I am very upset for so long time. Some of my kohlerias die before even had the chance to buildup buds. Very stall in growth. Some doing well, still stalling in growth though. Starts from direct below soil line. Stem shrinks a little, becoming redbrownish. Leaves dropping, drying leaves from below to top, plant dying. Stem then is hard and somewhat dry? Roots dry. Why does this happen? I see it more in younger plants. Does this starts from the roots, so stem cant get enough nutritiens up to the leaves? Once I sliced the stem longwise, it was hollow!fungus?thank you. Any advise appreciated. Happens to my gardenia too. Stiff, harden stem, drying plant.
any advice appreciated.