Whitebeam (Sorbus aria) is a member of the rose family and is related to the rowan tree (Sorbus aucuparia). Its common name ‘whitebeam’ means ‘white tree’ and refers to the conspicuously pale felted undersides of the leaves. Swedish whitebeam (Sorbus intermedia) is another closely related species. Unlike common whitebeam, it’s not native to Britain, but has been widely planted and now self-seeds in some areas of the UK.
Found growing naturally on woodland edges and in scrub in southern England, common whitebeam grows best in well-drained calcareous soils over chalk and limestone. Common whitebeam trees are often planted in parks and gardens, and used as a street tree, but rarely seen in the wild. There are other related whitebeam species in the UK that are exceedingly rare, such as the Arran whitebeam and Wilmott’s whitebeam. These trees generally exist in very localised populations with only several hundred, or even fewer, individuals remaining.
Sorbus aria is considered a useful species for planting on reclaimed landfill sites. Its timber is hard and white, with a fine grain. It’s traditionally been used for cogs and wheels in machinery, and for joinery and cutlery handles. Whitebeam berries are edible to humans after bletting but it’s worth noting that, like apples, whitebeam berry seeds contain small amounts of cyanoglycosides, so should be avoided. The berries are not reported to be toxic to dogs.
Identifying whitebeam trees
The leaves of the whitebeam are oval and toothed, with white hairs on the underside. They turn gold and red in autumn. Clusters of white flowers appear in May and June, and develop into bright red fruits by early autumn. Whitebeam bark is smooth and grey when trees are young, becoming darker and grooved as it matures.
Common whitebeam can be distinguished from Swedish whitebeam by the shape of the leaves. Unlike the oval leaves of Sorbus aria, Swedish whitebeam has lobed leaves. They are pale green underneath, rather than white like common whitebeam, and they have clusters of slightly larger white flowers.
Size: height and spread
Sorbus aria can reach heights of 15m and a spread of around 8m, depending on growing conditions. Whitebeam grows relatively slowly and starts fruiting after 10-20 years. Trees can live for around 100-200 years in their natural habitat.
Value to wildlife
Whitebeam trees are good for wildlife. Spring blossom provides nectar for pollinators and the leaves are eaten by a range of insects, including moth caterpillars, leafhoppers and beetles. The red berries may attract blackbirds, wood pigeons and mistle thrushes to the garden.
How to grow a whitebeam tree
You can grow whitebeam in moist, but well-drained soil, including chalk, in partial shade or full sun. This relatively large tree is best suited to large gardens, parks and areas of woodland.
Where to plant a whitebeam tree
Plant whitebeam trees in large gardens where there’s room for them to mature and spread. Woodland areas are also ideal locations for whitebeam.
How to plant whitebeam
Plant bare-root trees between November and March, and pot-grown trees at any time of year unless the soil is waterlogged or frozen.
- Dig a square hole and remove weed roots.
- Fork the soil to make it pliable.
- Place the tree in the planting hole and check its depth – ensure it sits at the same level it was in the ground or in its pot.
- For bare-root plants look for the ‘soil tide mark’ towards the base of the stem.
- Once you’re satisfied with the depth, fill around the roots with soil until the hole is filled and firm gently.
- Water well.
- Add a tree stake to prevent root rock. This will need to be in place for around two years.
How to care for a whitebeam tree
During the first full growing season, keep the tree watered during dry spells. Keep the ground around the base clear of grass and weeds for at least a one-metre circle to avoid competition for water and nutrients.
Once whitebeam trees are established, they’re drought-tolerant, wind-resistant and require little care.
How to prune whitebeam
Whitebeam don’t require regular pruning. They can develop an irregular shape in exposed situations, but pruning won’t help correct this. Cut back any deadwood in summer.
Pests and diseases of whitebeam trees
Whitebeam can host a range of insects including aphids, scale insects and sawfly larvae. These form part of healthy garden ecosystems and provide food sources for predatory insects and birds. Light infestations shouldn’t cause lasting damage. Encouraging predators like ladybirds into the garden can help, but avoid the use of pesticides, as these will kill natural enemies and worsen the problem in the long term. Whitebeam can be susceptible to fungal diseases such as fireblight, silver leaf and honey fungus.
Advice on buying whitebeam
- Specialist tree nurseries offer a range of varieties to buy online
- Always check plants for signs of pests and disease before planting
Where to buy whitebeam trees online
Types of whitebeam tree
Sorbus aria ‘Lutescens’ – this compact variety has silver-white leaves in spring, maturing to grey-green, and orange-red berries in the autumn. A resilient tree which thrives in lime-rich soils, but will tolerate acid soils too. Copes well with pollution and windy sites, but suffers in waterlogged soils. Height x Spread: 10m x 5m
Sorbus aria ‘Magnifica’ – upright as a young tree, then developing a more rounded head. Retains its leaves later into the autumn than ‘Lutescens’. H x S: 12m x 8m
Sorbus aria ‘Majestica’ – also known as Sorbus aria ‘Decaisneana’. Another upright variety similar to ‘Magnifica’, with large leaves and fruits. Larger and faster growing than whitebeam ‘Lutescens’. H x S: 15m x 8m
from BBC Gardeners World Magazine https://ift.tt/3rWh6s7
