Blackthorn Prunus Spinosa
PRUNUS SPINOSA - Blackthorn
Blackthorn is a savage thorny, bushy native shrub which forms a dense thicket by suckering. It blooms abundantly in early spring on leafless branches with small, white flowers in fact it is the earliest flowering hedgerow shrub heralding the onset of spring. Though it often coincides with a late cold spell which is called the ‘Blackthorn Winter’.
It is one of the wild ancestors of the cultivated plum. The fruits called sloes are black with a purple-blue waxy bloom and have a dry sour taste, but that disappears with frost or with a night in the freezer. The fruits are used to make jam and brandy, to flavour gin and to colour port.
Where to grow
It will grow to 6m (20ft) if allowed to develop however it is most common as a constituent of countryside hedges and woodland edges.
Did you know?
Blackthorn is an important food tree for birds and bees. Because it forms dense, impenetrable thickets it makes good nesting sites for many small birds. It is also the host plant for many butterflies, as the Brown Hairstreak. The wood is strong and hard, with a beautiful glow. It is used to make walking sticks and historically the teeth of rakes.
- Mature height
- Small - 5-10 metres
- 0-5 meters
- Shrub Multi-Stem
- Growth rate
- Very Fast
- Soil type
- All soil types
- Sun levels
- Partial shade
- Difficulty/hard to grow
- Season of interest
- Autumn colour
- Flower colour
- Flowering type
- Flowering month
- Native Hedge
- Good for Coastal sites
- Good for Windy sites
- Good at altitude
- Encourages wildlife
- Bird Food
For the continued healthy growth of your trees, shrubs or hedging it is vital that you follow the advice below.
The main reason that plants die within 12 months of having been planted is lack of water. It is essential throughout the spring and summer, to give a heavy enough watering to enable the water to penetrate right down to the deepest root level of the tree. In hot dry spells give the equivalent of 2 bucketfuls every three days.
One of the most common causes of lack of water is competition from grass. When trees are first establishing, the grass roots would be at the same level as the tree roots and are far more efficient at taking up water and thus choke the tree. It is vital for 3 years after planting that your tree or hedge has a circle or strip one metre wide completely free of grass. The way to eliminate grass in order of effectiveness is:
- Spray off the grass with a glyphosate based weed killer such as Roundup. Apply each year for the first 3 years. It is best applied when the tree is dormant as it is absorbed through green leaves and kills the plant off at the roots.
- Firmly fit a mulch mat around the base of the tree by tucking the edges into the soil and put a thick layer of bark mulch on top of this. This can be done after the initial spraying with glyphosate and should avoid the need for further spraying.
Mowing or strimming is NOT an answer to the problem. Each time you mow, the grass will grow back more vigorously and strimming invariably leads to lacerated trunks.
If trees are not correctly secured they will rock in the planting pit. Roots not firmly in contact with the soil are unable to take up moisture and nutrients, resulting in die back or death of the tree. Check, particularly after windy weather, that stakes are still solidly in the ground keeping the base of the trunk firm. The purpose of the stakes is to anchor the roots. Flexing in the wind, higher up the trunk, is not necessarily a problem if the roots are firm.
Bellow is list of the correct system to use to secure your trees.
- 40/60, 60/80, 80/100 whips - Unless rabbit/deer problem no need to stake.
- 100/125, 125/150 1.2m Cane and Easi tie.
- 150/175 1.2m square stake and a buckle tie and spacer.
- 175/250, 6/8, 8/10 15L 1.65 Tree stake and a buckle tie and spacer.
- All larger trees. 2 x 1.65 Tree stake and cross rail with 38mm cushion spacer and 1m of 38mm strapping.
Always use our recommended tree ties or strapping. These are designed and manufactured with the correct amount of give to hold the tree firm without strangling it. They should be checked at the end of each growing season for adjustment as the trunk thickens. Non proprietary materials such as baler twine will cut into the bark and should not be used.
Protection from Animal Damage
Rabbits, deer, sheep, cattle and horses can all potentially damage trees. Ask us for advice on the most appropriate guards for your trees or hedge. Squirrels are also a terrible pest when trees get to about 20ft tall but there is no protection available.