For the last four or five weeks (although at times it felt longer!) we have been busying ourselves with a mammoth hedge trimming effort here in the gardens at Chartwell. Our Yew hedges (Taxus baccata to you and I) have been clipped and snipped into shape and as you can see from the above ‘work in progress’ picture, the before and after appearance is remarkable.
Although we don’t think of ourselves as an overly formal garden, we do like our hedges to to provide a sharp backdrop for all of our informal planting. A well-maintained hedge can also provide a good, smart boundary to a garden, as well as offering privacy and character. They can also screen unsightly views and provide important habitats for wildlife such as nesting birds. But if left unchecked, a hedge can soon lose its shape, look jolly untidy and even end up casting unwanted shade. With a good pruning schedule however, it is possible to keep hedges under control without too much effort.
Yew is widely used in landscaping and ornamental horticulture. Due to its dense, dark green, mature foliage, and its tolerance of even very severe pruning, it is used especially for formal hedges and topiary. Its relatively slow growth rate means that in such situations it often needs to be clipped only once per year, in late summer or early Autumn. Another slight tickle in mid Spring might be necessary to remove the odd wayward growth however.
The aim of pruning formal hedges is to ensure dense growth from the base to the top and to produce it with a neat, often shaped, outline. Formal hedges are sometimes slightly tapered on both sides so that the base is wider than the top and light can reach the bottom of the hedge easily. This is known as cutting the hedge to a batter. The batter permits more even distribution of light from top to bottom thereby reducing foliage loss at the base from ‘shading out’. The top can be straight or occasionally lightly rounded which will actually be less vulnerable to damage by heavy snowfall or strong winds. The snow will fall from the top easier and the high winds will be deflected down the sloping top edges. Here in Churchill’s garden however we opt for the more common rectangular ‘box’ shape for our Yew hedging.
This year we have spent a little longer than usual on our hedge trimming to try and get them looking as good as possible. This is a bit of a luxury but now that we’ve whipped them all into shape, it should make it easier and quicker to maintain this sharp finish in subsequent years. Nobody obviously goes to a garden just to look at the hedges so it is up to each Head Gardener and their team to judge whether the time spent on the process is justified by the finished result. So far all of the comments from our visitors have been very positive indeed!
Under the guidance of newish Formal Garden Supervisor Matthew Law we have been using all sorts of gadgets and gizmos to help us get our lines straight and our tops level. Cutting straight, crisp edges by eye can be difficult. To get our sides dead straight we have been using plum lines and base lines while canes and spirit levels have been employed to make sure you could balance a quail’s egg on the tops without fear of it rolling off!
Small Taxus baccata hedges can be trimmed with hand-held hedging shears. When using shears it is important to always keep the blades parallel to the line of the hedge to ensure that the surfaces of the sides and top, if necessary, are level and flat. More commonly however, formal Yew hedges are maintained with powered hedge trimmers. When using a hedge trimmer the user should always keep the blades parallel to the hedge once again, and use a wide sweeping action, working from the bottom of the hedge upwards, so that the foliage falls away and a smooth cut is achieved. Between Matt, Rhiannon, Ann and myself we have used a combination of petrol driven and battery powered hedge trimmers this year. The battery machines are a tad less powerful but lighter to manipulate and therefore a bit easier on the arms. Either way, as long as the blades are sharp the finish should be fine.
Another very important part of the whole hedge trimming process is the collection of the clippings. In similar pruning situations we would obviously compost the removed material but in the case of Taxus baccata, they are taken away to be used as the raw material for the production of anti-cancer drugs, primarily to treat breast and ovarian cancers. The yew clippings should be one year’s growth from regularly clipped hedges or trees. This is because the required chemical is concentrated in the green, actively-growing parts of the plant. It is also important that the yew clippings are kept fresh – the active ingredient starts to break down as the clippings deteriorate. There are two common chemotherapy drugs developed from Yew trees. One of them, docetaxel (Taxotere), is made from the needles of the European yew. The other, paclitaxel (Taxol) is made from the bark of the Pacific yew. For information on the National Trust’s official standpoint on this process, please click here.
So, job done for another year. Phew! But don’t worry, we’ll be back on our ladders with our ear defenders clamped to the sides of our heads again this time next year when the whole process begins once more. Hopefully we’ll see you all here before then though…