Quick Answer

The key August garden jobs in the UK are harvesting daily, watering containers and new plantings, cutting formal hedges now nesting has finished, summer-pruning trained apples and pears, taking semi-ripe cuttings, collecting seed, and pruning summer-fruiting raspberries. Stop feeding lawns and shrubs late in the month, order spring bulbs, and prepare for September's lawn renovation.

Written by Jim Fellows

Garden & Outdoor Specialist, Garden-Review.co.uk · Updated August 2026

August is the handover month. The first fortnight still belongs to summer - gluts, watering cans and hedge cutting. By the last week the light has changed, the dew is heavy in the mornings, and everything you do starts to be about autumn instead.

Work with that shift rather than against it. Keep harvesting, get the structural jobs done while the weather is still on your side, and put the groundwork in for September, which is the busiest planting month of the British year.

August at a Glance

Priority job

Harvesting - daily, before crops go over or split.

Best window

Hedge cutting and summer pruning of trained fruit.

Free plants

Semi-ripe cuttings root fastest in August warmth.

Stop doing

Feeding lawns and shrubs after mid-month - soft growth won't harden off.

1. Harvest, Store and Deal With the Glut

August is the month of too much of everything, followed abruptly by not enough. Pick daily and preserve as you go.

Beans and courgettes - every two days without fail. A single marrow left on the plant halts production.
Tomatoes - pick as they colour. From late August, remove the growing tip above the fourth or fifth truss so the plant ripens what it already has.
Onions and shallots - lift when the tops flop and yellow, then dry in the sun for two weeks before storing.
Maincrop potatoes - lift from late August once the haulm dies down. Cure in the dark for a fortnight before bagging.
Early apples and plums - test with the cupped-hand lift-and-twist. If it comes away easily, it is ready.
Sweetcorn - pierce a kernel; milky juice means ready, clear means wait, doughy means you have left it too long.
Herbs - cut and dry or freeze now, while oils are at their strongest.

2. Watering and Holiday Cover

August often brings the driest soil of the year, arriving just as most people go away. Containers are the vulnerable ones - a bed can coast for a week, a hanging basket cannot last two days.

Water early morning or evening, deeply, at the roots.
Group containers in shade before you travel, and stand them in trays of water.
Prioritise new plantings, containers and anything fruiting over established shrubs and lawns.
Top up mulch on beds - 5cm of compost or bark is worth several watering cans a week.
Keep an eye on water butt levels and set diverters correctly before the autumn rain arrives.

Restrictions often run into August. Stored rainwater and watering cans normally stay legal under a temporary use ban - our ban-proof watering kit guide covers butt pumps, drip kits and soaker hoses, and the water butt guide helps you size up before autumn refills them.

3. Pruning Jobs for August

Plant	What to do
Summer raspberries	Cut fruited canes to ground level, tie in this year's new canes for next summer's crop.
Trained apples & pears	Summer-prune cordons, espaliers and fans - shorten new side growth to three leaves above the basal cluster.
Wisteria	Shorten whippy new growth to five or six leaves. The winter prune follows in January.
Rambling roses	Prune once-flowering ramblers after flowering; remove a third of the oldest stems.
Lavender	Trim after flowering into a tidy dome, cutting into soft growth only - never into old bare wood.
Plums, cherries, apricots	Prune now, not in winter - summer pruning avoids silver leaf and bacterial canker infection.
Formal hedges	Main annual cut for box, yew, privet, beech and hornbeam.

Check hedges for nests before cutting. Most UK birds have finished by August, but late broods do happen and damaging an active nest is a criminal offence. Look from both sides, and listen. For longer runs and high hedges, our 2026 cordless hedge trimmer guide compares standard and pole models.

4. Take Cuttings and Collect Seed

Free plants, at the best time of year to make them. Semi-ripe cuttings - this season's growth that has firmed at the base but is still soft at the tip - root fast in August.

Take from: lavender, rosemary, sage, thyme, hebe, penstemon, salvia, pelargonium, fuchsia and box.
Cut 8-10cm shoots in the cool of the morning, strip the lower leaves, and insert around the edge of a pot of gritty compost.
Cover with a clear bag or propagator lid and keep out of direct sun. Most root within four to six weeks.
Collect seed from aquilegia, poppies, nigella, honesty, foxglove, sweet peas and hardy geraniums as pods turn brown and dry.
Dry seed on paper for a week, then store in labelled paper envelopes somewhere cool and dry - never plastic.

5. Lawn Care: Recovery, Not Renovation

August is the wrong month for scarifying, aerating or overseeding - the soil is too dry and seed will not establish. This is the month to keep the lawn ticking over and get everything ready for September, when the real work happens.

Keep the cut high - around 5cm while the weather stays dry.
Do not apply a high-nitrogen summer feed after mid-August. Soft late growth will not harden before frost.
Leave brown patches alone. Dormant grass greens up within a fortnight of proper rain.
Deal with weeds and moss in September, not now - treatments work poorly on drought-stressed turf.
Service the mower towards the end of the month, while you can still see what needs doing. Sharpen the blade, change the oil and clean the deck properly.

A blunt blade is the single most common cause of a lawn that browns off despite watering - our guide to sharpening a mower blade walks through the angle, balancing and safety. If your machine is limping towards retirement, how long lawn mowers last covers repair-versus-replace, and our best cordless mowers for 2026 is where end-of-season deals usually land.

6. Problems to Stay Ahead Of

Problem	Action
Tomato & potato blight	Peak risk in warm, humid August weather. Remove affected leaves at once; cut potato haulms to the ground and leave tubers two weeks before lifting.
Cabbage white caterpillars	Peak numbers now. Net brassicas with fine mesh and check leaf undersides twice a week.
Wasps in tree fruit	Pick damaged fruit promptly and clear windfalls - they are what draws the wasps in.
Powdery mildew	Worst on dry-rooted courgettes, roses and honeysuckle. Water more consistently, mulch, thin congested growth.
Slugs on new sowings	Late-summer populations are high. Protect autumn seedlings from the day they emerge.
Blanket weed in ponds	Twirl out with a stick and leave it on the bank overnight so wildlife can crawl back in.

7. Borders and Containers

Keep deadheading - dahlias, roses, cosmos and bedding will run to October if you stay on top of them.
Feed containers weekly with high-potash feed until early September, then stop.
Cut back tired perennials - hardy geraniums, alchemilla and catmint respond to a hard shear with fresh foliage.
Leave some seedheads standing - alliums, echinacea, sedum and grasses feed birds and carry the winter garden.
Stake tall late perennials before the first autumn gales flatten them.
Plan gaps now. Photograph the border while it is in full growth - by planting time in autumn you will have forgotten where the holes were.

8. Get Ahead for September

Order spring bulbs - daffodils, crocus and alliums are planted from September. Tulips wait until November.
Buy grass seed and autumn lawn feed before the September rush.
Sow biennials and hardy annuals - see our what to plant in August guide for the full list.
Clear and prepare beds as crops finish, then sow a green manure rather than leaving bare soil.
Clean the greenhouse glass late in the month - every percentage point of light matters from September onwards.
Check autumn kit - leaf blowers, scarifiers and pruning tools all get used from next month.

August Jobs: Printable Checklist

Harvest beans, courgettes and tomatoes every couple of days
Lift and dry onions, shallots and maincrop potatoes
Water containers and new plantings deeply, early or late
Cut formal hedges after checking for nests
Summer-prune trained fruit, plums, wisteria and ramblers
Cut out fruited raspberry canes and tie in new ones
Take semi-ripe cuttings of shrubs and tender perennials
Collect and dry seed from annuals and perennials
Keep mowing high; stop feeding the lawn after mid-month
Service the mower ready for autumn
Sow winter salads, biennials and green manures
Order spring bulbs and grass seed

Frequently Asked Questions

Should I feed my lawn in August?

Only in the first half of the month, and only if the grass is actively growing and the soil is moist. After mid-August, switch to an autumn feed high in potassium and phosphates rather than nitrogen - late soft growth will not harden off before the first frosts.

When should I stop feeding tomatoes?

Keep feeding weekly while trusses are still swelling. From late August, pinch out the growing tip above the top truss and taper the feed off - the plant then puts its energy into ripening what is already set rather than producing fruit that will never mature.

Can I cut my hedge in August?

Yes - August is the main cutting month for formal hedges such as box, yew, privet and beech. Check thoroughly for late nests first, and cut on a cool, overcast day to avoid scorching the freshly exposed foliage.

Is August a good time to scarify the lawn?

No - September is far better. August soil is usually too dry for grass seed to germinate reliably, and scarifying opens the turf up at exactly the wrong moment. Do the preparation now and the renovation next month, once rain has returned.

What should I do about tomato blight?

Act immediately. Remove and bin affected leaves and fruit - do not compost them. Improve airflow, water at soil level and never over the foliage. On outdoor potatoes, cut the haulms to the ground and wait a fortnight before lifting so spores on the surface die back rather than infecting the tubers.

Jim's Thoughts

The gardeners who have the best autumns are the ones who treat August as a preparation month rather than a farewell to summer. Cut the hedges while the weather is kind, take your cuttings while the wood is right, get the mower serviced before you need it, and fill every gap on the veg patch as it appears. Do that, and September becomes the most enjoyable month of the year rather than a scramble.

August Gardening Jobs: Your UK Garden Checklist

Key takeaways