Pruning Hedges

© 2024 CTC Productions Pty Limited. All rights reserved. The material presented on this website, may not be reproduced or distributed, in whole or in part, without the prior written permission of CTC Productions.

If you live on a busy road, it’s a great idea to screen out passers-by and vehicles by planting a hedge. Hedges will also act as windbreaks, although they won’t cut down on street noise.

The row of Leyland cypress shown in our segment was planted as a privacy screen. Don pointed out that left unpruned, these conifers could eventually reach around 30m (100′) tall. The owners of the home would then find they had a disaster on their hands, with the conifers growing up through the liquidambar and their front yard in deep shade. Don felt that there was no alternative but to prune the conifers, even though that meant the owners would have to continue to prune them every year.

Leyland cypress (xCupressocyparis leylandii)

The Leyland cypress is what is known as a bi-generic hybrid, which means it is a cross between 2 different genera. It originated in Wales in 1888 from a chance cross-pollination of Cupressus macrocarpa and Chamaecyparis nootkatensis. Many forms and cultivars have since been developed and planted by the millions worldwide, mainly for screening and hedging. These upright, evergreen trees are very fast growing, and hardy in a wide range of soils and climates.

Pruning the hedge

Hedges are green, living fences and they should conform to the rules of basic fencing. When pruning take a line of sight from some existing geometric feature in the garden, such as a wall or path. There was an existing fence in front of the row of conifers, and although the fence was not horizontal it followed the same slope as the footpath and the road. Therefore Don decided to prune the hedge so that it ran parallel to the top of the fence.
To work out how high the finished hedge should be, Don stood on the footpath and looked across at the windows of the house. The hedge had to be high enough to give the occupants privacy when in their bedroom. Once the right height was determined, a string line was put around the entire hedge at that height. String lines help to keep the pruning straight and level.
Rather than leaning across the hedge while trying to balance on a ladder, Don set up a plank between the rungs of two stepladders. He then pruned the hedge, taking care not to cut the string lines. Secateurs were used to trim wood around 2cm or thicker – hedge trimmers can be used for a light trim and tidy up after the initial pruning is done.

After pruning it is a good idea to apply a mixture of 50% Nitrosol and 50% Seasol using a hose end applicator. This mixture stimulates both leafy growth and root growth. Keep your hedge well watered, especially during dry spells over summer. When the hedge reshoots, trim lightly with shears or a hedge trimmer to encourage further dense new growth.

Further information

Both Nitrosol and Seasol are readily available at hardware stores and nurseries.