I bought an indoor plant which was unidentified and I thought was a Garvinea. As they are meant to be super hardy and developed in Netherlands for outdoors, I planted it straight outside into some peat reduced mixture. Within 4 days all the leaves have fallen off. It's warm here in summer. It doesn't seem to have adapted too well. Could I have bought something else?
It appears that this pot is to large for your plant.
Generally a blooming potted plant is quite happy in it's original pot while it is blooming. After blooming if it appears root bound you could repot but only go up 1 size in pots.
Also watering in pots during the warm summer temperatures is very important. You may need to water twice a day if the temperatures are over 85 degrees.