Winter Pruning of Limes, Hazels & Dogwoods

Posted on January 14, 2023 by johnshortlandwriter

Hard pruning takes courage and gardeners are often reluctant to carry it out for fear of harming or, even worse, killing the plant. Once it is understood that more trees and shrubs are lost through neglect than by pruning the task becomes somewhat easier. In far too many gardens woody plants are grubbed out because they have outgrown their allotted space when judicious pruning at an earlier stage of their life would have allowed them to thrive and give pleasure for many more years.

*Outgrown its space? Don’t remove it, prune it!*

January and February are the perfect months for carrying out coppicing and pollarding and some shrubs like willow and dogwoods, grown for the winter colour of their bark, are actually improved by the process. Coppicing and pollarding are traditional techniques that have been carried out for centuries in woods and forests to provide a plentiful supply of fuel and fencing materials. As with all procedures, jargon evolves and coppicing and pollarding are just words that describe the removal of branches back to the tree trunk (coppicing) or, in the case of pollarding, the removal of stems to ground level. Somehow, if you just say to yourself, “cut off every branch” the mystery of the process disappears and becomes less intimidating.

*Willows – some newly pollarded line a riverbank*

Limes (Tilia) are very beautiful when grown as full-sized trees but become far too large for most gardens. They are better planted as parkland trees in a field, if you are lucky enough to own one, where there stature and grace can be appreciated from a distance. Too often they are grown where their branches overhang driveways where they drop their sticky honeydew over vehicles and become a nuisance. Most limes are host to tens of thousands of aphids (greenfly) which feed on its sap and then secrete the unwanted waste. Somehow, the gardener’s jargon word ‘honeydew’ sounds so much nicer than ‘greenfly crap!’ If you are determined to plant a lime tree in a confined space the Caucasian Lime, Tilia x euchlora which doesn’t have this problem is the one to go for. Remember that any tree in a confined space will need its size controlled so read on to find out how to pollard it.

*Limes, when mature, are beautiful but very large trees*

The time to pollard a tree is winter and January, when there isn’t too much to do gardening-wise, is the perfect month. I always aim to complete by the 31st which allows time to continue into February, if need be. By the middle of that month the sap will be starting to rise within the tree so it is sensible to complete the task by then. It is very straightforward to remove the branches for which you will need secateurs for smaller twigs, loppers for larger ones and a sharp pruning saw for anything bigger still. Which tool to use when? That too is easy to know. Secateurs and loppers should cut through the stems easily – if you need to twist the tool or the stem, you should be using the saw.

*By midsummer there is plenty of new growth on this old willow pollard*

Common sense will tell you that if you remove all branches from a tree there will be nothing left to offer any screening. This isn’t always important and coppiced trees send out new growth very rapidly as the weather warms up. However, for privacy or a different ornamental effect more careful pruning is required. All that needs to be done is to cut back any branch or twig that has grown beyond the space you have allocated for it.

*A pollarded lime allee provides drama and a focal point*

*This lime allee has had its side branches retained to give denser summer screening*

Limes are not often grown for the colour of their winter twigs probably as they are up rather high and so less noticeable. Willows (Salix) (when coppiced, for they can also be pollarded) and dogwoods (Cornus) are very different for their bright yellow, orange or scarlet stems are very visible and a mainstay for any winter garden. They are also quite simple to prune as it is all carried out at ground level. When the plants are mature, I prefer to cut them over a three year period as this retains their overall height. Quite simply, it means that only a third of the stems are removed or, if you have plenty of shrubs, completely prune one in every three to their base. The purpose behind this pruning is not so much to control their size but to maintain the strength of colour which is at its best on younger shoots. If left, they gradually become quite dull.

Hazels are treated very much like willows and dogwoods, although the usual purpose is purely to maintain a convenient size or to provide ‘pea sticks’ to be used for supporting summer plants as well as peas and beans. For guidance take a look at my earlier post from 2021 which can be read by clicking on the link here.

*A hazel tunnel is created by partial coppicing to reduce the number of tall stems*

The Chelsea Chop

Posted on May 23, 2021 by johnshortlandwriter

Despite its name, the Chelsea Chop isn’t the latest trend in hair styling although trimming the unruly and the straggly certainly is involved. It is a very simple and straightforward method of cutting back herbaceous* plants which, for some reason, terrifies even the most confident of gardeners.

*Sedums (foreground) growing at Lytes Cary Manor*

The only skills required are courage and the knowledge of exactly when to carry out the chop. The latter is simple to calculate and is hinted at by the title of the deed – the week of the Chelsea Flower Show or thereabouts. This year, there have been two hiccups in using this rule: firstly, the show has been moved to autumn because of Covid restrictions and secondly, because spring has been so slow in coming that plants are behind with their growth. As a general rule of thumb, the time for cutting is around the third week of May.

*The flat flowerheads of sedum are made up of hundreds of tiny star-like florets*

Beloved by bees and butterflies, Sedum – also known as Ice Plants on account of their fleshy, cool-to-the-touch leaves – are the ideal candidate for the chop and one of the most satisfying to do. Inevitably, when left to their own devices, the large, flat flowerheads are too weighty for their stems and they topple over to sprawl across the ground and spoiling an otherwise impressive display.

*Sedum, the Ice Plant, frequently collapses & looks ugly just as it flowers*

To make the chop all that has to be done is to cut through every growing stem, thereby reducing the plant’s overall height by half to one-third. Clear away the prunings (which can be added to the compost heap) so as not to attract slugs. There, I told you it was simple!

*Sedum given the chop. Don’t forget to pick up all the prunings!*

Although the method sounds and looks drastic the plants quickly recover and make new growth. The end result will be a plant that doesn’t collapse and doesn’t require staking. Admittedly, the flowerheads will be smaller than before but they produce so many more than they would have done left unpruned that the effect is in no way diminished.

*Numerous flowerheads appearing on the now tight growth of Sedum two months after the Chelsea Chop*

This simple pruning technique can be used on a number of other plants too in exactly the same way. The taller achillea, phlox, campanula, asters (michaelmas daisies) and rudbeckias are all good candidates. I have heard of its use on echinacea (cone flower), penstemon and helenium but, in my experience, these are trouble-free plants anyway, so why bother? The secret to good, stress-free gardening practice is to find the balance of what suits you and what suits the plant. The Chelsea Chop on sedum in May prevents an awful lot of stress later in the year!

*top left – clockwise: achillea, campanula, aster, rudbeckia. They can all be given the Chelsea Chop*

*herbaceous – a non-woody plant that dies back and becomes dormant in winter to regrow each spring

Coppicing Hazel – the how, the why, the where

Posted on February 18, 2021 by johnshortlandwriter

Lamb’s Tails (as country children call them), the pale-yellow catkins of the hazel, are a familiar sight at this time of year. A traditional component of our hedgerows, they are perhaps seen in more glory when growing unchecked along roadside verges where they can achieve a much greater height. There, up to 15 metres tall in favoured conditions, the soft golden shimmer of hundreds of catkins really is one of the earliest harbingers of spring.

*Lamb’s tails: their pollen is released by the wind*

Catkins begin to form early in the winter, small, stubby and dull in colour where they wait until, quite suddenly, they are as we see them now. The transition always goes unnoticed. Even less noticed are the female flowers – for catkins are male. Whereas the majority of plants are self-fertile, Hazel, Corylus avellana, is one of a number that carry both male and female flowers. Wind-pollinated, the breeze carries the pollen from the male to the female to fertilise. However, the pollen has to reach a different plant for it to be successful. The tiny, female flowers can be discovered by careful searching along the branches a few days after the catkins have fully formed.

*The short, stubby embryo catkins form* in early winter

The minute, female flowers take a bit of finding…

For gardeners, hazel is one of the most traditional and useful of plants and it is worth growing one or two in an odd corner if you have the room. There they will quickly create a multi-stemmed shrub. Visually, as a garden plant, when left to its own devices, it is of limited value (wildlife love it, of course). However, by coppicing the plant there will be a regular supply of poles for runner beans to climb and the twiggy top-growth is the perfect support for garden peas, mange-tout and the headily-scented sweet peas. They are also useful for supporting taller herbaceous plants, saving them from collapse and look so much more attractive than canes and string or wire netting. It’s far quicker to do, too!

So, what is coppicing and how do you do it? Well, for a start, it’s a dead easy and very uncomplicated form of pruning! All that has to be done is to cut with secateurs or garden loppers the stems to a few inches above ground level during the winter. If you do this over three years by removing only a third of the stems each year you will have stems of varying heights and diameters without losing any screening effect. Although coppicing may seem a drastic form of pruning they quickly regrow and it also prolongs the life of the plant considerably.

*Coppiced hazel can make a good summer screen in the garden*

Many years ago, coppicing of hazel (and, sometimes, ash and field maple too) was standard practice in many of our woodlands. These days it is still carried out as a conservation tool to encourage the breeding of our now endangered dormouse and other wildlife. Hazel is the food plant of many moths and the autumn supply of nuts are great favourites with jays, squirrels and wood mice – and, of course, humans. In the photo below of long-neglected woodland, the hazel is naturally regenerating as coppice as the old and heavy branches collapse onto the forest floor.

*Neglected storm-damaged hazel naturally regenerating as coppice*

Hazel can be useful, along with willow, to create living structures such as pergolas, arches, fencing and tunnels. They all involve regular pruning in much the same way as coppicing although in most instances the number of upright growths is reduced to one or two. The prunings make excellent kindling for wood burners and, if you’re feeling really creative, rustic furniture. Why not have a go? From just one native species we can have fun projects that are ideal for people of all ages. It can be used as an educational tool too: nature study and conservation, rural history and artistry make it the perfect resource for lockdown and home learning.

*This living hazel tunnel* *makes a fine garden feature and is also good for wildlife*

*An imaginative and practical way of using* *hazel branche*s

Old Yew, New Yew, Renew Yew

Posted on July 31, 2020 by johnshortlandwriter

Although in the UK the yew tree (Taxus baccata) is often called English Yew it is, in fact, very widespread in its distribution growing throughout Europe as well as parts of Africa, Iran and Asia. It can live to a great age and there are several, mostly growing in churchyards, that are thought to be a thousand or more years old. One such tree grows in the Chiltern village that I lived in before moving to the Cotswolds; it is enormous having a girth of over 5.5 metres. Despite being a British native that has grown naturally in the wild for thousands of years, yew woods are very rare – I can only think of two (although there must be others): one in the Chilterns behind Watlington Hill and the other in Sussex. One of the reasons for this is that yew was the favoured timber for making longbows – by 1294 yew stocks were so depleted that imports were being sourced from mainland Europe.

The yew forest at Kingley Vale, Sussex, England – one of the finest examples of this rare habitat in Europe [photo credit: Ben Shade]

The huge girth of the ancient yew in the churchyard at Ibstone , Chiltern Hills, England

Yew is unusual in that the individual plants can be male, female or a combination of the two. All-male trees release huge clouds of pollen whereas all-female produce none and can be identified by their glowing red berries. It has even been known for individual trees to gradually change sex with all-male specimens becoming all-female and vice versa. Although the pollen clouds can be extremely irritating if caught in one, in the average garden situation where mature trees are less likely to be found the pollen release is much more limited.

Swerford Park - Yew Berries(11) watermark

The glossy red flesh is the only part of yew that is non-poisonous. It’s still not advisable to eat it!

In its natural condition yew is a spreading, evergreen tree, wider than it is tall. However, for many centuries it has been clipped and shaped into hedges and topiary for which its regular, and when treated in this way, tight growth makes it ideal. It responds well to being kept low, say around 45cm, or can be stopped at any height required. Likewise, it can be clipped into neat cubes, intricate spirals as well as the ubiquitous peacock beloved by stately homes.

Yew topiary at Hidcote, Cotswold Hills, England

Intricate yew topiary at Farmleigh Gardens, Dublin, Ireland

One of the characteristics of yew is its ability to send out new growth from old branches and even from its trunk. This can be readily seen when the branches are parted or the main stems are exposed. To maintain a clean trunk these growths should be pruned away before they become established. With hedges and trees it means they can be reduced in size as drastically as you might wish although it is important to bear in mind that a heavily pruned tree may never be restored to a thing of beauty.

Yews ability to regenerate from old wood means that it can be pruned as hard as you dare

If reshaping trees is a skill difficult to master, restoring overgrown or gappy yew hedging only takes courage although for best results it may take a few years to achieve perfection. Begin this process by removing all growth back to the trunk on one side only. The hedge will now look ugly but new growth will soon sprout and the following year or in year three the other side of the hedge can be given the same treatment. Apart from the benefit this staggered pruning has to the health of the yew another advantage is that the screening from the unpruned side means there is no loss of privacy. The height of the hedge can also be reduced at the same time as side two cutting 6-12 inches below its required finished height to allow for regrowth. By year five, if not sooner, the hedge will be a manageable, healthy screen once more and will continue to be so for very many years.

The first stage in regenerating an old yew hedge

As with all plants, especially those that are long-lived, careful planting is essential to give them a good start. Yew copes with most soil types including chalk but hates waterlogged or compacted soils. Whatever the soil, enrich with good quality compost or well-rotted manure; if any parts are excessively damp create a low bank at least six inches high to ensure the roots establish in the marginally better drained soil. Pot-grown yews can be planted at any time of the year providing the ground isn’t frozen; the best time is mid-autumn and spring when the soil is warmer. The optimum size for quick establishment is 2-3 feet and this size also makes planting a hedge quite economic too. With a bigger budget larger plants may be purchased. These in the photo below are over six feet high and create an instant hedge when planted closely together. Because of their size they are usually ‘root-balled’ and only available during the cooler months. The hessian and wire mesh root ball should be left intact as they quickly decay once planted although the wire collar may be released if it fits too snugly against the stem. In windy situations they may require staking; they will certainly need careful watering for the first two years of their life.

Rootballed yew waiting to be planted – they will make a fine, if somewhat costly, instant hedge

However you chose to use your English Yew, whether as hedging or as topiary, there is one common rule to clipping and that is accuracy for nothing looks worse than a formal hedge or piece of topiary that does not have clean, sharp lines. The ideal time for clipping is August although spring is the time for restoration pruning. One word of caution – all parts of yew are highly toxic if ingested. It is essential that clippings are disposed of carefully for it can be fatal if livestock such as horses have access to them. Yew clippings from regularly clipped hedges can be sold for use by pharmaceutical companies to make cancer treatment drugs. In the past, when I was the Head Gardener of a large country estate with extensive yew hedging, we secured a not-inconsiderable amount of money over time which the estate donated to cancer research charities. I believe that, for 2020, collection has been suspended but hopefully it will be resumed in future years.