Do you have to be so tidy? Hoar frosts and the low winter sun will bring drama and a stark beauty to your garden if you leave seed heads, bleached grasses, dried flowers and teasels in place, as Christopher Lloyd reveals
Whether you prefer to see masses of bare soil in the winter garden or to leave the remains till spring of many perennials and some annuals that have a good structure is largely a question of what sort of person you are.
In my garden, spring bedding apart, we leave the main overhaul of our mixed borders till March. Till then, there are many plants whose old remains look picturesque. Furthermore, when we do get down to the main business of replanting where necessary, manuring at the same time, the presence of those remains will remind us usefully of where everything is, what it is and of how tall it grows. Another point: the soil beneath old remains always stays workable. As soon as bared to the sky, it tends to become slimy and like a pudding. I speak of clay soils, of which ours is an example.
Teasels look really imposing in winter and their seeds provide food for goldfinches. The tall and stately cardoons, first cousins to globe artichokes, have enormous thistle heads and this, on a small scale, is the shape of carlinas - Carlina acaulis and the biennial C. vulgaris. These depend on dry weather to open them out wide and look their best.
That also goes for a little autumn-flowering, purple knapweed, Serratula seoanei. In winter, its flower heads become pale brown but are so beautifully shaped as to seem to be in flower again. That only happens when brisk winds from the northeast have quite dried them out, so late winter is often their best moment.
“When do you dead-head your hydrangeas?”, I am often asked in spring, with the implication that I should have done them already. The answer is that I combine their pruning with the removal of spent flower heads. That will be in March but preferably before growth has become so forward that the pruner is apt to knock off prominent shoot buds. One of the best for its large, parchment brown bun-heads is the ultra-hardy Hydrangea arborescens ‘Annabelle’. In summer, this starts pale green, then becomes pure white, like a cauliflower.
All the sedums have slightly domed but basically flat flower heads and, being of strong, stiff structure, they make ideal winter skeletons. The most imposing is Sedum ‘Herbstfreude' (Autumn Joy) (0.5m). It is one of those plants that looks especially striking, even a touch comical, when heaped over with snow. The achilleas have similar corymbs, as these flat heads are known. One of the most grown and most steadfast through winter is Achillea filipendulina ‘Coronation Gold’ (1m) as also the taller Achillea filipendulina ‘Gold Plate’ (1.5m).
At Dixter we have double hedges, linking the ‘peacock’ units in a yew topiary garden, of a michaelmas daisy, Aster lateriflorus ‘Horizontalis’ (1m). It has a stiff, bushy habit and one of its advantages is that it continues to look presentable and well furnished throughout the winter, being especially attractive when sparkling with hoar frost. Aster sedifolius (1m), with dense heads of mauve flowers in August, can also look good in winter, when it is flecked with white seed pappus.
The bolt-upright stems of border phloxes, Phlox paniculata cultivars, are of no great beauty in winter but I leave them till the new year, by which time they are entirely sere and light as feathers. With a low, sideways tap. they can then be knocked over and will break off lower than they could ever be cut. As many of mine are interplanted with snowdrops and tulips, these are then freed of interference as they start growing.
One of the great virtues of many (not all) ornamental grasses is their dominant appearance in winter. The best, in my garden, is Calamagrostis acutiflora 'Carl Foerster' (2m). All fluffy and yielding when it flowers at the end of June, its stems then straighten and stiffen and bleach to pale fawn, appearing like stair rods right through winter till cut back late March.
The oat-headed Stipa gigantea looks good until battered and bared by stormy weather. Indeed, the appearance of many grasses over a long period depends to a large extent on their exposure to weather. Another that is outstandingly persistent is Stipa calamagrostis (1m), its bleached flower heads retaining their elegant, elliptical shape.
All in all, we are missing out on many winter pleasures by being excessively tidy.