By Josh Andrews
Fruit trees are many gardeners’ best friends. We watch them grow from saplings into perfectly trained bearers of sweet plump produce, the reward for our patience and hard work.
They need a lot of investment in time and care but do become part of the family; they create memories for little ones and signify the changing of seasons as they cycle through, covering the lawn with blossom, windfall and leaves.
That’s why it’s frustrating when they suffer from disease. It can send a gardener into a panic as sometimes it seems as though the tree will never survive. Luckily, for almost every fruit tree ailment there is a cure, as long as you know what to look for.
These are three of the most common diseases in spring:
Scab
Generally relegated to apple and pear trees, you’ll recognise scab in an instant. You may even see it on the skin of apples from your local greengrocer because on the fruit, the disease is superficial and doesn’t affect its taste once peeled. Scab on the leaves and bark is another matter altogether. It’s a fungal infection that turns leaves yellow (before it’s time for them to fall) and causes black spots on the foliage of the pear. This year your fruit trees are particularly susceptible as we’ve enjoyed a mild winter, the perfect breeding ground for pests and diseases to grow.
Venturia inaequalis from Commanster, Belgium. © Copyright James Lindsey at Ecology of Commanster. Licensed for reuse under a Creative Commons Licence.
The cure: Ensure fallen leaves are raked away from the base of the tree and burn new shoots to the ground until the disease has passed.
Coral spot
Another fungal infection, coral spot is exactly as its name suggests: orange. It usually appears as spores on dead wood but swiftly moves along to living fruit trees if pruning has been less than gentle. If coral spot isn’t treated early enough it can have disastrous consequences, especially to blackcurrant bushes and figs.
Coral Spot Fungus (Nectria cinnabarina). © Copyright Lairich Rig. Licensed for reuse under a Creative Commons Licence
The cure: Make neater, sharper cuts at the site of infection and treat with disinfectant. Treat any other open wounds in the same way.
Fruit split
Fruit split isn’t an infection; it’s a condition that occurs when the water supply is unpredictable. For instance, when heavy rain follows on from a drought it can lead the fruit to become “greedy”, absorbing too much liquid and literally bursting at the seams.
Tomato split. © Copyright Despi Ross. Licensed for reuse under a Creative Commons Licence
The cure: Ensure fruit trees have an even supply of water.
Silver leaf
Silver leaf infects plants between September and May. It is not limited to a single variety and seems to survive on almost any fruit tree or bush. All it needs is a ragged pruning cut or deep wound. As a fungal disease, it is quite mercenary because it will overtake the living wood and kill the plant from the inside out. Leaves will develop a silver sheen that is synonymous with the name.
Chondrostereum purpureum in a garden, Massy, Île-de-France, France. This fungus causes ‘Silver-leaf’. Author: Strobilomyces. Licensed for reuse under a Creative Commons Licence.
The cure: Spot it early, keep young plants away from deadwood, disinfect wounds and be careful when pruning.
With all diseases, prevention is better than the cure so pay special attention when pruning back in autumn, especially if a mild winter lies ahead.
Josh Andrews currently works for Urban Planters, who design and develop floral displays, and supply plants and plant-related products to workplaces and homes around the UK. Examples of some of their interesting plant work include Secret Garden Cafe and ajw aviation.