One thing that your Rhododendron will need is some shade from the hot sun, Difficult in Malta but not imposible. Then it will need a good bed of humus rich, acid soil. My memory says that Malta is a limestone island so you will need to buy an ericaceous compost for it. Is it a large or a small Rhododendron? If it is a small one then you could grow it in a container but remember that the roots want to spread so it needs to be a wide container. Then, keep it moist and cool.