It is important that plants producing oil of the correct composition are used. Flowering types have been found to be more suitable for oil production in Central Otago, but further work to define superior types has not yet been completed. Most sage oil is found in the leaves. Preliminary trials in Central Otago indicate that the highest yields of sage oil from fresh plant material occur before the plant flowers, but the effect of harvest timing on essential oil quality has not yet been completed. Sage is susceptible to few serious pests and diseases providing that the soil remains well drained.
Sclerotinia can cause die-back of branches and eventual death of whole plants in warm, damp weather.
Complete removal of affected plants, followed by fungicide application, is suggested for control. Powdery mildew may build up to severe levels in some seasons, but generally does not require control measures. Various aphids have also been identified on crops at some sites. High levels of infestation cause marked speckling of leaves and potentially reduce crop productivity. A range of insecticides with short withholding periods would be suitable for control if needed.