Hi Tui, I have a Garden Belle pear tree in a sunny sheltered spot in my garden. I planted it about 6 years ago. For the first time this year it has produced some pears, but the leaves have black spots on them. I don't know what I should do. Should I spray? If so, what and when? Thanks.
This sounds like black spot, which is a a fungal disease that pears are susceptible too. Controlling the disease is to understand the lifecycle of it. Black spot lands on the leaf of the plant and if conditions are ideal (usually wet weather in spring) it will start multiplying. The leaf then drops on to the soil and the fungus is spread on to the surface of other leaves by rain splash or watering.
Protectant sprays such as a copper based spray and plant spraying oil are effective as clean up sprays through winter and into early spring. Your local garden centre or DIY store will be able to recommend a suitable spray. Also, clearing away infected leaf litter from around the tree and disposing of by burning, throwing in the rubbish and not composting will help prevent spread.
Pick off infected leaves as you see them, this is not always practical but it does help prevent the spread. Mulch around the tree to help conserve soil moisture and keep them actively growing. Apply Tui Organic Seaweed Plant Tonic directly to the soil or as a foliar spray. This strengthens the cell wall of the plant and helps it withstand pest and diseases. Water the tree regularly and feed every 3-4 months with Tui Enrich Fruit, Citrus, Tree & Shrub Controlled Release fertiliser.
Thanks, Tui Team.