Instant garden

We only have a small garden below the terrace and it suffers the ravages of heat and drought in the summer as the sun is reflected off the mountain rocks behind the patio. In the winter the problem is the cold for we are at an altitude of around 650 metres. A few plants survive and lots of weeds. This summer the only chance of colour was to opt for the purchase of an instant garden, having first negotiated a mutual loan and water scheme with a friend when we are away. The yucca, however, is a great survivor for it is more than twelve years old and is moved into a garden room each winter and left to fend for itself. I notice large bits of bark have flaked off this winter so I am not sure it is very happy although the foliage looks reasonably ok. I have no idea how to cheer it up. The snow is melting rapidly off Canigou which is not surprising as it 25 degrees this afternoon which is quite unseasonal even this far south.