Although a trace element, iron can be locked up in the soil so roots of azaleas, rhododendrons, camellias and other ericaceous plants cannot absorb any reserves. Raspberries can also show similar signs of deficiency.
Leaves turn pale yellow between the veins.
Treatment and control
General tips: Use a special ericaceous plant food that contains sequestered or chelated iron that is more easily absorbed by plant roots. One application of Murphy Sequestrene Granules will provide all the iron necessary for strong growth. Where plants need supplementary feeding at the same time, apply Miracle-Gro Azalea, Camellia & Rhododendron Soluble Plant Food or Miracle-Gro Azalea, Camellia & Rhododendron Liquid Plant Food through a watering can or sprinkle the granules of Levington Azalea, Camellia & Rhododendron 'Plus' Plant Food around plant roots in spring.