This gardening challenge may require you to hedge your bets

Would you be kind enough to recommend several very fast-growing hedges that need only half a day of sunlight? I would like them to remain full and close to the ground as they grow. They will be in a row about 55 feet by 5 feet tall. We have poor clay soil. — Gerta McKeehan, West Hills
You have a double challenge with only half-day sun and clay soil. For this reason, I would be cautious about committing to a single plant species for such a long hedge. Plant two or three different species in