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 (that is, not hot). Afternoon shade or netting that ensures that the tree will be protected from the sun in the afternoon is advisable to avoid sunburn.
The best time to plant your tree is in autumn or winter so that it can get established 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 7 years old). But, it can be pruned down to a height of 2 metres to make it easier to pick the fruit over the years. Give your tree about 5 metres of space around it.
Soil Type – Cherries thrive in well-draining soil that is fertile and able to retain moisture. A pH of 6.5 is ideal, but anything between 5.0 and 8.0 should be fine.
Mulch – Use about 8 centimetres of organic mulch to help to add nutrients to the soil, retain moisture, and keep weeds at bay. Use wood chips, hay or partially-composted sawdust. Remember to keep the mulch about 15 to 20 centimetres away from the tree trunk to avoid rotting.
Watering – Water the tree well in warm, dry conditions. For the rest of the year, ensure that the soil is moist, but not wet, flooded or waterlogged.
Fertilising – Morello cherries tend to need more nitrogen than sweet cherries. Fertilise your tree once a year (in the early part of spring) with a low-nitrogen fertiliser like 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 prune it back aggressively until it has produced its first big crop. In mature trees, fruit will usually be produced on the previous year’s long stems and short branches. Prune each stem from last year to half its length. Remove old wood too to allow the tree to focus its resources on the productive 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’re ready.