How to Avoid the Chopping ‘Block’!

-we ‘de-mystify and de-stress’ the process of cutting down herbaceous plants.

With winter well on its way, it is time to renew the great debate about when you cut down herbaceous plants. As garden consultants and designers we find one of our clients’ chief concerns is what to do when. And a routine topic is ‘When do I cut things back?’

The voguish answer is that you leave the tops on herbaceous plants all winter long to enjoy the spectral beauty of the seed heads, particularly with the frost on them, and also to provide food for the birds. The same material also helps protect the crown of the plant from frost. You should, we are told, cut back in the spring.

Well, of course, one person’s idea of beauty is another person’s idea of a mess! Where we garden, in the ‘Banana Belt’ of the south west, there are very few frosts and plants now get into growth at varying times all winter long. An unpleasant rash of nuisance seedlings in the spring also proves that the birds are less than scrupulous in their harvesting techniques.

The truth is of course that life is rarely clear cut and our take on this hotly contested issue is ‘the half way house’. Employing basic common sense, we cut down on a case by case basis. Does the plant still look neat and interesting? Are most of its leaves still green? Some perennials look good all winter long like our great ground cover favourite Phlomis russelliana.  If it does it has a stay of execution.

Or, does it rather resemble a moulting bird or worse still a decaying corpse? If so, it is cut nearly to the ground. Some plants like Miscanthus have attractive seedheads but a tendency for the leaves to blow away in the early gales of winter. Difficult decision, but when they start to fall apart we chop such plants down to avoid chasing the debris round the garden. Easy maintenance wins the day!

Our one exception to this policy would be plants which are tender. Books and labels in garden centres highlight these very clearly. Even a few stems and leaves left on these treasures can be enough protection them through the winter. Many Salvias and Penstemons, for example, are best left with their tops on until the weather warms in the spring. And even in the south west we never cut Penstemons back until after the drying, cold winds of March. A winter long tangle of lax growth is the small price to be paid for the glorious summer flower which tender perennials offer.

 If you proceed on this basis, only cutting back what is rough and visually offends, gradually, after the luxuriant growth of the summer months and the bronzed disorder of Autumn, order begins to reign. Neat dark soil, or mulch if you are a conscientious gardener, appears in places. But, while there are fewer dishevelled hens, neither is the border a totally bare Siberian waste.

You also don’t loose the last few flowers on say Salvia guaranitica. If you have done your plant selection well there will be a fair few of these late flowerers. So it will not just be the odd plant which decorates your winter borders. From a design perspective you have also usefully started to work out which of your border perennials are the stalwarts and, with most of the winter ahead of you, you have the leisure and time to divide and repeat them to give your border a strong winter presence.

There are further logistical benefits to this approach. Dead, loose debris is removed early and simply before the wind redistributes it. Access to the border is itself easier and you can therefore thoroughly weed. This is important for garden hygiene and tidiness, since weeds, which can be hosts for pests, are now growing all winter long. In one of our clients’ gardens, nasty little Brome Grasses have a tendency to invade clumps of other more ornamental grasses-these can easily be caught early on before they get too deep a hold.

Overall it is also the case that the work can be tackled in bite sized chunks during suitable weather. On sunny autumn and winter afternoons this can be pleasant, gentle exercise. Adopt our approach and you will not get caught out in a busy spring, wading amongst emerging bulbs, with all the cutting down to do, when the growth has already started, which you can then all too easily damage in your chopping down.

Have we convinced you? Gardeners have long known that cutting back after flowering often leads to a second crop of flower. By a further refinement of this, the so called Chelsea Chop which is actually delivered at the time of Chelsea Flower Show, you can delay flowering and limit height. It is this responsiveness to plants and the seasons which is a key part of being a gardener and which we do all have within us. Our ‘half way house’ approach to the great border tidy up simply takes this responsiveness to its logical conclusion. Go to it!

Lesley and Robert

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