Common name: Morello
Cherry cultivars have gone into decline over recent years resulting with the morello (sour cherry) being the most common cultivar availabe to the general public, although one can still obtain sweet varieties from specialist growers.
This occurence may be down to the fact that the morello has many features that the general public want that sweeter cultivars do not have e.g.
It flowers later than other cherries, reducing the risk of frost damage.
They tend to be more resistant to pests and disease.
It is self fertile, meaning cross fertilization is not required, subsequently only one tree is required which is a boon where growing space is limited.
They tend to be used more than their sweet counterparts in cooking, however they can be sweetened to taste, and their darker colour makes them look more appetising.
Cherries are related to plums, peaches, apricots, and almonds, and require a warm, sheltered site meaning that they are only suited to certain areas of the UK.
The skin of these small round fruits can vary in colour from pale creamy-yellow to deep red to almost black.
The firm juicy flesh can be either sweet or sour, depending on the variety.
Cherries are one of the first fruit trees to flower, it is essential to avoid planting in a frost pocket or exposed area.
Growing against a south or west facing wall / fence will give added protection to the plants.
If growing in grassed areas ensure the soil is free draining soil with plenty of added organic matter.
Keep an area one metre in diameter around the base of the plant free from weeds and grass.
Using mulch in this area can assist with weed control and moisture retention.
When selecting stock,select a self fertile variety a this should give a reasonable crop when grown on its own.
However the crop can be improved if a suitable pollinator is grown nearby.
If planting in a small garden it is advisable to purchase one that has been grafted to a semi-vigorous rootstock.
If growing against a wall, training in a Fan formation will help to control the plants natural vigour.
Flowering and pollination times can vary across the UK from early to late April depending upon location.
Pollination is often dependant upon temperature, i.e. when the weather is warm enough for pollinators to venture out.
Frost and heavy rain can damage blossom resulting in aborted flower heads which in turn will affect yield.
Depending upon height and location of the plant artificial protection such as agri-fleece can be placed over the plants in the evening and removed the following morning to allow the pollinators access.
Harvest time is generally late June to the end of July depending upon location.
When fruit is maturing it is advisable to protect it from birds by covering the plant with bird netting.
When harvesting take care not to damage dormant fruit buds, and harvest the fruit complete with stalks, this improves the keeping quality.
Week 5: Shorten the leaders of all young trees by half over the next two to three weeks.
Week 12: Trees need nitrogen to promote foliage and vigorous growth, phosphorus for healthy growth and fruit and potassium for good fruit-bud development, fruit colour, and flavour.
How much feeding fruit trees need depends on the soil and can be adjusted depending on growth, cropping and soil analysis.
Apply 100g (4oz) of general-purpose fertilizer, and 20gms (¾ oz) sulphate of potash per sq m and Superphosphate 60-70gms (2-3oz) per sq metre every three years
Give slightly smaller amounts of fertiliser to fan-trained trees, where less growth is required.
Week 14: Protect flower buds from bird attack, particularly sweet cherries.
Where only a few trees are grown, protect them with nets.
Week 21: As the trees mature, pruning of sweet cherries can be less severe and after four years entails only the removal of dead wood and unwanted branches.
Prune sour cherries annually throughout their life.
Prune out any badly placed or damaged branches.
Timing of pruning is important to avoid silver leaf disease.
If silver leaf infected branches are removed, ensure that they are cut back 100-150mm (4”-6”) behind the point where the inner wood is no longer stained.
All wounds are best painted with a wound dressing.
Week 22: Ensure regular water supplies in summer
Cherries produce their flower buds the summer prior to flowering and dry conditions or drought at this time can cause flower abnormalities, resulting in incomplete pollination and subsequent fruit drop.
To deter such problems, apply a mulch of organic matter 50-70mm (2”-3”) deep around the base of plants, and water well during dry periods.
Cold spells in late autumn or early spring can also damage flower buds.
Week 28-30: Harvest if ready, if not ready leave the fruits on the trees until fully ripe.
Acid cherries are best cut off the tree with scissors to prevent diseases entering into torn bark.
Week 44: Plant out fan trained trees when they are four years old.
Plant out bush trees, standards and half-standards when they are two years old.
Sweet cherries require a deep, well-drained, slightly alkaline loam.
Acid cherries grow satisfactorily on most ordinary well drained soils.
If planting new trees on light soils, add plenty of organic matter prior to planting to improve moisture-retention properties.
Once the flowers open cherry ovules are receptive for about 10 days.
Depending on air temperature and the cherry cultivar, a pollen grain typically takes up to a week to send its pollen tube down the style of the flower and fertilise the ovary.
Consequently, partial fertilisation can often occur, leading to fruit drop during development.
Even when fruits have reached a good size, some may fall, often in June.
This is usually the result of a growth check caused by cold, malnutrition, moisture stress or natural competition between fruits.