“Gardening is an unnatural pursuit. The gardener views nature as an abundantly filled grab bag from which he is free to select a number of items he would like to use in his garden, and then dispose of the rest in the trash. But he’s mistaken: once opened, the grab bag turns out to be Pandora’s box, which constantly releases demons that besiege the gardener and his garden.”
Henk Gerritsen, Essay on Gardening (2008)
Autumn is hedge clipping time for many people. The aim is to time it so the hedge makes a light flush of fresh growth which has time to harden before any frosts arrive. If you are in a colder frost-prone area, do not delay because if the growth is still fresh and tender, it can get burned and look unsightly all winter.
If you want the formality of sharp lines, it pays to use a string line. Over time and repeated clippings, levels and lines can start to wobble and undulate and it can take years to try and get them straight and true again – a decade, in fact, for our elderly totara hedge which had previously developed a fair curve. On low hedges, a measuring stick may suffice.
The aim with established hedges is to keep them at the same height and thickness. Trimming encourages dense, leafy growth which is easier to clip. It is only when a hedge has been allowed to get away to a larger size that it becomes necessary to cut back so hard that you can see bare wood. This is best left until winter, not done in autumn. Before you do it, makes sure that your hedge plants will sprout again from bare wood. Most conifers won’t. Buxus, camellias and totaras will.
If you still have buxus hedges, keeping them on the looser side can help reduce the impact of buxus blight. Repeated clipping can render buxus hedges very dense and solid over time, particularly little B. suffruticosa. Dare I say it, thinning your hedge can help air movement which makes it harder for the fungal spores to take hold. If you have a leaf blower, blasting out the build-up of dead leaves and debris in your buxus will also help.
First published in the Waikato Times and reprinted here with their permission.