My Meyer lemon is in a large, deep container on our patio where it receives 6-8 hours of sunlight a day. It has set fruit and is continuing to blossom. My concern is that while the fruit it set during winter indoors, the new lemons are getting to around 1-1.5cm and then turning yellow on their way to turning black. The larger fruits (approx 6+cm) are apparently healthy. What can we do and what could be the cause of these issues?
Meyer Lemon Fruit Diseases
Certified GKH Gardening Expert
It sounds like your fruit may be infected with Alternaria Rot or Black Rot.
Are there any other symptoms that the tree is suffering. Leaf yellowing or leaf drop?
The links below have more information to help you.