August is the month when most hedges are cut. There are several reasons for this.
Perhaps post importantly, by now most birds will have finished nesting and so we can trim hedges with little or no risk of disturbing nesting birds. In my own garden there were at least two broods of blue tits this year. I can tell because the fluffy fledglings are so distinctive and there have been lots on the peanut feeders! But all that should be over now.
The other reason we trim hedges such as beech, hornbeam and conifers now is that they will not make any new growth this year. They will stay neat for the maximum time. If you trim in June or July the hedge will make new shoots and need to be trimmed again, in August or September. So August trimming is very practical.
Always take care when using any power equipment. Never work alone, always use ladders carefully with someone holding the ladder, check cables for damage on electric tools and use a power-breaker. Always wear strong gloves and wear goggles, especially if trimming above head height.
As a general rule, trim the hedge so it is broader at the base than the top. This helps light reach the lower parts and can prevent bare bases. For practical reasons keep the hedge to about 2m high. Be aware of local bylaws – you generally need to keep boundary hedges and fences beside footpaths and roads to 2m. Do not allow your hedges to encroach on public footpaths.
Some hedges, such as shrubby honeysuckle and privet, grow continually in summer and may need to be trimmed more than once a year.
Coniferous hedges (with the exception of yew) must never be cut back into old, brown, areas. They will not sprout new growth from these brown areas. You also need to be careful not to allow other shrubs to shade conifer hedges because they will kill the shaded areas and these will not recover.
You can see in this photo (not my garden) where a hydrangea has shaded the conifer hedge and caused a large dead area that will never recover. In a few months the hydrangea will refill the gap again but the hedge is permanently damaged.
Weekly reminders
Summer prune apples and plums
Plant nerines and other autumn-flowering bulbs
Lightly trim lavender – do not cut into bare stems
Take cuttings of tender plants (more next week)
Lift onions, garlic and shallots