin the seedlings as they emerge and keep them weeded and well-watered.
To avoid woody, leggy plants, lavender should be pruned every year. The best time to do this is as soon as the flowers start to fade, which, depending on the variety, can be any time between midsummer and the end of August. But do not wait for the seed heads to form or the flowers to turn brown as you want to allow the maximum amount of time for regrowth before winter.
Cut back hard to a good compact shape but be sure to leave some new shoots on each stem – lavender will often not regrow from bare wood. These new shoots will grow fast and provide an attractive and healthy cover to protect the plant in winter and provide the basis of next year’s display.
Growing your favourite plants from seed is easy and practically without cost. Not only will this give you dozens of free plants for future years but also spares to give or swap with friends and family and August is the time to begin collecting seed from your garden.
Use brown paper envelopes – A5 is the ideal size – and either carefully cut the seed heads and upend them into the envelopes, seed head and all or else place the envelope over the seed head, seal it and then snip the stem off and store it upside down. Label each envelope clearly with the date, name of the plant and, ideally, the position in the garden, and store them in a cool, dry place.
After a week or two the seeds should be dry and can then be sieved, cleaned and stored in sealed packets. For longer term storage, a plastic tub with a tight lid stored in the fridge is ideal.
WATERING CAMELLIAS, AZALEAS AND RHODODENDRONS
Camellias, Azaleas and Rhododendrons form their flower buds in late summer and autumn. In other words the display that they give you next spring is largely determined over the coming weeks. If they are too dry the buds will not form properly and those that are made quite often subsequently drop off in the spring before flowering as a result of dehydration the previous autumn. So give them a good soak – with rainwater if at all possible – especially if they are growing in a container, and do so each week for the next couple of months.