I love lilacs! I wish I had more space to dedicate to plants that got 5-15 big! I have my massive lilac in the front (she's about 12' tall, about 8' wide and about 20 years old), and a smaller common lilac in the back (only about 6' tall, 10' around.. I trimmed it pretty harshly a few years ago) that are older. I've put in 3 maturish Charles Joly & 1 "teenager" (like 4'square) Mount Baker, but my Primroses, James McFarlanes, Dappled Dawn (shade tolerant), Wedgwood, & Saugeana are all babies (Dappled dawn is like a pre-teen being about 3' tall & about 2' around). They just take forever to grow, but they're so worth it! If you can afford the bigger bushes (10-15gal), I'd recommend buying those. HD usually has them starting now for like $50/ea. But it's instant flowers!