Check with your local nursery for specifics in your area. We typically plant, water, and enjoy and then prune back near ground in the fall. I have heard of people pruning in early summer to limit growth and enhance blooms.
What zone are you in? What type of soil?
They are rather tough so I just dig a hole, put a little potting soil in, then drop in the mums. Then water and feed.
This is Linda. Most people plant mums in the fall because that's their blooming time, but some areas have them available in the spring. This article has some tips for planting mums. I hope it gives you the information you need. If not, we can find information for your specific area if you give us that information. :) Wishing you the best.
I’ve tried repeatedly for several years and can’t grow mums, or any plants really except Hosta in my front yard. When we bought our home about 13-14 years ago there were azalea bushes and I had my husband yank them all out. I STILL hear about that!