Olive trees are extremely tough and can withstand high temperatures and temperatures as low as -7°c for short periods. They require a well-drained soil and a sunny position. Pot on into a large pot, preferably terracotta and use a loam-based compost like a John Innes no. 3. Add 20% horticultural grit to improve the drainage. keep the soil moist during the growing season as they are fairly drought tolerant plants. Feed with a balanced liquid fertiliser once a month. In winter reduce watering but don’t allow the compost to dry out completely.