Curb your enthusiasm for tidying dead stems
THE first touch of frost brings an abrupt halt to the growth of many perennial flowers and causes their leaves, until now green, to turn brown and quickly wither. Often this is a signal for those with a predisposition for tidying to rush out and whip away all signs of withered foliage.
But in doing so, they are likely to take away one of the great seasonal beauties of the garden -- its sere and shriveled stems. As soon as they dry out, the structure of the stems and seed heads is revealed in its most bare and stripped-down form.
The shape of many stems and seed heads is very distinctive, lending great character to a border. Each kind is different -- for instance, the waving heads of grassy miscanthus, the flat dark brown heads of sedums, the tiered whorls of phlomis, the arching stems of dierama, the rounded shape of poppies and the candelabra shape of fennel.
The palette of colours changes, too. As the green is withered away by frost, the leaves at first appear brown and slowly they bleach out to shades of beige, palest grey and off-white. Against the bleached stems, the seed heads are often darker in colour, such as those of centaurea, rudbeckia and monarda.
It is interesting to note that many of the plants with good stems are prairie plants from various grassland areas of the world. These plants grow in a matrix of competitive grasses and they have to reach higher to show their colourful flowers to pollinating insects. As a result, the seed heads are carried high on the stems.
The dried stems and their seed heads, when tossed about by gales, act as seed-shakers, distributing the seeds over the neighbouring ground. Some of them from the thistle family use the tall stems to launch their thistledown seeds which are carried away on air currents.
Of course, not all plants have decorative stems -- some kinds just collapse with frost, such as hostas and lupins. The lower leaves of many plants wither and slowly disintegrate over a period of months. Plants such as hardy geraniums and alchemilla hold their withered leaves in place to act as ground cover, just as they did when green and living.
Very often the withered leaves remain intact until new leaves are produced in spring and only then does the old foliage rot and is recycled into the soil.
Do not be in a rush to tidy away the withering stems of the season or you will denude the garden of an important part of its winter charm. By all means, take out messy or ugly stems but leave the bulk of them in place. Bejeweled with frost or a dusting of snow, they will be even more delightful.