Position
Plant your Morello cherry tree in a sunny spot where it won’t get too much wind. But be aware that these trees like cold winters and cool to moderate summers (not hot). Afternoon shade or netting ensures that the tree is protected from the sun in the afternoon to avoid sunburn.
The best time to plant your tree is in autumn or winter so it can get acclimitized during the colder part of the year.
Size
If left unpruned, your cherry tree will reach a height of about 3.5 metres at maturity (around seven years old). It can be pruned to a height of 2 metres, making it easier to pick the fruit over the years. Give your tree about 5 metres of space.
Soil Type
Cherries thrive in well-draining soil that is fertile and can retain moisture. A pH of 6.5 is ideal, but anything between 5.0 and 8.0 should be fine.
Mulch
Use about 8 cms of organic mulch to help add nutrients to the soil, retain moisture, and keep weeds at bay. Use wood chips, hay, or partially-composted sawdust. Keep the mulch 15 to 20 cms away from the tree trunk to avoid rotting.
Watering
Water the tree well in warm, dry conditions. For the rest of the year, ensure the soil is moist, not wet, flooded, or waterlogged.
Fertilising
Morello cherries need more nitrogen than sweet cherries. Fertilise your tree once a year (in the early part of spring) with a low-nitrogen fertiliser, such as 5-10-10.
Pruning
Pruning is essential to encourage your tree to produce fruit. Lob off any diseased, damaged, or dead branches, but don’t aggressively prune it until it has produced its first crop. The fruit is produced in mature trees on the previous year’s long stems and short branches. Prune each stem from last year to half its length. Remove old wood to allow the tree to focus its resources on the fruitful boughs.
Harvesting
Your sour cherries are ready to enjoy when they come off the stem easily. They don’t ripen once they’re picked, though, so be sure to harvest them when they are ripe.