I have a number of mock orange in hedges, some of the plants are not growing and have yellow leaves. Is this lack of water or is a fertilizer needed in this area. Some sections may have soil from different sources, as we have added to garden beds. We have just removed larger aussie southerns and lilly pillys nearby, and hope that it will help the plants that are struggling
17 January 2019 02:33 AM
assuming soil pH is around 6.5, if the yellowing is all over the plants or mainly older leaves then it is nitrogen deficiency - apply Thrive soluble to moist soil every 2 weeks til colour returns. if it is the new growth mainly and the veins in the leaves stay green, then it is iron deficiency - apply iron chelates to the soil once only and colour should improve inside a fortnight with adequate watering - 2 applications at most - if this doenst help then iron isnt the problem. if the soil is very poor then it could even be both. Dynamic Lifter pellets or Yates Acticote can be applied to provide ongoing nutrients.