Gardening Jobs for August

Just like your flowers and crops, gardening jobs for August are abundant. There’s lots to do in this busy month, from getting the most out of your beds and borders to making more fruit and helping your kitchen garden thrive.

In this comprehensive guide we’ll talk you through all the gardening tasks for August and how to do them, so you can enjoy your garden at its best.

What to Do in the Garden in August

There are plenty of gardening jobs to be getting on with this month. Here’s what to do in each area of your garden.

Grow More Fruit

If you want more strawberries, we have good news: they’re very easy to make more of. Pot uprooted baby plants (aka runners), cut the stem between these and the mother plant, and remove it gently from the soil with a hand fork. Get rid of any dead leaves and pot into a small compost-filled container. 

When it comes to apples and pears, prune cordon, espalier and fan-trained apple and pear trees. Begin this garden task by seeking out this season’s shoots and cutting any that are around 20cm and growing from a side branch, back to just one leaf. When new leaves appear, prune them back to three leaves.

Order new trees, bushes, and cane fruit so they’re ready to be planted in the autumn.

Stop any brown rot fungal disease spreading to healthy apples and plums on trees by picking off any that have rings of white spores or soft brown patches on the skin. Make sure you put these in the bin rather than the compost pile to avoid the disease spreading to new plants in future via the compost. 

Beds and Borders

Dry weather may make life difficult for some border plants, so give them a hand by spreading mulch thickly on bare patches of soil to keep moisture in. A 10cm layer of compost, leaf mould or well-rotted manure will help moisture stay in the soil for longer. Be sure to water the soil before adding mulch, or spread it on after a good downpour. 

Control leaf disfiguring powdery mildew on Michaelmas daisies by dosing with a copper-based fungicide spray. Repeat in two weeks’ time.

Give a new lease of life to bearded iris. When several years have passed, the middle of clumps can die, leaving the irises reticent to bloom. Prise them from the earth with a fork and divide the outer sections with a knife. Cut straight across the leaves, 15cm from the roots, and replant 15cm apart.

Prevent top-heavy, late-flowering perennials from being pushed over in strong rain or wind by providing the right support. Surround dahlias, asters and helianthus with four canes, tie some twine to one of them and wrap it around the others so as to enclose the plants in the middle. Make sure the twine is tied tightly to prevent the plants from flopping over. 

Plan for September and October by planting colchicums (aka autumn crocus) in borders, 10cm deep in a sunny area. Their funnel-shaped flowers will give you subtle pops of colour during these cooler months. 

Trees and Shrubs

Trim evergreen hedges so they look neat throughout the winter months. In summer, box, privet, laurel, and other hedges will have plenty of growth, which means a tidy finish ends up looking somewhat less than neat. Use a hedge trimmer or hand shears to flatten the top of the hedge and then cut the sides. Leave the top slimmer than the base so that light can reach all sides. Read our guide on how to trim hedges in your garden to find out more. 

Trim lavenders lightly when flowers start to look past their best, removing any dead flower heads. Prune more thoroughly in early spring, removing around 5cm.

Colourful clematis flowers are blooming nicely now but are prone to clematis wilt disease. Avoid issues with this by planting new clematis deeply, a good 10cm beneath the level it was in the pot. 

If not kept in check, wisteria will grow beyond its given space and produce poorer flowers. Tie any stems to fill gaps on walls or trellis and, to bring about a great display next year, cut back this season’s whippy shoots to five or six leaves. Buds will then form more readily. 

In the Kitchen Garden

For succulent greenhouse-grown cucumbers, pinch out the uppermost shoot when it reaches the top of its support and cut down side shoots until two leaves remain beyond each growing fruit. 

Help squashes ripen faster by cutting off any large leaves that prevent the sun from reaching the developing veg. 

Pull up onions when leaves have withered or gone yellow-brown in colour. If it’s not raining they can be left outside on the soil for a couple of weeks to dry, but if conditions are wet, bring them inside and store in wooden fruit crates. 

Blossom end rot can blight tomatoes, so keep an eye out for black, flat, hard patches on the bottom of the fruits. This common problem is caused by a lack of calcium, which is found in water, but can easily be remedied for future fruits by watering every day, or even a couple of times, when conditions are hot and dry. 

Sow seeds for overwintering salad onions, Japanese onions, spring cabbage, turnips, and carrots in your vegetable patch or allotment. 

Keep the courgettes coming by picking young crops frequently, when they’re around 10cm long. This will encourage more to grow and prevent them from turning tough. 

Have spinach ready to harvest at the end of September by sowing seeds of ‘Scenic’, ‘Toscane’ or ‘Tornado’ now. Sow them 2.5cm deep in rows and thin to 7.5cm apart once they’ve started to appear. 

Create a long-lasting supply of parsley from December to summer by sowing seeds now. Fill a shallow, 20cm pot with compost and sow thinly over the surface. Cover with a 1cm layer of compost, water and put in a cold frame or a sheltered spot. Seedlings will start peeping through within a month.

Additional Gardening Jobs for August…

Compost heaps can slow right down and stop when it’s hot and dry, so make sure yours keeps rotting by watering it now and then to keep it moist, and turning it with a fork to introduce air. If it doesn’t have a lid, put a sheet of cardboard or piece of old carpet over the top to trap in moisture and heat. Read our guide on how to make compost for more on this topic. 

Birth baths can quickly dry up when temperatures rise, so top them up frequently.

When the weather starts to turn a bit cooler, shut greenhouse vents, doors and windows after dusk to retain heat overnight. Open them up in the morning so as to avoid a build-up of heat gained during daylight hours.

Once you’ve finished your garden jobs for August, you can relax in the knowledge that your garden’s looking its best and will carry on delivering in the coming months, whether it’s with gorgeous floral displays or bountiful crops. Remember to come back next month to read about your next round of garden tasks, but for now, enjoy!