Posted: 26/09/2017 at 16:59
you don't say whether you are at seaside level or up in the mountains. I garden in Herault, just north of Beziers and have to contend with long hot summers (very very hot and dry this year) but cold winds in winter. Most gardens here have watering systems to cope with the hot weather, but we have not gone down that route as we don't like to leave the water turned on when we are not here. So what has survived the heatwave? Well the tiny cyclamen are flowering abundantly, and sedums tend to do OK though they are really suffering right now - I'll be giving them some water later on. Passionflower has done well and so has jasmine, and the oleanders and camellia that I grow in large pots have also survived, but mainly due to visitors in summer watering them copiously, and also we move all our pots into the shadiest area when we are not here. Lavender should be reliable but even that is suffering from the heat.
If you use the garden centrres (Jardiland etc) be aware that their plants are grown in free draining compost which is h - opeless for plants in a hot climate - you will need to cultivate your soil and add compost almost certainly, then surround plants with heavy large stones to conseve whatever moisture there is.
If you can give us more information I could perhaps be more helpful.