Leave those withered flower stems in place
Don't rush to tidy your flower beds and borders, writes Gerry Daly
The display of flowers that we so happily admire is all aimed at reproduction and survival of the species. Plants have evolved to use scarce resources to make flower stalks so as to be more successful in having pollen delivered either by insects or other carriers, and to assist the scattering of seeds, when ripe.
The time of withered stems may not be as colourful as the summer flowering frenzy but it has great beauty of its own. Many people, even keen gardeners, equate colour, flowers and gardens, but there is a lot more to it than that - shape, texture, size and bulk, the latter being more dense.
Most books, until a few years ago, advised the winter cutback and clear-out of withering plants, often taking away one of the great shows of the yearly cycle of plant life. The plant expends a lot of energy making the stem and seed-head, perhaps as much or even more than goes into the production of seed.
Having achieved pollination, the role of the stem switches to seed distribution. The height of the stems is useful for scattering seeds when the seeds mature a few weeks after flowering.
Different plants have their own methods of distribution of seeds. For instance, some thistle-family plants launch feathery thistledown. Other kinds, such as poppies, have shaker seed-heads that are tossed about by the wind and the seed scattered. Some kinds of impatiens have explosive seed-heads that fling the seeds away to new ground.
When their primary purposes of flowering and seed-casting are at an end, the role of these structures is not completely finished. For instance, withered seed-heads and stems can act as providers of shelter for a plant's over-wintering leaves below, and they can act as supports for the soft new stems of the following year. They also act as overwinter shelter for insects of various kinds.
When they finally collapse and fall over, withered stems form a litter layer on the soil surface. This acts as a mulch to keep down competing weeds, helps retain moisture and slowly releases nutrients as the stems rot. The surface litter layer is an important habitat for a variety of predators, such as beetles and frogs, which help to reduce slug numbers.
An understanding of the functions of flowering stems and seed-heads of perennial flowers helps us to appreciate the beauty of their structures. Because they are seasonal, they mark the season in a clear fashion, part of the winter beauty, especially when rimmed momentarily with frost, or crowned with snow.
There are lots of good winter-stem plants to choose from and they often complement each other. Some of the best are the rounded pepper-pot top of opium poppies; the layered whorls of phlomis, the tall spiky heads of teasel, the candelabra shape of hogweed or fennel.
But there are many others: the clustered upright stems of phlox; the rounded tops of monarda; the red, later brown, stems of lysimachia; the tall spires of acanthus, verbascum and foxglove, the knobby heads of echinacea.
Some kinds are not as tall as those mentioned but produce good seed-heads nonetheless such as agapanthus, sisyrinchium and sedum. There are many ornamental grasses that have great stems in winter, such as miscanthus, calamagrostis, stipa and pennisetum.
Rather than clear away the withered stems and seed-heads from perennial flowers, leave them in place. If they get really messy, do not take them away but simply chop them down with a hedge-clippers into pencil-lengths and let them fall to the surface, or pull them away by hand and place them on the soil surface.
The surface litter layer can look messy but it breaks down over winter, recycling nutrients, and it is an easy way to deal with the stems as they get shabby.
Make your own Christmas floral wreaths, garlands and table centrepieces with experts Brian Berry, Therese Kilcullen and Harumi Langford, November 22 and 28 at 11am in Powerscourt Garden Pavilion; €10 per session. Tickets on powerscourtgardenpavilion.com.
Mini-cyclamen are bedecking every garden centre at the moment in shades of red, pink and white. These are still a relatively new plant offering, a hybrid between the large indoor cyclamen and the hardier outdoor kinds, but quite hardy, ideal for winter containers, though last better with shelter from drying winds.
On November 27, popular garden writer and flower farmer Fionnuala Fallon will give a talk on the Education of a Gardener at Foxrock and District Garden Club, Foxrock Church Pastoral Centre, Dublin 18 at 8pm; admission €7 for non-members. All welcome.