Garden Guru: Out with loppers

Fuchsia can be cut back to ground level. It will romp back better than ever. Photo / Supplied

It's usually at the end of summer that we become aware of unruly haystacks of climbers smothering a fence, or shrubs with middle-aged spread leaning drunkenly over a path.

It's then, after the horse has bolted, that we usually head into the shed looking for a pair of loppers or a chainsaw and merrily cut off all the wood that would have had flowers next year. Late summer is one of the worst times to prune anything and though it may not seem the obvious season to get our the secateurs, early spring is an important month if you don't want a jungle by the end of the year.

If you haven't a clue when it's best to prune a particular climber or shrub, there are two easy principles to follow. First prune anything that flowers before midsummer as soon as the flowers fade so new growth has plenty of time to mature to bear next year's flowers.

In early spring it might be forsythia and philadelphus and by midsummer it could be a trim for lavenders, cistus and hebes.

In contrast, later flowering shrubs and climbers are generally pruned before they flower at the start of their growing season just as buds are swelling and frosts are past. These late flowerers - such as fuchsia and hibiscus - tend to flower on fresh growth so you can cut them back quite hard now and they will thank you with a spectacular show in summer.

The easiest group of late-flowering shrubs and climbers can be cut down to the ground in one fell swoop. If you can see growth buds at the base it's best to cut just above them. But this sort of pruning doesn't need to be an exact science; you could use a machete and get away with it.

Plants which respond well to this sort of treatment include old favourites like fuchsias and buddleja. Late-flowering climbers such as Viticella clematis respond well to this brutal treatment too plus perovskia, or russian sage, a beautiful grey shrub with upright blue flower spikes which are ideal for a drought-tolerant planting.

Some foliage shrubs are cut back (coppiced) hard to encourage even larger leaves. Classics include catalpa and some species of eucalyptus.

A large group of late-flowering shrubs can be cut back drastically to a basic framework of old growth. Look for the scars where you pruned back to last year and prune to just above that.

The long branches of hibiscus, scented queen of the night (Cestrum nocturnum) and luculias can be reduced by a half to two-thirds.

The old flowerheads of hydrangeas can be removed and cut back to a fat growth bud while the later flowering Hydrangea paniculata types with cone-shaped white flowers can be pruned much harder to a basic framework.

The harder you cut the larger the new flowers produced will be. Big isn't always best though, for large flowers can flop if wet weather hits. Remove any crossing branches and use a pruning saw to thin out one or two of the oldest growths on the main framework right down to the ground to encourage replacement growth.

If there are no obvious buds to cut back to, don't worry, just form a balanced shape for your framework. Lagerstroemias, the crepe myrtles, are fantastic large shrubs with plenty going for them - peeling bark, autumn colour and frilly flowers. They look more compact and are less prone to being wind-damaged if pruned regularly to a framework. The same goes for luculias and clerodendrons, which have good foliage and are essential for scent in the late summer garden in mild areas.

The last basic way of spring pruning is the light trim, which is useful for shrubs with too many twiggy stems to bother fussing over with secateurs. Lavenders can be tidied up now, especially if you forgot late last summer and the same goes for hebes. In mild areas pelargoniums, plectranthus and Margeurite daisies will need a basic tidy up to keep them pert and compact.

Tender climbers should be tidied up now with a pair of shears. Be brave and create a nice smooth finish.

Pale blue plumbago should be cut firmly to a wall or archway. Bougainvilleas, orange campsis, passiflora, star jasmine (trachelospermum) and mandevilla can all be tidied up in this way. Honeysuckles will need a firm clip to stop them becoming an unmanageable tangle later in the year.

Could do this week

* Take the deadheads off aloes and tidy up native grasses by gently pulling out their skirts of dead leaves.

* Fertilise the garden, especially greedy feeders like roses, clematis, cannas and dahlias. Organic fertilisers release nutrients slowly and are kinder on the soil, however, artificial sorts such as nitrophoska have more concentrated amounts of nutrients and are less bulky to use.

* In the vege garden prepare the soil for planting by digging in compost or manure and a dressing of lime every few years to maintain soil fertility. Start planting spinach, which prefers to grow during cool weather and not in summer. Plant lettuce, broccoli and silver beet in sheltered places.

* Plenty of hardy annual flowers can be sown into trays on a cool windowsill, including classics like violas, alyssum, aquilegia gypsophila and hollyhock.

* Continue to move trees and shrubs until the end of the month.