It depends where you live. If you live in a warm climate (Zone 7 or warmer), a south facing wall may get too hot during the afternoon. If you live in a northern climate (zone 6 or colder), a south facing wall could prolong your growing season as well as protect your plants from late frosts.
Like all vegetables, globe artichokes like rich, well-drained soil. I use lots of compost in my veggie garden. It enriches the soil and improves the texture.