Tasks in August

Flower garden

Deadhead, water and feed pots and hanging baskets.
To prolong the flowering well into early autumn deadhead bedding plants, Dahlia, rose and Penstemon.
Cut back the foliage and stems of herbaceous plants that have already died back.
Cut back hardy geraniums can be to encourage a new flush of growth.
Prune climbing and rambling roses that do not repeat flower or produce attractive hips, once the flowers have finished.
Propagate pinks and carnations by layering and irises by rhizome dividion.
In duller weather with some rain propagate perennials by dividing once they have finished flowering.
Take cuttings of rock garden plants and tender perennials such as Pelargonium and Osteospermum.
Collect seed of hardy annuals and perennials for sowing later in the autumn.
Buy or order spring-flowering bulbs. Bulbs, such as Colchicum, daffodils and Madonna lilies can be planted now.
Alpines can be tidied up by in-filling the patches with gritty compost.
Treat perennial weeds in active growth with a weedkiller containing glyphosate. Inspect chrysanthemums for the first signs of white rust and take immediate action.
Prevent powdery mildew by treating with an approved chemical at the manufacturer's rates.

Trees and shrubs

Prune Wisteria and shrubs such as Pyracantha after flowering.
Deadhead shrubs, such as roses, to extend flowering into early autumn.
Hebes and lavenders can be given a light prune after flowering.
Rambling roses can be pruned once they have finished flowering.
Give hedges a final trim over now.
Cut back spindly shrubs that have lost leaves to encourage new growth.
Thoroughly soak drought-stressed plants and shrubs, especially newly planted ones.
Keep early-flowering shrubs such as Camellia and Rhododendron well watered to ensure good flower bud initiation.
Remove large shrubs and trees that were casualties of winter waterlogging and summer drought.
Semi-ripe cuttings can still be taken to propagate many common garden shrubs. Rhododendrons, azaleas and Clematis can be propagated by layering.

Lawns

Lawns on thin soils may benefit from a high phosphate feed.
Mow lightly and frequently so that short grass clippings can remain on the lawn during hot summers.
Raise the blades on the mower before cutting fine lawns in order to reduce drought stress.
Avoid using lawn weedkillers in late summer - they will be more effective in the cooler, damper autumn weather.
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 or hoe off.