Why are my citrus flowers and fruit dropping? I have been told to feed with Sulphate of Potash for flowering, or is there more I can do to prevent this?

• Citrus trees naturally drop fruit and hold on to what the tree can sustain but will also drop flowers and fruit if the tree is stressed. 
• Citrus trees are biennial bearing which means that they fruit well one season and not the next, this is especially true for mandarins and is just nature taking its course. 
• If your tree is newly planted and not well established yet it is a good idea to remove fruit that sets in the first season so that the tree's roots become well established and can support future fruiting. 
• If your tree is in a pot make sure it is consistently watered in spring and summer, and that it does not dry out, and is planted in a free-draining quality potting mix such as Tui Citrus & Fruit mix in a pot that gives the tree room to grow and has good drainage holes.
• Fertilise citrus in early spring (August, September) with a balanced citrus fertiliser, for garden plants use Tui Citrus Food.
• For citrus in pots and containers use Tui Enrich Fruit, Citrus, Tree & Shrub controlled release fertiliser. Feed your citrus again in late summer, early autumn.
• Both of these fertilisers contain potassium (potash) to promote flowering and fruiting as well as ensure healthy growth. Sulphate of Potash provides potassium to plants.  
• If feeding with a straight fertiliser such as Sulphate of Potash a soil imbalance will be created which then restricts the uptake of nutrients by plants.
• The most common reason for fruit drop is sudden temperature changes, too wet and windy at the time of flowering, so bees don't pollinate the flowers. Make sure your tree is in a sheltered position and not exposed to wind.
• Water the tree consistently throughout the growing season, if it is an established tree in the garden water once a week, 5 litres per watering. For newly planted trees and trees planted in pots and containers, water every 2-3 days, 5 litres per watering.
• Citrus don't grow well in poorly drained soils, ensure the soil is well drained and use a quality free draining potting mix such as Tui Citrus & Fruit Mix  for plants in pots and containers.
• Mulch around the tree in spring and late summer, early autumn. Tui Mulch & Feed keeps weeds down, conserves soil moisture, feeds the soil and the tree as it contains sheep pellets and blood and bone.
• To keep your tree healthy and to stimulate root growth as well as help with flowering and fruiting apply Tui Organic Seaweed Plant Tonic every 2 weeks. Mix 60ml in a 9 litre watering can and apply to the soil around your plant.

Read the Tui Citrus Grow Guide

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