My Thunbergia grandiflora's leaves turn light yellow and then brown and brittle. Why only some leaves do this and others are fine? I fertilize with Miracle Grow and 'iron' fertilizer.
Thunbergia Grandiflora Leaves Turn Light Yellow
Certified GKH Gardening Expert
There could be a few reason for leaves or stems dying off.
Is the plants receiving adequate water or to much water?
Is the plant in need of trimming?
Fertilizer applications should be done in spring and fall, not on a continual basis.
Have you inspected the plant carefully for any signs of insects?
Here is a link with detailed growing and care information.