Hi Sydney,

There's no easy answer for your question; it depends what kind of lilac you get. See this:

https://www.provenwinners.com/learn/how-plant/lilacs

When you find a type you like, check the label for directions or look the variety up online for guidance.

The most important thing about planting a lilac is to give it full sun. That's how you get the best flowers. Also, if you ever prune the plant do so immediately after the flowers fade. If you cut it back in spring or fall you'll cut off the flower buds.

Hope this helps!