Chrysanthemums or ‘Mums’ are a stalwart of the autumn garden. A lot of gardeners wait until the end of the season, to purchase mum plants that are already in bloom They are beautiful, but chances are good they won't over-winter and be perennial if planted that late in the season. Enjoy them while you have them.
However, there are varieties that are truly perennial in most climates. Their hardiness, plus their ability to be pinched back during the summer so they won't bloom until fall, make these jewel-toned beauties a welcome splash in the garden when most summer flowers have begun to fade. Bloom times vary with variety and climate, from early September through mid-October.
Mums come in multiple flower forms, although many varieties are hard to find and need to be specially ordered. Mums come in every color but blue and the blooms last for weeks, even when cut. Here are some more commonly found varieties:
- Anemone: One or more rows of petals with a cushion-like center
- Pompom: Familiar globular shape
- Regular Incurve: Petals curve up and in, forming a sphere
- Single or daisy: Looks like its cousin, the daisy
- Spider: Long, curled petals droop down and give a spider-like look
There are also shorter, mounding varieties of mums generally grouped as ‘cushion’ mums.
Mums, Garden Mums, Hardy Mums
Hardiness varies by variety and growing conditions. Most established mums will be hardy from USDA Hardiness Zones 3 - 9.
Late summer/fall. Pinching the stems until about July 4th will give you more branching and buds, and the plants will bloom later in the season.
Mature Mum Size
Again, this will vary greatly depending on the variety grown, sun exposure, and other growing conditions, and whether the plants are pinched back. Most varieties are listed as growing somewhere between 4 - 36 inches (h) x 12 - 36 inches (w).
Although mums can handle partial shade, you will get the fullest plants and the best blooms in full sun.
Using Mums in Your Garden Design
Since mums bloom so late in the season, they are going to be a non-descript, though not unattractive plant in the border. Plant them next to early bloomers. As these spring blooming flowers fade, the mums will fill in and hide their unattractive fading foliage.
While mums make a wonderful impact in containers, they will end your garden season with a bang when paired with other late season bloomers like sedum, goldenrod, Russian sage, asters, gaillardia and the changing foliage of ornamental grasses.
Suggested Chrysanthemum Varieties to Grow
You will rarely find named mums in garden centers. To obtain the exceptional varieties or exhibition mums, you will need to order from a nursery, a specialty mail-order company, or start from seed.
- Chrysanthemum ‘Clara Curtis’ - Rubellum Group (hybrid) Long-lasting, early season, single or semi-double pink flowers
- Chrysanthemum ‘Mary Stoker’ - Rubellum Group (hybrid) Early season, apricot yellow single flower heads.
- Chrysanthemum ‘Apricot Moneymaker’ - Mid-season Anemone style with bronze petals
Tips for Growing Hardy Mums
- Soil: All mums prefer a rich, well-drained soil, with lots of organic matter worked in. They like a soil pH slightly on the alkaline side.
- Planting: To get the best variety, you will need to start your mums from seed. Start seed indoors, 6 - 8 weeks before your late frost date and harden off plants before transplanting outdoors.
You should be able to find plants in the spring if you look hard. They may not look like much then, but they will establish well and be knockouts in the fall.
Mums need at least a half day of sun for good bloom, but full sun is best. Mums set buds in response to day length, so avoid confusing them by planting where they may be exposed to bright nighttime light from a patio or window.
Caring for Your Mum Plants
To promote a sturdy, bushier plant with lots of blooms, pinch off the top 1 to 2 inches of growth once taller varieties are at least 6 inches high; shorter varieties, 4 to 5 inches high. Continue pinching the tips every 3 - 4 weeks until early July in cooler climates, the end of July in warmer zones.
These plants are heavy feeders. Starting with a rich soil and feeding every 3 to 4 weeks until buds set will improve flowering.
Deadheading is only necessary for warmer climates, where the plants remain green throughout winter. In other areas, the plants will probably be hit by frost before the flowers fade.
In areas that experience freezing winters, allowing the old foliage to remain until spring helps the plant’s survival. During cold, snowless winters, mulching will be necessary. Even then, there’s no guarantee all your mums will make it, especially those planted in the fall.
If mums have not been hardy in your area, you could try potting them and move them to a more protected area of the garden for the winter and return them to their intended spot in the spring.
Established mums can be dug and divided in spring, every 2 to 3 years as necessary.