3. Add Cola and Tea to Gardenias
Occasionally watering a gardenia bush with your favourite cola will increase the acidity of the soil, while the sugar will feed microorganisms and help organic matter to break down. And tea? Place tea bags around the base of a gardenia and cover them with mulch. Whenever you water the plant, the ascorbic acid, manganese and potassium present in the tea leaves will trickle down to the shrub’s hungry roots.