BlackthornPrunus spinosa

Blackthorn

Blackthorns

1. blackthorn
2. sloe

1. blackthorn
2. sloe

1. Prunus spinosa
2. blackthorn
3. sloe

1. Tracheophytes
2. Angiosperms
3. Eudicots
4. Rosids

Rose family

1. Fruit

The blackthorn (Prunus spinosa) is a native, thorny shrub known for its tart fruits. These are harvested after the first frost and are excellent for making jams, jellies, and liqueurs. Blackthorns are undemanding, robust, and provide habitat for insects and birds. They are well-suited for hedges and as a pioneer plant.

1. TaskPruning

   Label

   Pruning

   Prioritymedium

   Months

   1. 3

   Conditiondormant season

   Estimated effortlow

   Notes

   Shaping and promoting fruit yield.

1. TaskHarvest

   Label

   Harvesting sloes

   Priorityhigh

   Months

   1. 10

   Conditionripe

   Estimated effortmedium

   Notes

   Harvest fruits after the first frost.

2. TaskPruning

   Label

   Pruning

   Prioritymedium

   Months

   1. 10

   Conditiondormant season

   Estimated effortlow

   Notes

   Thinning and removal of dead shoots.

1. TaskHarvest

   Label

   Harvesting sloes

   Priorityhigh

   Months

   1. 11

   Conditionripe

   Estimated effortmedium

   Notes

   Harvest fruits after the first frost.

2. TaskPlanting

   Label

   Planting cuttings or young plants

   Prioritymedium

   Months

   1. 11

   Conditiondormant season

   Estimated effortlow

   Notes

   Suitable for vegetative propagation.

1. TaskHarvest

   Label

   Harvesting sloes

   Priorityhigh

   Months

   1. 12

   Conditionripe

   Estimated effortmedium

   Notes

   Harvest fruits after the first frost.

Sunny to partial shade

Adaptable to various locations, but prefers sunny sites.

1. Loamy

2. Sandy

3. Calcareous

1. Well-draining

2. Humus-rich

Undemanding, but prefers well-draining, slightly calcareous soils.

1. Establishment phase after planting

Undemanding regarding watering, avoid waterlogging.

Requires few nutrients, thrives even on poor soils.

Allow ample space due to dense growth and runners. Well-suited for hedges and as a pioneer plant.

Blackthorns are not typical fruit vegetables and have no strict crop rotation rules. However, they can benefit from other Rosaceae family members (e.g., apples, cherries) if they were not planted immediately before.

Deficiency symptoms are rare in blackthorns as they are undemanding. On very poor soils, there may be a deficiency of nitrogen or trace elements.

1. Nitrogen deficiency
2. Trace element deficiency

Main problems are the thorns, which can make harvesting and care difficult. Heavy infestation with aphids or fungal diseases can reduce yield.

1. Thorns
2. Pest infestation
3. Fungal diseases

1. Aphids
2. Spinnmilben

1. Monilia
2. Echter Mehltau

1. Choose a sunny location with good air circulation.
2. Avoid waterlogging.
3. Remove infested plant parts promptly.
4. Encourage beneficial insects by planting flower strips.
5. Regular pruning to improve ventilation.

Look for yellow leaves, sticky deposits (honeydew) with aphids, or gray coating with mildew. Fruit rot appears as brown, shriveled fruits.

1. Slugmonilia-fructigena

   Severitymedium

   Conditions

   1. High humidity
   2. Wet conditions
   3. Damaged fruits

   Affected parts

   1. Fruits
   2. Twigs

   Prevention

   1. Remove infested fruits and twigs
   2. Good ventilation through pruning
   3. Avoidance of injuries

   Organic control

   1. Copper-based sprays (preventative)
   2. Sulfur-based sprays (upon infestation)
2. Slugpodosphaera-pannosa

   Severitylow

   Conditions

   1. High humidity
   2. Poor ventilation
   3. Young shoots

   Affected parts

   1. Leaves
   2. Young shoots

   Prevention

   1. Good ventilation through pruning
   2. Strengthening the plant through proper fertilization

   Organic control

   1. Plant extracts (e.g., horsetail)
   2. Milk-water mixture

1. Symptom

   Brown, mummified fruits that remain on the branch.

   Possible causes

   1. Monilia fructigena

   First checks

   1. Are the fruits damaged?
   2. Was the weather humid during flowering?
2. Symptom

   White, powdery coating on leaves and young shoots.

   Possible causes

   1. Podosphaera pannosa (Echter Mehltau)

   First checks

   1. Is air circulation within the stand good?
   2. Are the shoots young and actively growing?

Diagnosing problems with blackthorns is primarily based on visual inspection. Pay attention to the described symptoms and their respective causes.

1. Leaf-out: March-April
2. Flowering: April-May
3. Fruit ripening: October-December

Flowering occurs before leaf-out. Fruits ripen late in autumn and can often be harvested into winter.

1. 10
2. 11
3. 12

Harvest fruits after the first frost to improve flavor.

Annually, yields can vary depending on weather and plant age.

1. Dark blue to almost black color of the fruits
2. Slight give when gently pressed
3. Improved, sweeter taste after the first frost

Fruits can be processed directly after harvest or stored in the refrigerator for a few days. Wash thoroughly before processing.

1. 10
2. 11
3. 12
4. 1
5. 2
6. 3
7. 4

Freshly harvested fruits have limited shelf life. Preserved, dried, or frozen, they can be stored longer.

Cool and dry, dark

Fresh: a few days to 1 week. Frozen: up to 1 year. Dried: several months.

1. Jam
2. Jelly
3. Liqueur
4. Juice
5. Drying
6. Freezing

Sloes are hardly palatable raw due to their tart, sour taste. They are excellent for processing into jams, jellies, liqueurs, juices, and teas. The tartness is mellowed by cooking or freezing.

Before processing, wash the fruits and pit them if necessary. Heating or freezing makes them milder and sweeter.

1. Jam and jelly

2. Liqueur (sloe liqueur)

3. Juice and syrup

4. Tea (from dried fruits)

5. Baked goods (as filling or flavoring)

1. Fruit

1. Leaves
2. Seeds (contain small amounts of hydrocyanic acid)

The seeds (kernels) of sloes contain amygdalin, which can be converted to hydrocyanic acid in the body. They should not be consumed. The fruits themselves are safe after processing or frost.

Raw consumption is only recommended in very small quantities or after frost, as the fruits are very tart and astringent. Processed, they are safe.

Propagation is best done by cuttings, root suckers, or layering. Obtaining true-to-type seed is difficult as blackthorns tend to hybridize. Germinated seeds require stratification.

1. Cuttings (hardwood or green cuttings)

2. Root suckers

3. Layering

4. Sowing seeds (after stratification)

Cold stratification for 3-4 months at 1-5°C.

Blackthorns are robust, thorny shrubs well-suited for hedges. They require little care and are undemanding.

Blackthorns are an important food source for insects (nectar, pollen) and birds (fruits). The thorny shrubs offer protection and nesting opportunities.