At a glance
Latin name: Chrysanthemum ‘Gethsemane Moonlight’ 
Common name: Perennial mum
Family: Asteracea (aster family)
Plant type: perennial 
Flowers: 3” creamy yellow daisies
Foliage: mounding to sprawling habit
Mature height: 2-1/2 ft.
Hardiness: Zones 5a-9b
Soil: well drained
Exposure: full sun
Water usage: medium
Sources: mail order or local nursery

Whatever you call them — chrysanthemums or mums — they are synonymous with gardening in fall. Most of us are familiar with the garden mums sold in 6-inch and 1-gallon containers in every retail nursery in the state. Their perfectly round balls of flowers make them popular for quick garden decorating this time of year. But few gardeners are familiar with the old-fashioned "perennial" type chrysanthemums. Unlike the more common hybrid mums, these make wonderful garden plants. Hybrid mums were bred for culture in pots and not for garden performance; even if they do perennialize in your area, they never flower quite as well the second year, and the flowers all seem to appear at once and not last as long.

‘Gethsemane Moonlight’ and other perennial garden-type mums are super vigorous — and prolific bloomers in the garden. Plants will easily spread to 4 feet across and 2-1/2 feet tall, and the flowers start in mid-September and last until first frost. The spreading habit and fall flowering make it a natural for mixing with autumn blooming sages such as Salvia leucantha (Mexican bush sage). The creamy-yellow flowers mix wonderfully with any shade of blue or purple, or can help cool down hot oranges and reds in the garden. Make sure to plant in full sun and in well-drained soil. Perennial chrysanthemums are not particular about soil pH. If you would like to keep the plants more compact and keep them in bounds, just shear them occasionally until mid-summer, but don’t cut the foliage back after that or you will lose some of the fall flowers.

If you are not a fan of the pale yellow flowers of ‘Gethsemane Moonlight’, then try the darker color of ‘Autumn Moon’ or the peachy flowers of ‘Single Apricot’ or the bright pink flowers of ‘Celo Pink’ or ‘Country Girl’.