Fall is welcomed by pumpkins and the vibrant fall blooms of mum plants scientifically called chrysanthemum morifolium. Have you overwintered your mums from last year and noticed they grew into leggy plants instead of growing in a compact rounded shape? The new growth in early spring and early summer must be trained to grow into a bushy mum through pruning. If left unattended, the mums will bloom in the summer leaving you only spent flower blooms in the fall. Mums are easy plants to overwinter and I’ll give you my best tips for how to prune mums to get the most out of each plant.
Why Should you Prune Mums
Pruning or pinching back mums is a necessary task to maintain that rounded bushy shape of the mums you see at garden centers. Each year the hardy mums produce new shoots that are a single stem and not bushy. To create a wider and larger mum you’ll need to prune this new growth. Removing the dead stems will also create more room for new stems and flower buds to form.
When Should you Prune Mums
Mums start putting on new growth in the spring. If left to grow naturally, many mums start blooming and produce long leggy stems instead of a compact shape if they are not pruned. You will also hear pruning mums called pinching mums meaning pinching off any leggy growth. Prune mums anytime from early spring through early July. If you prune later than mid summer, you will risk not having any blooms for fall. A good rule of thumb is to perform the last pinch around July 4th.
If you just picked up a mum at your local nursery in August or September the mum has already been pruned by the grower. You do not need to do any pruning of the mum until next spring. Keep reading for tips on how to overwinter mums to avoid buying more plants next year!
How to Prune Mums
In the early spring, start by pinching stems to create rounded bushy plants in time for fall. When the mum is 6″ in height begin pruning. Pinch the stem approximately 2″ – 3″ above the base of the plant and just above a leaf. Pinch off the stem using your index finger and thumb or a sharp pair of pruners. The pinched area will create lateral branch growth resulting in a fuller plant. A second pruning of the mums should be done when they reach a height of 6″ again. Repeat the same pinching process of removing the stem 2″ – 3″ above the base of the plant and above a leaf.
If it is mid summer and you have not pruned your mums, don’t despair! Cut back 1/2 to 1/3 of the total plant growth. This will allow the mum to recover and flower for fall.
How to Care for Mums
Fall mums will bloom for 30 – 60 days providing an array of color during Halloween into Thanksgiving. During the fall season, remove any spent blooms to keep your plant looking fresh. Always water your mums from the base of the plant and avoid soaking the leaves. If your mum is a potted plant, you may soak the planter in a tub of water to ensure the mums receive enough deep root water. Mums require about 1″ of water each week.
Mums require at least 6 hours of full sun every day. Any less sunlight will result in fewer blooms and leggy growth. Full sun does not mean a lot of heat. If you purchase your mums in late summer, you may need to offer them a little afternoon shade until the cooler temperatures arrive.
When to Transplant Mums
Ideally, mums should be transplanted in the spring when treated as perennials to create a well-established root system. Mums are difficult to find at your local nursery until fall, so transplanting in spring will not be possible unless you’ve overwintered your potted mums from fall. Gardeners can transplant mums purchased in the fall into the ground up until 6 weeks before the first frost. The longer the mum is in the ground, the better chance it will overwinter successfully. Choose a planting location with good drainage and amend the planting hole with quality compost. Many southern gardeners can treat a mum as a perennial plant by overwintering it year after year.
How to Overwinter Mums
After enjoying the fall blooms, the mums will go dormant during the winter. Cut back all of the dead blooms, but leave the branches intact. Mulch the mums with 2-inch layer of pine straw or wood mulch. Northern gardeners may need to use up to 4-inches of mulch to protect the plants during the winter months. In the spring, gently pull back the mulch to expose the mum to the spring sun and warmth. The mums will emerge from dormancy and start putting on new growth. Once the mums start producing new growth, fertilize them once monthly with a balanced water-soluble fertilizer. Fertilize mums once per month until blooms appear.
Following these growing tips and pruning tips for mums will result in a more dense plant with beautiful flowers in the fall!
