Feeding, pests and common disorders

Top fruit is not a hungry crop. A 5 cm mulch of garden compost each March provides all the nitrogen and trace elements a tree needs. If growth is sluggish — less than 20 cm of new wood per year — scatter 35 grams of sulphate of potash per square metre around the drip line in February. Avoid high-nitrogen fertilisers; they produce soft growth that attracts aphids and reduces fruit quality.

Codling moth is the classic apple pest. The larvae tunnel into developing fruits in June and July, leaving the telltale frass-filled hole at the blossom end. Pheromone traps hung in the canopy in late May catch male moths and reduce the next generation. For serious infestations, spray with Bacillus thuringiensis in early June when the eggs hatch, targeting the blossom end of each fruitlet. Pears suffer less from codling moth but are hit hard by pear midge, which causes fruitlets to blacken and drop in May; there is no organic control, so pick off and destroy affected fruits immediately.

Scab is the fungal disease you will see most often: dark, corky patches on fruit and leaves. It thrives in wet springs and on varieties like Cox and Discovery. Rake up fallen leaves in autumn to break the disease cycle, and choose resistant varieties like Sunset or Scrumptious if scab is endemic in your area. Canker appears as sunken, flaky lesions on branches and is common on badly drained soil; cut out infected wood back to clean tissue and burn it. Pear trees are prone to fireblight, a bacterial disease that makes shoots look scorched; if you see it, report it to the Animal and Plant Health Agency and cut out affected growth 60 cm below the visible damage.

Biennial bearing — heavy crops one year, nothing the next — is caused by letting the tree overcrop. Thin fruitlets in early June to one per cluster, spaced 10–15 cm apart. This sounds brutal but it results in larger, better-flavoured fruit every year instead of a wheelbarrow of marbles every other year.