I've successfully established from cuttings hearths and flowers (aptenia cordifolia) groundcover on our hillside in Waikoloa. It has just about covered the whole hillside. Took over 6 months to get to that stage. But lately patches of it have developed a white cruddy stuff at the roots and then the plant starts to die off. What is this white stuff (fungus?) and how eo I get rid of it? I have the sprinklers set to go off at 7:00 am, so it's not wet overnight, which I'm told sometimes causes problems. Any idea what's ailing it?