Second year Mandevilla flowers?

I used to grow Mandevillas in Australia, but the climate, where I lived, was totally different and it would flower during most of the year. Mandevillas do not like cold weather and quite possibly they became dormant; however, they should be having new shoots by now.

I'd give it a bit longer, with the pot in the hottest possible spot (the ones for sale in the markets are forced in heated greenhouses), new compost and kept moist. I know I can't overwinter mandevillas: but I had a palm like plant that 'died' in 2010, produced one miserable leaf in 2011 (which died) , so when proposing to chuck it out this year I was surprised that the roots and bulb-like bit looked solid and healthy, so I gave it another chance in some fresh compost. It has managed six healthy looking fronds this year - so never say die if the roots look healthy! 

Thanks for the info and you're right about never giving up there's nothing more dead looking than an over-wintered pomegranate but they soon getting with a bit of judicious watering