I would like to plant an evergreen Magnolia Grandiflora in my zone 7/8 Pacific Northwest garden. The space I have in mind is along the fence bordering the neighbour's house (I'd like to screen it). The potential planting spot is in a raised southwest facing sunny bed with good, well-drained soil. My backyard garden near this area has tender exotics- musa basjoo (hardy banana), palms, new zealand flax, etc. I'd like the tree to grow 25-30 feet tall and about 20 feet or so wide to screen the neighbour's house and to complement my "exotics" theme. What particular cultivar should I plant? Does anyone have any other suggestions for exotic evergreen screens? (not bamboo) How cold-hardy are the grandifloras? I lost 2 eucalyptus this winter.