Perennials - Chrysanthemums (Mums)
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  (April) My "mums" sprouting up now are about the 12th-l5th generation. Three years ago an isolated plant started dying off. However, it grows back every year. Last year all the others did the same thing. Black spots develop on the leaves and the stem dies. Now all are sprouting. I suspect a fungus. Would appreciate your expert advice on what it is and what is the cure.

  Mums benefit from division on an annual basis. I would dig them up now as they are emerging, divide and replant. Replant in several new areas, and compare their growth. Continue to pinch them back until mid July, and then leave them alone. If you see spots forming on any of the leaves, take a sample in immediately to your extension office. Since it is not killing the plants outright, it doesn't sound too serious, but we need to get a handle on it. Maybe renovation will help.

  (May) Last fall I purchased some cushion mums. I know that they will grow taller, but they are budding now and looks like they will bloom soon. I understand that I can cut these plants back, but when do I cut them back? Do I let them bloom and then cut them back or do I cut them back now? Thanks for your assistance and help.

  When our mums begin growing early in the year, they get the shorter days that are needed for flower bud initiation, just like they do in the fall. You can enjoy these early blooms, then prune them back and fertilize. You want bushy plants that are short and compact in mid July to have an outstanding display of flowers in the fall. Some people cut off these early blooms, or flower buds, to get more growing time in, but it is your option. I think that allowing some early blooms often prevents them from growing too tall, too early and can prevent some of the legginess we often see. Pinching back is something that should be done regularly to keep them full, if there are no early blooms. If mums are left unchecked all growing season, we end up with mum plants that are three to five feet in height with no foliage on the bottom of the plants, and they flop over under the weight of the blooms, so do prune and do so regularly.

  (September) I need to relocate numerous mums. Should I wait until after they bloom this fall, then cut off tops and then transplant?

  If you have the option, the best time to dig and divide chrysanthemums is as they emerge in the spring. They typically multiply rapidly, and it is best to divide in the season opposite of bloom. If they have to be moved in the fall due to construction, etc. then do so as soon after bloom as possible.

  (November) When is the best time to cut my mums back?

  If your mums have finished blooming and have started dying back, they can be cut back now. If they are still healthy and green, let them grow until a frost, then cut back and mulch.

  Could you please tell me when to cut back cushion mums? Mine was beautiful this past fall, but some have died. Also, should you mulch them after they bloom?

  Cushion mums should all die back to the ground after a killing frost in the fall. Just because the foliage dies back does not mean the plant is dead. They should be beginning to sprout out now. Most types of garden mums benefit from yearly division in the spring as they emerge. You may opt for every other year. Then begin the pinching back process which will continue through mid July. Mulching of the plants helps keep weeds down and makes the plants look more attractive, and it can add to winter hardiness.

  I have a row of small mums in my garden. When is the best time to cut them back to keep them from growing so tall?

  Chrysanthemums should be pinched every two weeks or so through mid to late July, for height management. This should keep them full and bushy. One consideration you should make prior to pruning, is flower bud development. If your plants start growing early in the season, they often will set flower buds in the spring for summer bloom, then again in the late summer for fall bloom. Chrysanthemums set flower buds in relation to short days and long nights. These conditions occur naturally in the fall and spring. If the plants get a jumpstart on growing–such as we had this year, they can bloom twice. Enjoy the bonus flowers, then pinch back as the blooms fade. Avoid pruning past July or you may interfere with flower production.

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