Trees are definitely the stars of the autumn season. The changing leaf colour has put on an amazing show and might tempt you to add another tree to your garden. One to consider is Rowan Sorbus aucuparia, which is also known as Mountain Ash because it grows well at high altitudes and its leaves are similar to those of Ash Fraxinus excelsior, although the two species are not related.
Rowan is an attractive, deciduous tree in the rose family, which is suitable for small to average-sized gardens. It is a native tree, which can grow to 15m, with clusters of white flowers in late spring. After successful pollination by insects, these develop into orange-red berries in autumn alongside colourful foliage.
Rowan is one of the many trees in the UK that is said to have connections with the magical world.
Red was considered to be the best colour for fighting evil and so the Rowan, with its bright red berries, was once widely planted by houses as a protection against enchantment. Crosses made of Rowan wood and tied with a red thread were considered to provide protection from witchcraft. In parts of Scotland there was a strong taboo against cutting down a Rowan tree.
Rowan berries are edible when cooked and can be made into wine, syrup and jellies. In autumn and winter, berries in general are a main food source for birds such as Song and Mistle Thrushes, Blackbirds, Redwings and Fieldfares. Rowan berries have smaller seeds, with more flesh, and are preferred by thrushes and Waxwings. In spring the flowers provide pollen and nectar for bees and other pollinating insects. Rowan is also a foodplant for caterpillars and will support a range of moths including Brimstone Moth, Buff-tip and Welsh Wave.
Buff-tip is widely distributed and quite common throughout the UK, although it occurs more locally in Scotland. The yellow-and-black caterpillars live gregariously and feed on a number of different deciduous trees between mid-July and October. The adults fly in June and July and when at rest look remarkably like a broken twig of Silver Birch.
The yellow Brimstone Moth is a common and widespread species in the UK. The caterpillars will feed, between July and September, on a range of other trees and bushes including Hawthorn Crataegus monogyna and Blackthorn Prunus spinosa. Adults can be expected on the wing at any time from April to October, depending on the locality.
Welsh Wave is resident in the northern part of England and Wales as well as Scotland and Ireland and also occurs in the south-west of England. The caterpillar is yellowish-green with brown blotches. Adult moths, which fly in July and August, can be found resting on tree-trunks during the day.
Although container-grown trees and shrubs can be planted at any time of the year, late autumn is a great time to get deciduous varieties into the ground when the soil is moist and still warm. They will become established more quickly and won’t need to be watered as much. Rowan will grow in just about all soils types but prefers slightly acidic soil that is fertile and well-drained but doesn't dry out in spring and summer. Choose a spot in full sun or lightly dappled shade. Prepare a hole that is larger than the root ball and add a layer of organic matter such as compost. Adjust the depth of the hole so that the tree is planted at the same depth as it was originally growing. Fill in and tread the soil around the tree so it is firm. Stake the tree so that it is supported against wind. Water well and apply a thick mulch. Rowan need little attention once established – just minimal pruning in late autumn or winter to remove any broken or crossing branches.
Enjoy your beautiful wildlife tree through the seasons alongside all the visiting creatures.
The Secret Gardener