Question about Medinilla and Thunbergia Mysorensis
I 'had' a Medinilla and a Thunbergia mysorensis. The Medinilla, I had for about five years, a huge and beautiful plant, and the Thunbergia for about two, and growing like gang busters. This past March the Medinilla just started loosing it's leaves, perfectly healthy looking leaves. I checked for bugs under the leaves but found nothing, I checked the soil and again found nothing. I sprayed the plant just to be on tlhe safe side. It started putting out new leaves but before they matured they turned black then the stems turned black. Then my Thunbergia started doing the exact same thing. It just started loosing it's leaves and withering. These two plants were sitting side by side in my greenhouse, but the surrounding plants were not affected. The Rangoon Creeper that was on the other side of the Medinilla is growing just fine, so is the yellow orchid vine.
I want to replace these plants but I need to know what I may be up against. Anyone have any ideas what caused the swift demise of my huge and beautiful plants?