Pruning Mahonia

One of the biggest concerns for many people, even experienced gardeners is how and when to prune.  The quicker growing the plant (Wisteria is a good example), or the more spiny it is, the less likely it is to be given the chop – the first is intimidating by size, the latter by pain.

A close relative of that most vicious of shrubs, the Berberis, is Mahonia and the garden cultivars,  Charity and Winter Sun, brighten up many a dark corner with their spikes of yellow, lily-of-the-valley scented flowers on a cold winter’s day.  There they grow untroubled by pest or disease becoming ever taller, lankier and ending up just plain, downright ugly.  All of this can be prevented by pruning with the additional bonus of having flower spikes at nose height.

The Mahonia in the photo below has not been left to grow tall but been given a regular clipping with shears to form a ball shaped shrub: this often happens to plants that have to be kept under control resulting in a garden full of ‘blobby’ shapes.  For a Mahonia that, by nature, wants to be upright, this is an especially hideous way to end up.  The shrub to the fore is Sarcococca, the Winter Box, also clipped to a ball shape, a style that does suit that particular plant although, in my opinion, it is more attractive when allowed to grow naturally.

By April, the elongated flowerheads (raceme) will have faded to be replaced by bluish berries.  This is the sign that pruning time has arrived.  Mahonias are very tough, coping with temperatures as low as -20 degrees Centigrade and I have pruned them in frosty weather without loss.  It is always best, however, to do any pruning task when the weather is more clement.
The difficulty with seeing inside a shrub that is growing as densely as this particular Mahonia is easily resolved by simply cutting off a few of the top clusters of leaves anywhere.  Once you can see what you are doing life is much more straightforward and those first random pruning cuts can be rectified later.  In the photo below a branch has been revealed to show how the leaves join the main stem.  The newer growth at the top is a much paler green than the darker, older wood but both have leaves growing from it.
The pruning cut can be made anywhere between the leaves – I tend to be quite drastic and only leave one or two leaves in place.  It can be seen that I have cut this stem hard back into the older, darker wood – new growth will shoot from this point giving flowers again by the following winter.
Gradually, the shrub opens up to expose many branches of varying ages.  The older they are the more gnarled and twisted they have become.  Once these are readily visible it is possible to cut some of the oldest growth much harder still: this thins out the plant allowing more light and air to reach its centre.

Although no growth is visible below the cut, dormant buds will break and create new branches.  Again, these will flower the following winter but, of course, at a much lower height than before.
The end result is a shrub that has had much of its centre removed or lowered.  In this particular example, I have left more of the outer growth in place as this gives a more attractive appearance through the summer.  Next Spring this outer growth will be pruned more severely exposing the newer growth inside which can be pruned much more lightly.  By the Spring of 2014 this  mahonia will have been transormed back to its natural shape, a mass of healthy stems, leaves and flowers.

It was only when I returned to the bonfire that I appreciated the beautiful pale jade tones of the underleaf, not normally noticeable.  Another feature of Mahonia is the bright yellow colour of the cut stem – one that it shares with its Berberis cousins and, like them, the root system is also coloured yellow, a useful way of identifying what root system belongs to it when digging in a crowded shrubbery.

 Click on any of the photographs to enlarge them

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Sun, Drought, Frost: at last, Rain…..

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It has been difficult to remember, sometimes, that it is still only spring time. After the unusually early, bitter and snowy winter weather we experienced, 2011 came in cold but dry. It remained so until the end of March when, wham!, summer arrived.
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With temperatures soaring into the mid 80’s, many plants struggled to open their buds (and the ash trees still haven’t done so properly). I had planned to write about this battle but became – as you may well know – rather obsessed with puppies ….
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However, many plants did rather better than normal. Tulips, especially the fragile doubles, were better than ever with no rain to spoil their petals, as have been the paeonies. Perfume has wafted about the garden in the warm evening air – can there be anything more lovely on both eyes and nose than this paeony and wisteria combination?
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The trees, later than has been usual for many years, finally started to come into leaf. Now the countryside is awash with May, cherry and Horse Chestnut blossom. It is all quite stunning. Or was.
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Out of nowhere, on Monday night, we had frost. The first for over five weeks, this was no slight touch of cold but one that turned the secret valley into a white valley of death. Well, I admit, that is rather an exaggeration but, I imagine it is due to the very hot temperatures immediately before, some plants – and especially the trees – have been decimated. One moment their new leaves hurt the eyes with their iradescent green, the next they are brown and shrivelled. Some, depending on how the cold air lay, have come through unscathed whilst their neighbour has been hit badly. Will they recover? I expect so but, possibly, too late to help the insects and birds that rely on the food source at this very moment. Time will tell.
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Just when our feelings were at their most depressed, the weather gave us another surprise. Rain. The first for many weeks, we have been desperate for it. The ground has been cracking, the river getting low, plants wilting and, worst of all, the farm crops not growing. In places, the young corn has started to go yellow. And when we least expected to get any, we awoke to the sound of rain on the windows. Our only neighbour, the farmer whose corn was suffering, and I were standing in the field below our homes, getting soaked and almost hugging each other with joy. It gave me just the slightest awareness of how people in countries that really suffer from prolonged droughts must feel. And it also made me aware of this rather primitive reaction of wanting to literally dance in the rain when it first arrives.
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. The old mortar in the garden is beginning to fill once again!
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The paeonies have been ‘knocked for six’ but, who cares? Apparantly, we have only had 1.5mm of rain during March and April compared with the 40-50mm in an average year. Let it rain for days now to restore the balance. But – as a gardener speaking – please only at night and only fall gently……
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