Posted: 14/06/2013 at 08:26
you didn't say whether your plant is in a pot. Mine is, and I had a similar problem. Than I looked into the compost - it was full with wine veevil larvae. Either soak the soil with an anti-veevil stuff or take the plant out, clean the roots and plant in fresh compost.(But don't put the old compost in you compost bin)
I haver overwintered mine for several years now wrapped in bubble foil in a sheltered corner. Cut it slightly back in spring and give it a feed with good firtiliser.