1 Check clematis for signs of clematis wilt 2 Care for houseplant while on holiday 3 Water tubs and new plants if dry, but be water-wise 4 Deadhead bedding plants and repeat-flowering perennials, to ensure continuous flowering 5 Pick courgettes before they become marrows 6 Treat apple scab 7 Clear algae, blanket weeds and debris from ponds, and keep them topped up 8 Order catalogues for next year’s spring-flowering bulbs 9 Give the lawn a quick-acting summer feed, especially if not given a spring feed 10 Harvest apricots, peaches and nectarines
Things to do this month in the veg garden 1. Water vegetables regularly during dry weather 2 Check for pests and diseases; try to catch any outbreaks early 3. Support branches of heavily laden fruit trees and thin out the crop if necessary 4. Feed tomatoes, peppers and melons with a high potash plant food 5. Pick courgettes before they become marrows
Trees and shrubs
Pruning and training
Prune June-flowering shrubs such as Philadelphus and Weigela after flowering. Prune deciduous magnolias if necessary. Fast-growing hedges such as Leyland cypress should be clipped as necessary throughout the growing season. Tie-in climbers and ramblers as they grow. Propagation Take semi-ripe cuttings of shrubs such as Choisya, Hydrangea and Philadelphus. Root them in pots of gritty compost in a cold frame or even with a plastic bag tied over them. Clematis can be propagated by taking internodal cuttings (i.e. taking stem sections above and below a leaf, rather than cutting the stem immediately below a leaf joint). Air-layering is another method of propagation that can be used for some climbers, such as Akebia, and some shrubs, such as Magnolia. General maintenance Look out for tall, flowering stalks on established bamboos and remove them promptly. Flowering can weaken the plants, as well as being unsightly. Ensure newly planted trees and shrubs do not dry out. They often need much more water than people imagine Remove rose suckers and tree suckers. Pest and disease watch Brown patches on conifers may indicate an earlier infestation by the cypress aphids. Telltale signs include black sooty mould along the stems and shed skin cases. Spraying earlier in the summer may have helped, but once damage is done, conifers can take a long time to recover. Where hedges are affected prune out brown shoots and tie in neighbouring branches to help fill the gaps. Thickened and curled margins on bay trees (Laurus nobilis) are a sign of damage by the bay sucker. Scale insects can also affect bays at this time of year. Neat circular areas removed from the edges of rose and other leaves are telltale signs of leaf-cutter bees at work. These fascinating creatures are best tolerated since damage is rarely severe. Yellow and distorted leaves on cherry laurel (Prunus laurocerasus) indicate a powdery mildew problem. You may notice damage to leaves of Viburnum by viburnum beetles. The damage is not usually bad enough to warrant treatment. Flowers Sowing and planting Autumn-flowering bulbs, such as autumn crocuses, Colchicum, Sternbergia, Amaryllis and Nerine, can be planted now. Some seeds are best planted just after collection, and others may need specific climatic conditions to break dormancy (e.g. some alpines). If unsure, then sow seeds in ‘batches’, i.e. one immediately after collecting, one in winter, and one in the following spring. Cutting back, pruning and dividing Cutting back plants in baskets followed by feeding can encourage new growth and help revive tired displays. Cut back delphiniums and geraniums after the first flush of flowers to encourage a second flowering period. Feed after cutting them back. Deadhead flower borders regularly to prolong flowering. Disbud and dead-head dahlias if growing for large blooms. Leave roses that produce attractive hips. Divide clumps of bearded iris. Plants with a carpet-like growth habit, e.g. some alpines, can become patchy, with central areas dying off. These patches can be in-filled with gritty compost, to encourage re-growth. Propagation Take cuttings of patio and container plants ready for next year. Repot snowdrops if growing in containers. Pinks and carnations that have become leggy, can be propagated by layering or by cuttings. Propagation can improve the appearance of untidy clumps. General maintenance Prop up tall perennials such as lupins, delphiniums and gladioli if staking was neglected earlier in the season. Liquid feed containerised plants and keep well watered in dry spells. Some late-flowering border perennials may benefit from a quick-acting feed before they come into bloom, especially if the soil is not very fertile. Mulching borders can help retain moisture, and keep down the weeds - this will save a lot of work. A really thick layer of mulch (5-7.5cm/2-3in all over) works best. Most perennial weeds are best dealt with in the summer when the weeds are in active growth. Digging out often works, but applying a weedkiller can be more practical, particularly for large areas. Planning ahead Start collecting seed from plants you want to grow next year, especially annuals such as Calendula, poppy and love-in-a-mist. Pest and disease watch Inspect lilies for the scarlet lily beetle whose larvae can strip plants in days. Vine weevils can also be a problem at this time of year. Small holes and tears in new foliage of ornamentals such as Caryopteris, Fuchsia and Dahlia are most likely caused by capsid bug damage. Watch out for aphids (greeenfly and blackfly) on stems and leaves of young shoots. Sudden collapse of apparently healthy clematis, especially the large-flowered cultivars, could indicate clematis wilt. Check Clematis for slugs including ring damage. In dry weather powdery mildew can play havoc with plants such as clematis, roses and Lonicera. Look out for and treat black spot on roses and scab on Pyracantha.