The real task in August is keeping the garden going when so many plants are dying back. As there is less to do, each time I’m in the garden I snip away at spent flower-heads to eek out more colour from bedding and herbaceous borders.
If your containers and pots are looking a bit sad, see if you can still find pelargoniums (Geraniums). Mix them up with a planting of maroon, pink and white with gaura lindheimeri, helichrysum and perhaps some of the ornamental grasses (Stipa tenuiissima) or trailing miniature ivy.
Established trees and shrubs can look after themselves but herbaceous plants will simply die back, and lawns will go brown so don’t waste the water, they will soon green up again with autumn rains. Fruit trees and bushes will benefit from extra watering as the fruit develops; otherwise just accept smaller, but richer, harvests. Try to pick up the rotten apples that fall on the lawn to discourage a feast for the wasps.
Slugs abound in my garden and I have found a way of distracting them into one place! Placing half grapefruit skins cut-side down on the lawn seems to provide them with food and shelter and tempt them away from those prize hostas!
Plants in their prime in August and for an Indian Summer:
Trees: Sophora japonica, Eucryphia, Koelreuteria paniculata
Shrubs: Abelia chinensis, Buddleja davidii Nanho Purple , Ceanothus “Autumnal Blue’, Ceratostigma wilmottianum, Clematis ‘Polish Spirit’, Colutea arborescens, Hebe, Hibiscus syriacus, Hydrangea paniculata, Indigofera heterantha, Leycesteria Formosa, Phormium tenax ‘Variegatum’, Potentilla ‘Gibson’s Scarlet’, Sambucus nigra f.porphyrophylla ‘Eve’, Spiraea x japonica ‘Anthony Waterer’
Evergreens: Ceanothus “Autumnal Blue’, Eucryphia x nymansensis “Nymansay’, Gaultheria procumbens, Genista aetnensis, Hypericum x hidcoteense “Hidcote’, Magnolia grandiflora. Myrtus communis, Spartium junceum, Tamarix pentandra, Teucrium fruticans, Vinca minor Ralph Shugert
Climbers: Actinidia deliciosa (Kiwi), Clematis, Eccremocarpus scaber, Fallopia baldschuanuca, Fremontodendron californicum, Lonicera x brownii, Lonicera periclymenum ‘Serotina’, Solanum crispum ‘Glasnevin’, Trachelospermum asiaticum
Anemanthele lessoniana (Grass)
Anemone hupehensis Praecox
Aster x frikartii ‘Monch’
Geranium ‘Azure Rush’
Geum Mrs Bradshaw
Helenium ‘Sahin’s Early Flowerer’
Lobelia x speciosa ‘Dark Crusader’ and L. x speciosa ‘Hadspen Purple’
Nepeta x faassenii ‘Blue Wonder’
Penstemon ‘Andenken an Friedrich Hahn
Phlox paniculata ‘David’
Rudbeckia fulgida var.deamii
Salvia guaranitica, S.nemorosa, S.uliginosa, S.microphylla
Sanguisorbia Canadensis and S.”Raspberry Coulis’ ( from Avondale Nursery)
Stokesia laevis ‘Purple Parasols’
Verbena bonariensis ‘Lollipop’ and V.rigida
Veronica spicata subsp. Incana
Bulbs: Begonia, Canna, Cardiocrinum, Eucomis, Galtonia candicans, Lilium regale
Mow lightly and frequently so that short grass clippings can remain on the lawn to act as a moisture-retentive mulch. If you have a mulching mower then switch it across to the mulch setting; the clippings are returned almost invisibly back into the lawn.
Dig over any areas due to be grassed over later in the year. Leave them for a few weeks to allow weeds to re-emerge, and then spray with a weedkiller to ensure thorough weed clearance before seeding or laying turf in the autumn.
Avoid using fertilizer now otherwise you will encourage lush grass that will be easily damaged in the Autumn and if you feed the brown areas ,they will get worse!
Recut edges and maybe consider digging in a metal edger like Everedge (www.everedge.co.uk/shop/view//1-Classic)
Pruning and renovation
Cut back the foliage and stems of herbaceous plants that have already died back
Cut back your herbs – they should give you another meal or 3 before the frosts get at them
Don’t neglect your hanging baskets and planters – deadheading, watering and feeding with Tomorite or seaweed fortnightly will help them last through until autumn.
Deadhead roses, Dahlia, Cosmos, Penstemon to encourage more buds to open and prolong the display well into early autumn.
Leave the flower-heads of ornamental grasses. These will provide a bit of winter interest.
Cut hardy geraniums back a little to encourage a new flush of growth.
Prune climbing and rambling roses except the varieties that repeat flower
- Prune Wisteria and shrubs such as Pyracantha and Hebe after flowering. With the Wisteria, cut off all the whippy side-shoots from the main branch framework to about five leaves from the main stem.
The hardy lavenders (varieties of L. angustifolia) should be pruned every year to keep them compact. Once established plants have finished flowering remove flower stalks and about 1in (2.5cm) of the current year’s growth, making sure that some green growth remains. After frosts in Spring, this growth can be trimmed to stimulate the plant.
Give hedges a final trim over now. They will only grow a little before cold weather stops growth.
Continue to apply a glyphosate weedkiller to perennial weeds.
Pull rather than cut, faded Alstroemeria, this will encourage a final flush of flowers right through Autumn.
Stake Aster, Rudbeckia and Echinacea to stop them flopping and trailing on the lawn.
Asian hornet alert! – They can kill up to 50 honeybees a day feeding victims to their lavae. Crossing the Channel on vehicles. Report sightings to firstname.lastname@example.org
Things to see:
8th-13th September – RHS Garden Wisley Flower show
members + one guest free
23th August 2-3pm Knebworth House Gardens Late summer colour in your garden. Extending the season. Knebworth , Herts, SG1 2AX