Hi Tui, why are my lemons rotting on the tree? The little branches are dying off and the tree has yellow leaves. I have given it Epsom Salt and fertiliser, but they did not make any difference.
The rotten fruit is Brown rot, which is a fungal disease. It can be controlled in winter with regular applications of copper based sprays. Spray again after flowering has finished. A few things can be done to help prevent brown rot - collect up fallen leaves and fruit and dispose of in the rubbish rather than place in the compost, this will help prevent the spread of the disease. Wet weather during flowering is when the disease is prevalent. Thin out the foliage of the tree to improve the air circulation throughout the tree, this will reduce the incidence of the disease finding ideal conditions to multiply and infect your fruit. Pick off the infected fruit as leaving them there will only help spread the disease, dispose of in the rubbish, not the compost.
Leave the tree for now, do not feed until spring. If it is in a pot, make sure it has good drainage holes and still gets watered over winter. If you want to, apply Tui Organic Seaweed Plant Tonic every 7-10 days at 70ml per 9L watering can. This is a pick me up tonic and not a fertiliser, it will help strengthen the plants resistance to disease and stimulate root growth.
Thanks, Tui Team.