Mums vs. Asters and How To Use Them in Your Landscape

Mums and asters are synonymous with fall flower gardens. Late summer rolls around, and these show stoppers begin to trickle into garden centers. By the first day of fall there are enough options available to wash gardens and landscapes in a flood of rainbow colors until winter comes to end the party. Contrary to the now-popular habit of enjoying the blooms then dumping the plants when they die down with cold weather; many are hardy varieties that can have a permanent home in your landscape to enjoy year after year!

Mums vs. Asters

Chrysanthemums, or mums, include over 200 species of the aster family. So all mums are asters, but not all asters are mums. The garden mums that are so popular today were derived from species and hybrids originating and first developed in the Far East. Their bloom cycles are triggered by the shortening length of daylight hours, that is why they naturally bloom in fall. Different varieties are triggered to bloom at different times, so it is best to consider this when making purchasing decisions: several of a single variety for a big show all at once or many different types for a longer show. Mums bloom in lavender, pink, white, red, orange, bronze or yellow tones.

How to Grow Mums and Asters

Plant chrysanthemums in a sunny location, with consistently moist (not wet) well-drained soil. Heavy clay or sandy native soil should be amended with compost to improve the texture. Plants should be mulched well and watered as needed through the hot weather, because the shallow root system can quickly dry out. Fertilize once or twice through spring and summer to promote growth and good bud set, and pinch the growing tips periodically to encourage branching and a compact habit. Stop pinching about 3 months prior to the variety’s bloom time to allow buds to develop. As flowers fade, remove them to foster reblooming. When flowering ceases, cut the plant to the ground for winter.

Most garden asters are derived from North American native perennials. Broadly speaking, they are hardy in zones 4-9, although individual varieties may be more restricted. As mentioned earlier, the aster family includes many genera such as mums; however what we know as “asters” were also a genus unto themselves...until botanists decided to give them new botanical names. Don’t worry, garden centers still call them asters. They all bloom in the late summer or fall. While you can choose from white, pink, purple or blue blooms, and plants that mature at 1, 2, 3 or more than 4 feet, all of the asters require similar growing conditions.

Asters perform best in six or more hours of sunlight. They should be planted in moist, well-drained soil of average fertility. Established plants require little fertilization, perhaps one application as they emerge in spring. Taller varieties may require staking as the summer progresses. Pinching some of the tips in early summer will delay the bloom of those stems. By pinching several times and leaving some stems unpinched, you can extend the bloom season by several weeks.

There are several ways to employ the benefits of mums and asters. They can be used in conjunction with one another, as the mums tend toward warmer colors and asters toward cooler colors, they make a nice contrast (consult your color wheel). Another contrast is in their growth habits. Mums tend to have a more “manicured” look, while asters have a wild appearance. Mums provide the color tones of autumn, which work nicely with harvest displays and plantings. Asters are a huge boost for late-season nectar feeders that have yet to migrate, or may be passing through.

Including mums and asters in your perennial landscape is an easy way to extend the flower season through fall. Make it easy on yourself and give them the permanent home they deserve.