Hi there. Can you tell me why my gardenia has yellow leaves?

Hi Wendy, it is quite normal for gardenia to have yellow leaves when the seasons change and even though they are evergreen shrubs, they do drop their leaves. Yellowing can also be a sign of a nutrient deficiency such as magnesium, your plant may need a good feed. Feed gardenia in spring and again in autumn. We suggest using Tui Enrich Rose, Camellia, Azalea, Gardenia controlled release fertiliser or Tui Seaweed & Fish. A good dose of Epsom Salts (Magnesium sulphate) may also be beneficial, it can be applied directly to the soil or mixed in a watering can and applied to the soil around the tree. Check the leaves for insect pests such as scale insect or mealy bug, these are sap sucking insects that cause leaves to yellow. Scale insect look like tiny brown bumps on the stem and leaves, mealy bug looks like white fluffy bits on the stem and leaves. Both are easily controlled using a pyrethrum based spray or a horticulture spraying oil, apply every 7-10 days to break the life cycle. The Tui Team.