Smoke Tree (Cotinus coggygria)
The Green or Common Wig Bush (Cotinus coggygria) grows in light bushes on rocky and dry slopes. It is widespread in the eastern Mediterranean-area, on the Balkan-peninsula and in Asia. There are also natural occurrences in South Tyrol and Ticino. The wig bush belongs to the sumac family (Anacardiaceae), so it is related to the vinegar tree. Thanks to its filigree growth, it enjoys great popularity among hobby gardeners, especially as a solitary wood.
The Smoke Tree (Cotinus coggygria) is an adaptable, medium-sized shrub with a height of three to five metres. With increasing age, it becomes more expansive and puts down its branches drag-nicely. It can then become as wide as it is high. It grows a little sparse, but upright. The ornamental shrub forms ochre branches and yellowish, marrowy twigs covered with numerous cork warts.
The leaves of the deciduous Smoke Tree (Cotinus coggygria) are alternate and inverted ovoid to elliptic in shape. They are about three to eight centimeters long and very thin. The leaves sprout relatively late, but then show a fresh green. In autumn they turn bright orange to scarlet red.
The individual flowers are only about three millimetres in diameter and are rather inconspicuous, but the large and very filigree yellow-green inflorescences are very conspicuous. They form in June and July and often cover the entire shrub – seen from a distance, it looks like it is peppered with small stems of yellow-green cotton candy. Smoke Tree (Cotinus coggygria) are dioecious, which means that there are male and female plants.
The fruits of the Smoke Tree (Cotinus coggygria) are conspicuous tufts that cover the entire shrub with a wig-like veil of thin threads in late summer – this is where the striking name comes from. The “threads” are the filigree, feather-like hairy stems of the unfertilized flowers.
This plant loves it sunny and warm. Although it also thrives in light semi-shade, it develops to its full splendour only in one location in full sunlight.
The decorative ornamental shrub makes only minor demands on the floor and has proven to be extremely adaptable. Basically, it grows on all cultivated soils. However, it prefers a calcareous, moderately nutritious, dry to fresh and well-drained soil. On heavy, compacted and rather damp soils, it is very susceptible to Verticillium wilt, an incurable fungal disease that is usually fatal to the plant.
Shrubs available on the market are increasingly grown in pots or containers – the Smoke Tree (Cotinus coggygria) is no exception. If the bale is well rooted, you can plant it all year round. Outdoor-grown woody plants with root balls should only be planted outside the growing season. It is important that you choose the location for your wig bush carefully, as it is difficult to transplant shrubs that have grown in once. Generally speaking, spring and, in mild winter regions, autumn are good planting times for the wig bush. Just make sure that the soil is not too wet or too compacted and improve heavy soils accordingly with coarse sand. The planting pit should be excavated at least twice as large as the diameter of the bale. Do not set the root ball too deep.
As an ingrown plant, it is reliably hardy and also extremely resistant to drought and heat. Even in the full midday sun he feels comfortable. In addition, it gets by with few nutrients and therefore does not require regular fertilization. It is also one of the few woody plants that prefer mineral soils – so you should rather avoid composting. In dry weather, you only need to water young plants that have not yet grown in well.
The Smoke Tree (Cotinus coggygria) does not need regular pruning to flower reliably and form a beautiful crown. If it spreads too much, you can remove the rooted shoots lying on the soil directly at the base. If older specimens are cut back strongly, the flower will not bloom next year. Red-leaved varieties such as ‘Royal Purple’ have a particularly beautiful, almost metallic shimmering new shoot. If you don’t care about flowering, you can cut back these varieties for a particularly beautiful leaf decoration in late winter.
Smaller, freshly planted plants should be given winter protection from leaves and fir twigs in autumn in order to survive severe frost well. Smoke Tree (Cotinus coggygria) are hardy up to -20 degrees Celsius, which is rarely surpassed in our latitudes.
This plant is particularly suitable for individual placement on lawns – with its unique fruit stalks and its, depending on the variety, sometimes light green, sometimes deep red leaves and not least the enchanting autumn colouring, it attracts attention in gardens and parks. The ornamental shrub can also be combined well with autumn shrubs, ornamental grasses and other autumn-coloured woody plants. In larger rock gardens, the wig shrub also comes into its own very well and, due to its robust nature and high drought tolerance, can be kept well in large planters on the terrace or roof garden.
Even more popular than the green-leaved wild species is the red smoke tree (Cotinus coggygria ‘Royal Purple’). It gets up to three meters high and wide. Its leaves shine metallic and shine in an intense black red. This is a unique contrast to, for example, green lawns and dark green hedges. In autumn it turns orange to fire red.
The yellow smoke tree (Cotinus coggygria ‘Golden Spirit’) is particularly attractive due to its colouring which differs from that of the species. Its freshly sprouted leaves are golden yellow, later greenish yellow. Its flowers are also greenish yellow, which gives the variety an airy, bright appearance. The Small smoke tree (Cotinus coggygria ‘Young Lady’) is a compact shrub that does not grow taller than 1.5 metres. This makes it particularly suitable for planters. It is deciduous like the species, but is especially appreciated for its particularly rich flowering. Flowering time is from May to June.
It can be propagated by sowing in the spring or immediately after the fruit ripens in the autumn. However, higher chances of success can be achieved with lowerers in spring. Lower a side shoot into the Soil and fix it there. The shoot tip should protrude a good 30 centimeters from the Soil. In autumn, when the sinker has formed roots, you can separate it from the parent plant and move it to another location. The plant itself often even provides for propagation by means of lowering, as the side shoots lying on the Soil take root. You can simply cut them off in spring and replant them elsewhere.
Diseases and pests
As already mentioned above, this ornamental shrub is often attacked by the Verticillium wilt in unfavourable locations. The Smoke Tree (Cotinus coggygria) reacts to the fungal disease with lower growth and withered leaves, as the fungus closes the pathways of the shoots. A radical pruning can help in rare cases, but often the infested plant dies. Occasionally powdery mildew also occurs, but does not cause major damage.