At the time of writing these notes about August in the garden I am faced with a dilemma — whether to write for a usual August or to reflect the very strange year we have had to date. As August fast approaches, when gardeners will usually be worrying about keeping container plants well watered, concerned for their lawns etc, once again huge swathes of our country are under water.
Turning to my gardening bookshelf I quickly closed one book which opens its August gardening tips with: “Weather in August is often the same as July: if July is wet, August is likely to be wet as well.” Let us hope not! Very few summers (fingers crossed) are wholly bad and I hope the predictions of the weather sages will prove to be right, with an August and subsequent autumn months to help us all dry out.
My often-repeated advice is to take time out to sit in and to enjoy the garden, but this really is appropriate for a reasonable August — when the die is largely cast in the ornamental garden and there is just a matter of dead-heading, weeding, cutting flowers for the house. Now really should be the time to enjoy your garden, a time to entertain friends, have a barbecue, or just to laze during what we pray will be balmy days.
For those who cannot entirely relax unless they are doing something in the garden then keep an eagle eye open as you weed for self-sown seedlings that can be allowed to develop or potted up for protection depending on what they are. Most seedlings are difficult to recognise when they first germinate and you need to let them develop additional sets of leaves before you have a better chance of recognition. If in doubt pot them up or leave in situ and keep an eye on them. You can easily pull them up or discard if they prove to be something you do not want. Bear in mind that some self-seeded plants will not entirely resemble the parent plant. Aquilegias are a case in point: cultivated varieties sold in plant centres are often very different to the common columbine from which they are derived and seedlings will usually be common columbines rather than multi-coloured fancies but all the better I say for a true cottage garden effect. Foxgloves seed readily as do opium poppies. You can also intentionally sow seeds from these plants in places of your own choosing by collecting the seeds.
There is one big job to tackle this month if you want to sow or turf a new lawn this autumn. Like almost everything in life, the quality of a lawn reflects the care that went into its preparation. Although a cultivator reduces the toil involved, the best result is achieved by digging with a spade to one spit deep because this gives you the chance to remove perennial weed roots as you go. If the intended site of the lawn is a mass of couch grass, ground elder, and buttercups then spray with a glyphosate weedkiller that kills the plant back to the root but leaves the soil ready to use.
The ground usually will be hard in August but if you find it wet and heavy it is probably a sign that you have a hard layer of soil beneath the top soil that prevents drainage. This has to be broken through and you will need to add about a barrow load of coarse grit per square metre and also dig in manure or fine composted bark.
Once the ground has been dug over leave it for a few weeks to allow weed seeds to germinate so you can hoe them before getting the lawn ready for seed or turf.
Perverse as it may seem (if you have just put a great deal of effort into getting rid of compacted soil known as a “hard pan”) but you now need to tread the soil as you level. The best technique is to tread the soil down with little sideways steps. Rake the soil level as you go and get down to run your eye over the surface to spot hollows and bumps. Once you are certain the levels are right you can start sowing or laying turf in September. Remember that unless you want to spend all your spare time acting as a greenkeeper and you are prepared to keep children and pets off the grass it is best to select a general purpose lawn mixture with rye grass. The really fine lawn mixes require considerable maintenance to keep them looking good.
I found a tip in one of the late Geoff Hamilton’s books that was entirely new to me but I pass it on. Geoff suggested that if you have open packets of half-hardy annuals left over from spring sowing (or like me whole packets unopened because I buy too many) try using them up in August when the (hopefully) high temperatures and long day length will bring them on rapidly for some additional colour in containers. He also advocated taking soft cuttings of ageratum, the dwarf decorative begonias, busy lizzies, petunias and even lobelia by inserting several into small pots to grow on (without thinning) as late flowering pot plants.
Of course you should not spend the entire month of August sipping something cool in a lounger. Get up close and personal to enjoy your plants. Prune back any hooligans that are taking over and keep an eye open for shrubs that offer the harvest of semi-ripe cuttings for propagation. At this time of year it is far better to keep cuttings in pots out of doors provided you protect them from drying out. Many will happily strike in a bed prepared with sharp sand. Cover with a polythene cloche coated with dilute white emulsion paint to shade the cuttings. They should root quickly.
Ever since the Hampton Court Flower Show was recently introduced on television by Alan Titchmarsh with the comment that Henry VIII was only any good at “dead heading” this activity in our garden has been renamed doing some Henry VIII gardening. The object of dead-heading is to prevent plants from setting seed — which of course is their objective in life. By constantly removing dead flower heads before the plant can set seed you extend the flowering period. This is especially true of sweet peas and most of the popular container plants. Indeed I firmly believe that by cutting sweet peas for the house you maintain a more continuous flowering display and a delightful perfume. If you want attractive hips on roses of course then you will have to allow flowers to set seed but only roses such as Rosa rugosa and some of the R. moyesii hybrids have hips worth sacrificing late flowering for.
If August does not continue with the summer monsoon then watering may become necessary. It is particularly important to ensure that camellias that are now producing next year’s buds do not dry out to prevent them dropping their buds. Watering is most essential elsewhere in the garden to maintain yields for runner beans and main crop potatoes. Make sure that celery roots do not dry out and make sure varieties that are trench grown are earthed up to blanch their stems. If you have a greenhouse then you will need to water regularly making sure the compost does not dry out. It is also a good idea to damp down the greenhouse floor each morning to increase the humidity but essential to make sure the greenhouse is well ventilated but do not forget to close the greenhouse up on cool nights.
Plants in small pots and containers will probably need watering every day but if possible leave larger containers for a day or two between soakings. If it becomes necessary to water beds and borders then water thoroughly about twice each week but keep an eye open for any plants showing signs of stress.
If you have not already done so now is a good time to start a compost heap in your garden using perhaps a wooden bin. During the autumn you will produce a lot of garden waste as you prune and clean up in the garden. Start the heap now and you will have grass clippings to mix with coarser green waste as plants die back.
If your lawn is a general purpose turf with rye grass it can probably survive through a dry August after all the rainfall of recent months but do raise the height of the mower so that the grass is less stressed. A quality turf lawn may require watering twice each week if you insist on it retaining an emerald colour but most will recover with autumn rain if the mowing height is raised. If you must water then give a good drenching once or twice in a week rather than watering lightly every day. At least this year you can water with a clear conscience! The new green roof on the garage has benefited from the frequent rainfall to become well established before a drier ??? August and September.
For those really seeking things to do in the garden other than relaxing, here is a summary of August tasks.
Lawns
Apply fertilizer to sites for a new lawn a week before sowing. With an established lawn inspect visually to see which areas need repair and apply weedkillers and fungicides. Get an autumn feed ready to apply next month.
Ornamental garden
Continue to dead-head flowers and treat greenfly on roses if it appears. It is now too late to cut back most herbaceous plants to encourage further flowering but there are plants that are weakened by continued flowering such as anthemis and gaillarda that are best cut back now. Mulch, feed and water sweet peas to extend their season (also removing all dead flower stems).
Now, while the evidence is still present and the memory is fresh is a good time to plan any changes to beds or borders. It is also an ideal time to overhaul a bed that has become weed infested. Remember when choosing new planting that by careful selection it is possible to have interest in an herbaceous border from April through to November.
Do not leave renovation of a greenhouse until the late autumn. Now is the time to replace broken panes so that the greenhouse will not have chilling drafts during the colder months to come. It should be easier to paint or retreat timber greenhouses now than when the timber is wet. Make sure too now that the greenhouse heating works before it is suddenly required when the first night frosts occur.
Take cuttings of fuchsias and pelargoniums as well as semi-ripe cuttings of bay, buddleja, hebe, holly, ivy, lavender, lilac, pieris, rosemary and skimmia. You can also take softwood cuttings of Choisya ternata and Russian vine (Polygonum).
Continue to prune shrubs as soon as they have finished flowering and cut back privet and honeysuckle hedges. Do not cut hedges and topiary after August because there is a risk that any later new growth will be susceptible to frosts.
Fruit
Most soft fruit crops are coming to an end now but loganberries and blackberries will soon be ready to harvest. Pick pears before they are fully ripe by gently lifting and twisting. Treat early ripening varieties of apples in the same way. Now is the time to plant strawberries for a crop next summer. They are ideal plants to grow in a raised bed.
Vegetables
Sow spring cabbage now in ground that has not been fed with manure since last autumn and sow further succession crops of lettuce until mid August. In northern Britain Brussels sprout seeds should be sown now for planting out in October for an early crop next year.
Herbs
Harvest and freeze herbs now for use throughout the winter. Take cuttings of bay, mint, rosemary and sage, protecting them for the first few weeks with a cloche or place them in a pot of sand in a cold frame. Split up chives and collect seeds from dill and fennel. Herbs can also be dried before storing them in airtight earthenware or wooden jars. Only put herbs for immediate use into glass jars.