Miracle-Gro Azalea, Camellia & Rhododendron Concentrated Liquid Plant Food now has a new formulation which contains Humifirst® – highly rich in organic matter. This liquid plant food is suited to acid loving plants like Camellias, Azaleas and Rhododendrons, in pots, beds or borders, and should be applied every couple of weeks between March and September for optimum results. It is child and pet friendly.