Citrus sinensis Orange is an evergreen tree that can grow up to 30 feet in a warm climate but is also good for growing indoors in a terracotta pot in the UK. Orange trees can be grown outside in the summer and look attractive on a patio. Perfect for a hot conservatory or light room and best grown in very well-drained soil and watered regularly in the growing season allowing them to nearly dry out before giving plenty of water. Do not overpot and a terracotta rather than a plastic pot is best as it allows the roots to 'breath'. Orange trees grow deep green leaves with white scented flowers that eventually becomes the fruit. Regular pruning will keep an orange tree looking an attractive shape aiming to keep the middle open to allow plenty of light through.