Lilacs need full sun, so find a spot that receives at least 6 hours of sun each day and has good air circulation. Lilacs grown in damp stagnant air or without enough sunshine are prone to disease. Lilacs also need well-drained soil. If drainage is a problem, create a mound or raised bed for them before planting.[2]
Avoid planting lilacs too close to a wall or tree. The lilacs' roots need room to spread out.[3]