In summer the tasks that need to be undertaken are based around pruning fruit trees that are prone to suffer from peach leaf curl, a disease that affects plums, cherries and gauges which weakens the tree and reduces fruit production. Pruning in summer is thought to protect the tree from infection as the spores of the fungus pathogen are not active in summer.
Summer is also the time to prune summer fruiting raspberries. If possible feed the raspberry canes every two or three years with manure or compost.
Summer varieties fruit on one year old canes. Therefore cut out any canes which fruited during the summer after they have finished fruiting, and cut out any that are damaged or diseased.
This often happens naturally when a tree had produced a lot of fruit - it will drop a quantity of fruitlets in May or June. If the tree still looks overloaded, thin out the fruit in May or June. This will increase the size and quality of the fruit left on the tree, whilst protecting the tree from broken and ripped branches caused by too heavy a crop when the fruit is fully ripe.