August brings us to the very heart of the British summer. The garden is at its richest and most productive — borders glow with colour, the kitchen garden overflows with crops, and long warm evenings invite us to linger outside long after the sun has dipped below the horizon. After the extended extreme heatwaves of June and July, August calls for a slightly different approach: consistent maintenance to keep standards high, wise watering in dry spells, and the first quiet preparations for the season to come.
August will probably have extensive heat as well but with sunshine that perfectly suits the Mediterranean garden — those heat-loving plants that transport you in spirit to a sun-drenched terrace in Tuscany or Provence. Whether you are nurturing an olive tree on your patio or tending a pot of lemon-scented citrus in the conservatory, this is their moment to shine. Below are our exclusive Heritage Gardens gardening tips and advice for August 2026, provided by our own garden expert.
☀️ The August Garden — What to Expect
August in the UK can bring some of the warmest and driest conditions of the year, with temperatures across England regularly reaching 22°C–28°C or higher during sunny spells. The days, while still long, are noticeably shorter than at midsummer, and there is already a whisper of early morning freshness that signals the approach of autumn. Rainfall can be unpredictable — some Augusts are gloriously settled, others punctuated by thundery showers. In either case, water management is the defining garden task of the month with much of the country in drought status.
Keep a close eye on both drought stress and if there are heavy downpours, slug and disease activity, which can flare up rapidly in warm, humid conditions.
🌿 Lawns
- All lawns will be brown now but they will come back — In prolonged dry spells, grass naturally goes dormant and turns yellow or brown. This is a protective mechanism, not death. Once rain returns, it will green up surprisingly quickly. Resist the urge to water the entire lawn — it is rarely necessary and uses a great deal of water.
- Raise the mower blades — If you are mowing, raise the cutting height slightly in dry periods. Longer grass shades the soil, retains moisture and copes better with heat stress. Never cut more than one-third of the grass blade at once.
- Avoid feeding in drought — Do not apply nitrogen-rich lawn fertiliser in August if conditions are dry. Wait until autumn when the soil is moist and temperatures have cooled before applying any autumn lawn treatment.
- Repair worn patches — August is a good time to assess the lawn and make note of areas that need attention — worn patches, compaction, moss or weed problems can all be addressed properly in September with an autumn renovation programme.
🌸 Borders, Flowers & Bedding Plants
- Deadheading — continue relentlessly — This remains the most valuable border task of high summer. Remove spent blooms from roses, dahlias, rudbeckia, echinaceas, petunias and all summer bedding every few days to keep plants flowering as long as possible. Let just one or two blooms set seed and the whole plant often stops producing new flowers.
- Dahlias — Dahlias hit their magnificent stride this month. Feed weekly with a high-potash liquid fertiliser such as tomato feed, ensure they have adequate water at the roots, and tie in tall stems to canes as they grow to protect against wind damage.
- Roses — second flush — Many repeat-flowering roses will be producing their second flush of bloom this month. Deadhead faded blooms promptly and give a final summer feed with a specialist rose fertiliser to encourage this second display. Watch for blackspot and mildew, which can worsen in humid spells — treat promptly if needed.
- Taking cuttings — August is an excellent month for taking semi-ripe cuttings of shrubs, including lavender, rosemary, fuchsia, pelargoniums and many other plants. These root readily at this time of year and will provide free plants for next season.
- Sweet peas — Keep picking sweet peas regularly and remove any seed pods that are forming. Pinch out growing tips if plants become straggly to encourage new bushy growth and further flowering.
- Late colour gaps — If any gaps appear in borders, pot-grown rudbeckia, echinacea, agastache and hardy fuchsias can be planted now and will provide colour through to the frosts.
🌳 Trees, Shrubs & Climbers
- Wisteria — second summer prune — Wisteria requires its second pruning of the summer now, cutting back all the long whippy new shoots produced since the first prune in June to around five or six leaves from the main woody framework. This is crucial to building up the flower buds that will give next spring’s spectacular display.
- Rambling roses — Once ramblers have finished flowering, they can be pruned now. Cut out as many of the oldest, flowered stems as you can manage at the base and tie in the vigorous new growth to replace them.
- Hedges — Give formal hedges (box, yew, beech, hornbeam, privet) a final trim now. Trimming in August produces a neat finish that holds well through autumn and into winter.
- New trees and shrubs — Any trees and shrubs planted in spring will need generous, regular watering throughout August. A deep soak once or twice a week is far better than a light daily sprinkle. A mulch of garden compost or bark chippings around the base will help to retain soil moisture considerably.
- Lavender — Once lavender has finished flowering, trim the plants lightly with shears to remove the faded flower stalks and the top few centimetres of foliage. Do not cut back hard into old wood. This keeps plants bushy, compact and productive for years to come.
🥦 The Kitchen Garden — Vegetables, Fruit & Herbs
- Harvest, harvest, harvest — August is peak harvest season. French beans, runner beans, courgettes, cucumbers, tomatoes, sweetcorn and salad leaves will all be cropping abundantly. Pick regularly — courgettes in particular will turn into marrows if left on the plant even for a few days in warm weather.
- Tomatoes — Feed weekly with a high-potash tomato feed, water consistently (irregular watering causes blossom end rot and fruit splitting), and pinch out side shoots on cordon varieties. Towards the end of the month, pinch out the growing tip of each plant to concentrate energy into ripening the existing trusses before the season ends.
- Autumn sowing — Sow spring cabbages, winter salads (rocket, spinach, oriental leaves), land cress and lamb’s lettuce now for autumn and winter harvests. Also sow Japanese onion sets toward the end of the month.
- Strawberries — Cut off the old foliage of strawberry plants that have finished fruiting, leaving the crown and young growth intact. Remove unwanted runners unless you want to propagate new plants.
- Onions & garlic — Onions should now be ripening with foliage beginning to topple. Once the tops have fallen and yellowed naturally, lift them on a dry day and leave to dry thoroughly in the sun or under cover before storing.
- Herbs — Harvest herbs regularly throughout August. Basil can be pinched back to prevent bolting. Preserve excess herbs now by drying, freezing or making herb oils and butters — they will bring the taste of summer into the kitchen all winter long.
- Watering the kitchen garden — In dry August weather, consistent watering is critical to prevent stress, bolting and poor-quality crops. Water deeply at the base of plants in the evening, and mulch bare soil heavily to retain as much moisture as possible.
- Pests to watch for — Vine weevil, red spider mite (in hot dry conditions), cabbage white butterfly caterpillars and late blight on tomatoes and potatoes can all be active in August. Inspect plants regularly and act promptly at the first sign of problems.
🪴 Pots, Containers & Hanging Baskets
- Watering — In August heat, containers and hanging baskets may need watering once or even twice daily. If you are going on holiday, arrange for a neighbour to water or invest in a simple drip irrigation system — even one week without water in hot weather can be fatal to container plants.
- Liquid feeding — Feed all containers and baskets with a high-potash liquid fertiliser every 7–10 days throughout August to sustain the display.
- Deadheading and tidying — Remove spent flowers, any yellowing leaves, and straggly growth to keep container displays looking their very best for the remainder of summer.
🦋 Wildlife, Ponds & Water Features
- Top up ponds — Pond water levels can drop significantly in August heat through evaporation. Top up regularly using rainwater from a water butt where possible. Oxygenate the water by running a hose or fountain briefly during very hot spells.
- Pollinators — Bees, hoverflies and butterflies are still busy this month. Plants such as sedum, agapanthus, echinacea, rudbeckia, verbena bonariensis and lavender are invaluable late-summer nectar sources.
- Bird baths — Refresh bird bath water daily in hot weather — birds rely on garden water sources when natural pools dry up in summer droughts.
- Hedgehogs — Leave a shallow dish of water out at night for hedgehogs and other wildlife. Avoid pesticide use where possible to protect these garden allies.
🌿 August & the Mediterranean Garden — Bring the Sunshine Home
If ever there is a month when a Mediterranean garden comes into its own in the UK, it is August. The warmth, the long evenings and the abundance of sunshine create the perfect conditions for those sun-loving plants that conjure the spirit of a Tuscan terrace or a Provençal courtyard. At Heritage Gardens, we have a wonderful selection of Mediterranean plants including olive trees & a wide variety of Citrus trees.
