Ed is a horticultural therapist, professional gardener and writer. Ed has a BSc in Occupational Therapy from Coventry University and a Diploma in Social and Therapeutic Horticulture (DipSTH) via Thive, the RHS and Pershore College. Ed runs a community kitchen garden in West Sussex, where he leads horticultural therapy sessions.
Reviewed By DAN ORI
Dan has over 27 years’ under his belt caring for plants and gardens. Working as a Horticultural Instructor and Consultant, he draws on a diverse range of experience that includes working as a Head Gardener, Tree Surgeon, Garden Centre Trouble Shooter, and writer of academic papers. Dan has a Level 3 Diploma in Horticulture and is currently a candidate for the RHS’s most prestigious award – The Master of Horticulture.
Damsons are the purple gems of top fruit, not dissimilar to plums, but with smaller and more oval-shaped fruits.
The damson trees upon which the fruit is grown produce a wonderful blossom in the spring, with the fruits being ready to harvest late summer to early autumn.
Damson trees take a long time to mature and produce a harvest, but when they do it is so worth it.
Overview
| Botanical Name | Prunus insititia |
| Common Name(s) | Damson |
| Plant Type | Fruit Tree |
| Native Area | Origins Unknown |
| Hardiness Rating | H5/H6 |
| Foliage | Deciduous |
| Flowers | White spring blossoms |
| When To Plant | January, February, March, November, December |
| Flowering Months | April |
| Harvesting Months | August, September, October |
| When To Prune | June, July |
Sunlight
Preferred
Full Sun
Exposure
Exposed or Sheltered
Size
Height
2.5 – 4.5M
Spread
2.5 – 4M
Bloom Time
April – May
Soil
Preferred
Most Fertile Soils
Moisture
Moist but well-drained or well-drained
pH
Any
Damsons, or Prunus insititia, are small, purple-coloured stony fruits grown here in the United Kingdom for their culinary uses and spring blossom.
They are often, rather sadly overlooked by the common plum and are grown on small trees and crop only once a year in late summer to early autumn.
Commonly grown varieties include Farleigh Damson AGM, Shropshire Damson and ‘Merryweather’ (pictured above).
How To Grow Damsons
Damsons are produced on trees and ready to harvest from August to October in the UK.
They will come true from a saved stone, but you could be waiting many years for the tree to mature and bear fruit.
Most damsons are self-fertile and do not require another nearby.
Damson trees are readily available from online fruit tree suppliers and most often purchased as a bare root tree, grafted onto a specific rootstock to control its growth.
Bare root simply means that it comes with no soil around its roots and is thus easier and cheaper to transport.
Potted trees can be available but at an added cost.
The fruit tree planting season here in the UK is between November and March, when the trees are dormant.
Where To Grow
Damson trees are most commonly planted directly in the ground.
However, they can be available grown on a dwarf ‘pixie’ rootstock that can be grown successfully in a large pot or container.
Tree shapes can include, standard, half-standard and dwarf – some specialist fruit growers even offer damsons as columns, step overs or even fan trained ready to be grown against a wall.
The rootstock they are grown on decides their mature height and spread so it is wise to check this before purchasing, as there is nothing more frustrating than the fruit being out of reach.
Damson trees are happiest in full sun and a relatively sheltered position; south or west-facing is ideal.
Planting
Planting a bare root tree is no more difficult than planting a root-balled tree.
Ideally, a bare root tree should be planted swiftly on arrival to avoid it drying out.
However, this may not be possible due to the ground being frozen or covered in snow; if this is the case store the tree with the polythene around its roots in a cool place like a garage or shed.
The main thing is not to let the root system dry out and so avoid putting it anywhere near a heat source.
To plant:
- Dig a hole at least as deep as the roots and up to twice as wide. If the soil is hard break up the base and sides of the hole with a garden fork.
- Drive in the tree stake close to where the main stem will be.
- Add some fertiliser and lower the tree into the hole, gently spread out the roots and make sure that it is planted at the same depth as it was previously.
- Backfill around the roots so the soil is level with the surrounding soil, gently press the soil down to eliminate any air gaps around the roots.
- Water well and top up the soil if it subsides.
If planting against a wall, it is good to be aware that the adjacent area is often very dry, so it is recommended to plant the tree approximately 30-40cm away from the wall.
Damson Tree Care
Watering
Newly planted trees need watering for the first 2 years, especially during the spring and summer.
Water to the base of the tree, slowly so it can be absorbed.
Unless you are in an urban area place a tree guard around the stem to protect the tree from rabbits and deer as they love to eat the bark.
Tie in the tree to the stake with a suitable rubber tree tie to help protect it and keep it vertical in strong winds.
The stake and tie can be removed once established, usually after 2 years.
Pruning
Damsons are classed in RHS pruning group 1 and require annual pruning in the spring or early summer.1Shrubs and trees: light pruning. (n.d.). Royal Horticultural Society. Retrieved March 14, 2023, from https://www.rhs.org.uk/plants/types/trees/trees-shrubs-light-pruning
It is important not to prune a damson during the winter as this can make them susceptible to silver leaf disease.
Pruning methods usually depend on their form and habit.
Harvesting
Damson blossom signals that spring has arrived – their blossom is a wonderful sight with single, small white flowers.
Damsons are reliable croppers producing a bountiful harvest for years to come, unless a late frost damages the blossom.
If using the fruits for cooking or making jam it is best to wait until the fruits are soft to the touch and a deep purple, usually from August onwards.
If you plan to make gin with them, then the fruits can be picked slightly earlier when slightly firm.
Common Problems
Aphids
The two most common types of aphids that are attracted to damson trees are leaf-curing and mealy plum aphids.
The leaf-curling aphid affects the foliage during spring leading to leaf distortion and the mealy plum aphid which although does not distort the foliage, leaves a sticky honey dew allowing sooty mould to grow.
Check the trees regularly from spring onwards as once any leaves have been distorted by the leaf-curling aphid there is little that can be done.
Non-pesticidal control can include encouraging predators such as ladybirds, hoverflies and parasitoid wasps, as well as squishing by hand.
Pesticidal controls can include using a plant oil wash in winter, fatty acid and oil sprays and insecticides if infestations are severe.
Brown Scale
Brown scale are insects that are found on the woody parts of damson trees.
Small infestations can be tolerated with minimal consequences, but if large infestations occur, they can lead to decreased vigour and growth.
Controls for brown scale are the same as for aphids as above.
Plum Moth
The plum moth can affect damson trees and can lead to caterpillars eating the damson fruit.
The caterpillars are pale pink in colour and are small, only 1cm long.
Usually only the first fruits are affected and ideally should be tolerated as only a small proportion of the crop are afflicted.
Non-pesticidal approaches could include encouraging natural predators.
Pheromone traps that entice the males can be hung in the tree in May, these do not control the numbers but can give a good indication if further action is needed.2Pheromone trapping. (2022, February 14). Forest Research. Retrieved March 14, 2023, from https://www.forestresearch.gov.uk/tools-and-resources/fthr/pest-and-disease-resources/oak-processionary-moth-thaumetopoea-processionea/opm-manual-9-pheromone-trapping/
Organic insecticides with natural pyrethrin as the main ingredient can give effective, but short-lived control.
For more persistent infections an insecticide such as deltamethrin or cypermethrin may be applied.
It is important to note that trees should not be sprayed whilst in flower to avoid any danger to pollinators.
“One good organic control for many damson pests and diseases is to collect affected fruits and leaves as soon as you notice them,” adds Dan Ori, a Master Horticulturist.
“If you don’t want to have a fire to burn these leaves, I suggest adding them to your household waste or taking them to your local council waste recycling centre and disposing of them in the green waste.
“It is important not to try and compost it at home as you will be unlikely to build up the temperatures to kill the pest and diseases that council composting will.”
