Iron deficiency in plants results in pale yellow leaves, poor growth and flowering, and is the main reason why rhododendrons, heathers, camellias, magnolias and other “lime haters” cannot be grown well on chalky or alkaline soils. Vitax Sequestered Iron Plant Tonic supplies the necessary iron, together with magnesium and manganese, in a form plants can use to correct the deficiency. Vitax Sequestered Iron Plant Tonic should be mixed with water and applied in early Spring using a watering can. One application lasts all season. There are four 20g sachets in each pack.