Choose a Strong Plant
Choosing the right plant is key to having it thrive. A plant that has repeatedly dried out will be stressed and more likely to die when you get it home. If you buy a mum at a supermarket or big box store, be particularly careful, because they often are underwatered. Ask the store what day they get their new shipments and try to buy a plant on the day they get there before they have had too many chances to be neglected. Look for plants with leaves that are deep green and healthy, not droopy. Find plants that have lots of buds and not too many blooms. While some people try to overwinter their mums, it is difficult to pull off successfully (unless you get a hardy mum). In most cases, it is best to treat it as an annual and pitch the flowers onto the compost pile after they die off with the first frost.
Repot Upon Purchase
The single most important thing you can do to increase the longevity of your mums is to repot the flowers as soon as you get them. Most mums are completely rootbound, meaning the roots have taken up the entire pot, making it hard for the soil to retain water. Preserve your plant by providing it with fresh potting soil and a new container that is a little bigger than the pot your mums came in. To repot the mums:
Give Mums Lots of Sun
Mums are sun-lovers, so make sure your pot gets a minimum of four hours of direct sunlight a day. Fall days are shorter than in the summer and the sun has changed positions, so you may find that the places with the most sun have changed. Where you once had full, unobstructed sun, a tree or building may now be blocking the light. Observe how long the sun is hitting your pot each day—you might be surprised.
Water (But Not Too Much)
Mums do not like soil to get dry. When the leaves are drooping—which can happen incredibly quickly—they need to be watered. Try to water them before they get to that point. If you have not repotted your mum, there are two ways to tell if it is dry: Usually, you water a plant until the water pours out the bottom; however, with a potbound mum, it is possible that the water will go around the roots, down the sides of the pot, and out the bottom without the plant getting much water. When the plant dries out, the soil contracts, and the same thing can happen, leaving spaces along the sides of the pot for water to flow out without touching the soil. Rehydrate the dry soil by placing the mum pot in a bucket containing a few inches of water and leave it to soak for a few hours. However, don’t forget about it, as the plant can drown. You can also fully submerge the pot in a bucket of water to rehydrate the soil. Stick a skewer or a pencil in the soil at the top to make sure the water soaks in.
Deadhead the Mums
Deadheading, or removing dying flowers, is one of those tedious garden chores that needs to be done regularly. However, deadheading mums are worth the trouble. The plants benefit greatly from it and look much better when finished. If you keep up with deadheading, chances are the mums will last longer and may repeat bloom.
