A hedge against intrusion
How much do we value our privacy from the outside looking in?
For centuries hedges have been used to divide individual properties, to separate field crops and to define the line between public and private land. In more recent years they've been used as a screen or barrier to create privacy from ‘the outside world'.
The desired function should, to some degree, dictate the type of plant used, as should property location. If for privacy, how close is the house/patio to the road or neighbours? Is the property next door a single or two-storey building? Are surrounding properties on the same level, or is there land with higher elevations?
If the property is in a sheltered location, plant selection is greater than in exposed areas where the choice is more limited to hardy material that will withstand the impact of wind and salt spray better than ‘soft' material.
In sheltered locations one has the choice of flowering plants and, if necessary, deciduous material. In exposed locations it is best to use hardy material, with choice based on the required function.
Height of hedge will also, to a degree, dictate selection. To make the obvious statement, ‘plants grow naturally' and continue to grow until action is taken to arrest their growth.
This is by the act of pruning which unfortunately is where most of the problem lies in creating a dense — or, if flowering, a floriferous — nature. As I have said on numerous occasions pruning is a lost art, and the machete is a tool of the Dark Ages. Constant hacking of each side and across the top of the hedge simply produces a collection of branches which have a covering of foliage on the top and sides with little, if any, growth in the centre of the plant.
It is a rule of thumb that new growth is generated 6in to 8in from below a pruning cut; when viewed in profile from one end it looks like a tunnel, with threads filling the area. Constant hacking retards flower production by removing the potential flower bud which is forming in the leaf axil of the branches that have been removed.
Plant type will, to a degree, dictate the trench line. If, for example, you are considering a hibiscus hedge as hibiscus generally grow about 5ft round, to keep the plant in bounds on your property it should be planted on a centre line 4ft in from the boundary.
Pruning should only be undertaken in spring and autumn, and perhaps in August if we have had heavy rains and lush growth. Once growth crosses the boundary it can be pruned by a neighbour or the Department of Parks — if on a public way. As a result, the density of the hedge could be lessened by poor pruning techniques or the ‘weapon' used.
One-gallon or four-gallon plant containers are preferred, with the latter being the best for quick growth (though more expensive). I suggest either a trench or individual holes when planting. The former should be 2ft wide and the same depth, whilst individual holes should be 2ft square and 2ft deep. If soil in area is poor, import a mixed compost to use, which will give quicker growth. Planting distances on centre should be 5ft apart, especially for four-gallon size plants.
Using one-gallon material will take much longer to fill in but is less expensive. If using one-gallon material, still plant at 5ft apart, plants do grow!
Let us examine the types of hedges commonly found in gardens and plants that would be of service in these areas. Plants are either evergreen or deciduous, the former giving the best privacy level and the latter being more decorative.
Hedges mostly used in protected areas include: hibiscus (hibiscus rosa-sinensis); Scotchman's purse (malvaviscus arboreus); Match-Me-If-You-Can (acalypha wilkesiana); cape honeysuckle (tecomaria capensis); oleander (nerium oleander); mock orange (murraya exotica).
Hedge used for more exposed areas include: Japanese pittosporum (pittosporum tobira); spruce (tamarix gallica.); grey buttonwood (conocarpus erectus sericea); sandankwa viburnum (viburnum suspensum); kopsia (ochrosia elliptica).
As the adage goes, measure twice and cut once. Many hedges are installed with plants far too close together which is a waste of money, often requires increased maintenance and can be deleterious to future maturity by overcrowding of growth.
• Malcolm Griffiths is a trained horticulturalist and fellow of the Chartered Institute of Horticulture in the UK. He is also past president of the Bermuda Horticultural Society, Bermuda Orchid Society and the Bermuda Botanical Society