What to do in August

What to do in the Garden in August

Many gardeners don’t like August because the best of the summer is over but the lovely colours and scents of an autumn day are not quite here yet. The garden is often looking a bit dry and tired by August, but of course in years with a lot of rain it can also look very lush and green, with not much colour. When rainfall has been extreme, many plants will have put on too much sappy, weak growth and this needs to be trimmed back to give the plant a chance to prepare itself for the winter. When the weather has been wet, slugs and snails will have had a perfect season to wreak havoc amongst almost all the plants in the garden and a quick look through the denser parts of the borders to see if any plants have been eaten beyond regrowth will prevent nasty bald spots next year.


To prevent the August doldrums, you have hopefully planted some late bloomers, such as dahlias, salvias, verbenas and penstemons. These will benefit from some careful dead heading as the month progresses so that they put all of their strength into making more flowers and a stronger root system than into making seed. Perennials really come to the gardener’s aid in August and they mostly come in autumnal colours – perhaps not unsurprisingly – which give a beautifully sunny and coordinated look to any border. Crocosmia looks lovely and when it starts dying back can be split to brighten up a dark corner next year. Red hot pokers often give a nice flush of colour in August and last for ages, but be careful where you plant them because they can attract wasps.



Although many gardeners who concentrate on flowers feel that summer is coming to an end in August, for the vegetable gardener things are in some ways just beginning. You can still sow quite a few things in August and have a reasonable chance of getting a decent crop. Lettuce, spring onions, radish and spinach will all give you something to harvest before winter, but it is a good idea to choose a hardy variety in case of early frosts. Thinking ahead, spring cabbage seeds can be sown where you intend them to mature, to be thinned out later. If you have cauliflower seedlings ready, they can be planted out now.

With luck, you will be harvesting all of your vegetables and fruit in August and getting something back for all your hard work. Even if you have only had a few plants in some tubs or raised beds, there is nothing quite like the taste of something you have grown yourself. Beans and peas are still growing and producing in August and if you are lucky and carefully pinch out the growing tips, you could be harvesting for many more weeks. Tomatoes need to have a lot of attention in August, with side shoots and the tops pinched out to conserve the strength of the plant. Some trusses may need to be reduced and it is vital to watch out for any blossom end rot. This will have been caused by problems earlier in the growing season so can’t be fixed at this late stage, but any damaged fruit can be a magnet for mould, so any showing the blackened and flattened end typical of blossom end rot must be removed. Sadly, it is likely that the whole plant will be affected, as it is caused by a lack of water early in its growth.

 cabbage greyhound


Green manure
If you have harvested a whole bed of potatoes or if you have decided to re-plan a herbaceous border and have stripped out the annuals that have begun to fade, you could refresh and replenish the soil by planting a green manure crop. Not only does it help to keep down weeds in empty soil but it gives it a real boost by giving back the nitrogen to the soil by the bacteria that lives in its roots. There are various different ones you can plant, French beans being perhaps the most surprising but there is also mustard or alfalfa. When it is grown, you can just dig it in.


Pests and bugs
Wasps and other stinging insects can be a nuisance in August as they are at their most numerous. There are various ways to minimise them in the garden by either setting traps – there are many on the market, based on the ‘sugar water’ traps of the Victorians – or by the rather more humane mock wasp nests, which can be hung on the eaves of a shed or in a hedge to convince the wasps that there are already locals in place. Wasps are fiercely territorial and will go elsewhere when they see another nest. With a lot of fruit ripening, wasps are naturally going to be attracted to the garden and so if you have any allergic people around, take care to pick up fallen fruit on a daily basis and dispose of it somewhere safely. This is a good policy anyway; leaving fallen fruit on a lawn will only cause dead patches and attract moulds and fungi. 

Pests love the warm August weather and you will need to keep an eye out for them. With brassicas – cabbages, cauliflower, kohlrabi and the rest – hopefully doing well in the vegetable garden, the cabbage white butterfly has probably been having a ball. You really have to keep an eye out for the caterpillars of this pest, but better still, check for eggs and get rid of them. They will be found under the leaves and if they hatch the caterpillars can strip a cabbage to a sad trellis of leaf ribs in a day. Aphids and blackfly also love August and they can ruin broad beans in particular but in the flower garden can spoil the lovely autumn display of nasturtiums by turning the leaves into a nasty sticky black mess. You don’t have to use pesticides; if the plant is robust enough, you can blast them off with a jet of water. For more delicate plants, add some soap to the watering can and wash them off that way.


August is a good month to have a bit of a look round the garden and see if anything is getting a bit too big for where it is planted. Sometimes a plant which still looks lovely is clearly making plans for garden domination and this is the month to stop it in its tracks before it spreads seeds everywhere and makes matters much worse. If you have a pond, some of the worst offenders are the irises and bulrushes, so act now, before they choke the whole area. It is always worth taking time before planning any major uprooting jobs, to see if there are any sad areas which look a little bare where you could replant some of your thinnings. It is also a good time to have a chat with the neighbours – one man’s pest plant is another man’s prize and so a little swapping is always welcome. Be careful to be honest though about how invasive a plant might be – it is never nice to find your ‘gift’ has taken over a whole plot.


Birds are thinking about the autumn and winter and are fattening up either to fly off on migration or to weather it out here. Your fruit is very tempting and they can strip a tree or bush in no time. If you have a fruit cage, check for rips or tears in it and be very careful that you don’t let a bird in when you are harvesting. They won’t mind being shut in for a while, especially with a nice lot of ripe berries to snack on! Apples and other fruit ripening in August need a lot of water so if the weather turns out to be dry, you will need to make sure that they have plenty. If they don’t get an adequate supply, the fruit will drop or will be very hard and tasteless even when ripe. Some fruits such as some varieties of strawberry and raspberry will have finished their fruiting season and need cutting back. Strawberries can be propagated by runners and perhaps this is a chance to say sorry to your neighbour by landing him with all those Japanese anemone plants last year which are now the dominant species in his border! A nice basket of strawberry plants nicely established for fruiting next year is always a nice surprise for a keen gardener.


Lawns and composting
As in any month there are always the regular tasks. Turning the compost heap is something that should be done regularly through the summer months. There will be lots of trimmings to accommodate on pile and keeping it moving is essential to keep it healthy and not a slimy mess. The lawn needs a lot of care as well; if the weather is dry it is important to keep the blades of the mower set high so that it doesn’t scalp the grass to the soil level. A bald spot now will probably not recover and will attract moss and weeds.


Dont forget to enjoy your garden !
There is something very mellow about a garden in August, with a lovely buttery sun still high in the sky, the swallows still swooping and some late scents in the air from the lavender and some late jasmine. This is not one of those months when you seem to be running around doing jobs here, there and everywhere, but a month for taking stock and enjoying the fruits of your labours – in some cases quite literally. There is nothing quite like sitting back and surveying your garden with a bowl of warm, ripe raspberries to hand.