18th November 2018
Established 1872. Online since 1996.

In the garden

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IT’S been a number of years since we’ve had a storm of such ferocity and duration like the one last weekend – a good learning opportunity for gardeners.

One of our super-cloches, supposed to withstand 100mph winds, was left in a mangled heap, with some of its heavily anchored hoops lifted right out of the ground.

It’s since been repaired and securely netted, and if we’re lucky it might survive the winter. It sits above the nursery, on rising ground, in a spot earmarked for erecting a poly-tunnel next spring. The lesson is never, ever to pick a poly-tunnel location on a calm summer’s day. A cloche cover is easily replaced but that of a tunnel is a different matter.

Several large ceramic containers got blown over. Ironically they, and their inhabitants, stood in some of the garden’s most sheltered places, snug against walls, and surrounded by shrubs and trees. They’d fallen “into the wind”, knocked over by the turbulence bouncing back from a hard surface, such as a wall, behind them. In the past I used to herd them all into a place of total safety for the stormy season, but as my compromised back doesn’t allow for the lifting of heavy objects, from now on I’ll just lay them on their sides whenever the wind starts to get up. Many gardeners, myself among them, had been lulled into a false sense of security by season after season of moderate exposure. Des­pite extensive tree planting over the past two decades, the hurricane made us realise that Lea Gardens still lacks significant shelter from the south-west, but, as our land rises steeply to the north, this, even with the help of recently-introduced, fast-growing species from Alaska, is a tall order (no pun intended). An “extremely sheltered” patch of ground, high above the house, and surrounded by mostly evergreen trees on all sides, was selected to house our precious South American plant collection. It turned out to be no such thing when it came under attack last weekend. Wooden pallets, used to build a temporary animal shelter, were lifted in the air like sheets of cardboard.

That same day I stood in the garden’s eastwards extension, in the lee of a shelterbelt. There it was a mild, dull, almost still, autumn day. It was a strange experience to watch that storm rage, with the sea to the south whipped into brown, broiling waters, and waves crashing over the sea wall on to the road. A hurricane that could be seen and heard, but not felt, as the wind was filtered, tempered and reduced to a mere whisper by a broad, dense band of trees. Proof, if it were needed, that natural shelter can transform the hostility of our climate, at least on land, from a ferociously roaring lion into a purring domestic cat.

My instant, but soon discarded, thought was to relocate “South America” to this balmy location. That would’ve entailed moving “Aus­tra­lasia”, parts of “South Africa”, and a newly planted “Jeckyllian” summer and autumn border; far too much hard work, and totally against some of my most fundamental principles.

While I consider exposing a poly-tunnel to unnecessary risk the height of folly, plants always had, and still have to take their chances. Only by exposing them to some of the worst weather can they prove their worth. Some will struggle, some undoubt­edly will succumb, but that is nature. Apart from a few rare treasures, what good is a plant that only survives in the most favourable of locations? After all, the whole garden is built on risk, and without taking risks (within reason) there can be no progress. As always after a tempest the garden was strewn with plant debris, a lot of twigs and a few smaller branches were severed, one of our older willows lost a limb, and a few of the young larches in the shelterbelt have been blown sideways, a sure sign that their anchorage wasn’t all that firm to begin with.

They’re just under two metres tall, and staking is rarely a satis-factory option, even in the short term. Investigating and, if possible, improving drainage is always a good idea in such cases, as water-logged trees have a tendency to rock loose during high winds. On sloping ground, a small network of quite shallow drainage ditches to lower the water table can make a difference.

Some trees, willows in particular, are notorious for putting on far more seasonal growth than their root systems can support, and coppicing them will usually restore the balance. Reducing a handsome tree to virtu­ally nothing is an operation most gardeners are reluctant to carry out, but it is often the only method that ensures long term health and survival – and not only for the tree. I wouldn’t care much for one of those tall, swaying willows I’ve seen all over Shetland crashing down on me during the next gale.

Coppicing is not an option for larch trees, as few conifers have the ability to re-grow from a stump. There are two prescribed treatments. Crown thinning, involves the re­moval of whole branches. When well done, this can greatly improve the looks of a tree but will render it less effective as a provider of shelter. The other option is a thorough crown reduction or drop-crotching, as it’s known in the trade (what a ghastly term). This consists of reducing the length of all branches. Both, but the latter more so, will render the tree less top-heavy, and improve its chances of standing up to the force of Shetland winds.

By the looks of it, we’re probably in for a few more gales this winter, so carrying out these jobs as soon as possible is a good idea. And don’t worry about cutting those willows back really hard, they’ll make up for their losses in no time next year.

Deciduous trees shut down shop and come to little harm, give or take the odd bit of dieback, while evergreens have to bear the full brunt of our climate. Thank goodness this was a rather soggy gale, with plenty of water to rinse the salt off leaves and needles.

As far as our precious evergreens are concerned, it’s the dry winds that do the real damage, and there’s something you can do to ameliorate that. Provided your evergreens aren’t too large and/or numerous, get out the garden h