Green walls. Or hedges as they are usually called. We were amazed at the tightly clipped, breaking wave hedges at Le Jardin Plume in France, having never seen anything quite like it. They contain the feather garden for which the entire property is named and as such, perform both a practical and aesthetic function. On that practical level, they shelter the very large perennials which could otherwise be beaten down by summer thunderstorms and, presumably, winds sweeping across the flat landscape. And the tight clipping and distinctive form are a complete contrast to the dynamic waves of grasses and tall, slender perennials.
In the same garden the green walls in le jardin d’ été (the summer garden) are less unusual but still performing the dual function of both restraining and protecting extravagantly loose plantings while providing a sharp contrast in style. The hedges are the structure and form within the garden.
We visited another heavily hedged garden in this northern summer just passed. Veddw is in the Welsh borderlands and the owners have used hedging throughout to create the form and structure they were after. In one of the hedged enclosures, they have done a gentler take on rounded shapes, evocative of their wider landscape of rolling hills. It is a sculptural approach where the interest lies in the shapes and reflections in the black pool, not in the plants themselves.
Most of these northern hedges are buxus, yew or beech. In New Zealand, we are generally less favourable towards beech because it is deciduous. Yew is deadly poisonous to stock and also does far better in drier climate than our high rainfall and humidity of Taranaki which tends to kill it off with root disease. Which leaves buxus, now much afflicted by the dreaded blight in many gardens.
Our personal preference is for flowering hedges. Indeed, we pulled out a well-established and perfectly healthy buxus hedge to replace it with Camellia transnokoensis. It is all to do with winter blooming – the single camellia flowers provide pollen and nectar at a time when there are few other sources of this food. Our favourite camellia for clipped hedging is ‘Fairy Blush’, partly because it is our cultivar and the first camellia Mark ever named. It is also scented with the longest flowering time of any camellia we grow, coming out with the sasanquas in autumn and flowering right through to spring.
The aforementioned C. transnokoensis has a shorter flowering season but attractive dark foliage and small, pure white blooms. The third camellia we have made extensive use of for hedging is C. microphylla, even though it flowers earlier in autumn – pure white flowers again and small leaves that clip well. Both these two species set seed. If you can find them growing, you may well find seedlings germinated around their base. Or check for seed in autumn if you are a patient gardener who is willing to put a bit of effort into a free hedge.
All our hedges are flat topped affairs, lacking the panache of both Le Jardin Plume and Veddw but I am eyeing up a somewhat redundant length of buxus hedging and wondering about reshaping it to an undulating caterpillar.
I have been told that New Zealand features more hedges per average garden than most other countries. This may be to do with our being a windy country. Equally, it may be that plants are relatively cheap here and require less capital outlay than building a wall in more permanent materials. However, what may have started from pragmatic origins is a far more environmentally friendly option these days. My advice is to pick a hedging option that will only require clipping once or twice a year and if you are going to be adventurous with the plant selection, do some research first. Hedges need to be from plants that will grow back from bare wood and some less common selections like miro (instead of yew) and Magnolia laevifolia (formerly Michelia yunnanensis) can take a fair number of years before they achieve the dense appearance of a hedge.
We are pretty proud of our remaining length of totara hedge, planted around the turn of last century by Mark’s grandfather or great grandfather and kept clipped for nigh on 120 years.
First published in the September issue of NZ Gardener – my penultimate or maybe final column for this magazine.