Lilly Pilly Backyard Bliss drooping in half - Help!
I planted these Lilly Pilly as a privacy hedge. During dry periods, they can drop quite a few leaves but with some extra water and liquid fertiliser, they come back. This season has seen heavy rain (Brisbane) and the trees have drooped over in half. I thought it was the weight of the rain on the leaves, but I was wrong. Can you suggest a solution - Mulch? Sand to break up clay? Fertiliser?
03 December 2021 04:04 PM
As with most plants - including Lilly Pillies, drainage is key for long term plant survival, success and health. We don't recommend planting trees into clay soils.
In an attempt to improve soil drainage, many people dig into clay, thinking that removing the clay will help to remedy this, however, this essentially creates a water-well that just fills with water after prolonged rain. Best thing to do is leave the clay soil as is, and bring in more soil. You can either create very wide and gentle sloping mounds of soil; or, raise the soil level entirely by creating garden beds . For either option, the soil depth needs to be at least 40 cm to create ample drainage and space for roots to grow. As the plants are already in, these are not really an option for you now, but something to consider for future plantings.
Poor drainage, clay soils, and wet conditions can encourage soil borne root diseases such as Phytophthora Root Rot. From the description provided, this is a likely cause of the plants drooping as they have done after wet conditions, and being in a clay-to-clayey-soil. Best thing to do is improve drainage, avoid watering, and apply Yates Anti Rot Phosacid Systemic Fungicide.
Apply compost, and Yates Dynamic Lifter Soil Improver & Plant Fertiliser to help with soil structure and quality. For the time being, avoid the use of mulch to help the soil dry out. When very wet conditions desist, apply mulch up to 8 cm deep, keeping away from the base of the trunk.