When choosing to plant mums, consider these factors:
Location: Choose a spot that gets at least six hours of sun a day. Plants that don’t get enough sunlight to produce fewer, smaller flowers and may not even bloom. If you only plan on using your mum for a burst of color on your front porch, sun exposure doesn’t matter as much so long as they are close to opening. However, if you are going to plant it into the ground, they really like full sun.
Soil preparation: Garden mums thrive in well-drained soil. Heavy clay soil should be amended with a peat moss-based soil. If the soil is too dense, add compost and prepare to a depth of 8-12 inches for best performance. Mums’ roots are shallow, and they don’t like competition. Plant them about 1 inch deeper than they were in the nursery pot, being careful with the roots as you spread them.
Watering: Water new plants thoroughly, and take care not to let them wilt. When bottom leaves look wilted or start to turn brown, water more often. Avoid soaking the foliage, which encourages disease and will cause the flowers to brown. If your mum gets too dry, it can lose its beautiful round shape, so be careful not to underwater.
Fertilizer: Plants you intend to overwinter should get Root Stimulator at planting and one more application 2 weeks later to encourage maximum root growth before winter. You do not need to fertilize them THIS year. If you plan on them coming back next year, fertilize them in the Spring.
Overwintering: Prepare mums for winter after the first hard frost. Mulch up to 4 inches with straw, dry leaves or shredded hardwood. Fill in around the entire plant, spreading well between branches. Pinch off dead blooms to clean up the plant, but leave branches intact. Mums have a better chance of surviving if you wait to prune old stems until spring. As soon as the weather warms, pull away mulch to allow new shoots to pop up.