By early autumn many of the flowers of summer are distant memories, while others retain an eye-catching presence in the garden.
Alongside the shining hips of roses and the berries of cotoneaster, pyracantha and viburnum the seed heads of perennials possess a faded beauty; longer lasting than their delicate blooms of days gone by. Tidy gardeners, all too quick to cut back and tidy, will miss this later display. Flower arrangers will find seed heads more attractive than their earlier blooms.
When it comes to lasting beauty the alliums excel, but not all are enduring.Some of the showiest, large flowered alliums such as ‘Globemaster’ and ‘Gladiator’ do not produce seed heads that last well, their flowers also have a tendency to get smaller and fewer in subsequent years. Allium cristophii on the other hand is in it for the long run.The silvery lilac blooms develop into wonderful beaded structures which last even longer than the flower stalks that support them. It is not unusual to find perfect seed heads blowing around in the border the following year. This hardy, reliable allium seeds freely and can arise to make spontaneous un-planned creative planting combinations.
Allium schubertii is even more sculptural in the structure of its flower heads. The tiny blooms are carried at the end of long, fine radiating stalks that explode like a firework at the end of a short, stout stem. The colour is as subtle in flower as the seed head is later in the year. Incredibly long lasting this is a lovely contrast to grasses such as the smoky Stipa tenuissima.
Alliums are best planted as dry bulbs in autumn. Plant to a depth of three times the depth of the bulb and make sure they have good drainage by adding sand or grit to heavy soil.Remember that the foliage fades as the flowers develop, so they are best planted amongst other perennials or low shrubs towards the front of the border.
Honesty, Lunaria annua, is well known for its papery seed heads that are often gathered and used for winter decoration. A biennial it is easily grown from seed and that is how it remains in the garden.In late summer the seed pods are rather unattractive until the outer cases fall away. The perennial honesty, Lunaria rediviva is a more desirable plant which lasts from year to year, but still seeds itself and spreads controllably. The seed pods are more slender and elegant, attractive when green and then parchment later in the year. The pale lilac blooms in late spring are delightful and mix well in the border.
Known as angel’s fishing rods, or wand flower, Dierama pulcherrimum is a grass-like perennial with tall, slender, arching stems carrying pendent silky blooms of pink, cerise or purple. The stems dance in the breeze above other perennials or grasses and it grows well in scree or gravel. Dierama hates winter wet, but does not like to be too dry at the roots, so gravel or grit around the plants really helps.After the flowers the beaded seed heads appear. These can weigh down the stems, but they are certainly worth retaining, both for their beauty and because the seeds should eventually fall to give rise to young plants.This is certainly the best way to establish them in the garden.
Enjoying similar growing conditions, the sea hollies are prized for their steely, thistle-like blooms.Eryngium x zabelii ‘Jos Eiking’ is just one of many, but is an excellent variety for its metallic long-lasting grey-blue flowers in mid-summer. The seed heads retain all of their structure and remain unchanged, apart from their colour. They may lose their brightness but their continuing appeal is undeniable.
Baptisia australis, false indigo is a stately perennial of the pea family.Strong upright stems carry abundant grey-green trifoliate leaves. The deep blue pea flowers of summer develop into slate grey seed pods, striking against the foliage which retains its colour.
The foliage of Iris sibirica usually turns gold before it collapses in readiness for winter. Before that happens the old flower stems and seed pods blacken and take on quite a different character from the delicate butterfly flowers of early summer. Not the most dramatic display, but none the less effective amongst grasses and the more dazzling characters of late summer and autumn.
Some of the verbascums are much bolder. The dense spikes of white flowers of Verbascum chaixii ‘Album’ turn to black-brown and provide valuable vertical interest that can last well into winter. A mullein that is often used in prairie planting schemes, this one thrives on chalk soils and is another good subject for scree or gravel gardens.
Apart from the perennials and the fruits of trees and shrubs one cannot overlook the seed-appeal of some woody plants.Many of the acers display beautiful winged fruits.Some magnolias surprise with their bold bods that split to reveal shining seeds.The Judas tree, Cercis siliquastrum is grown for its purple pea flowers that are carried all along the branches in spring. The flattened pea-pods that follow are prolific and green, colouring red-orange as autumn progresses. They become more noticeable as the sun gets lower and the mellow autumn light transforms the landscape.
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