by Denise Bonomo
The bright blooms of chrysanthemums make them an autumn favourite. A multitude of “mums” in various colours can be found outside of grocery and department stores starting in late summer. People plant them in their gardens and planters to brighten these spaces as summer blossoms begin to fade. They are usually planted as fall annuals, then composted just before the snow flies.
But Chrysanthemum x morifolium is hardy in Zones 5-9, so it can be planted in spring as a perennial. In the colder range, they are best planted in a sheltered area. Because they can suffer from stem and root rot, especially if planted in low areas which tend to be damp, it is best to level the soil around them with compost and cover them well with evergreen boughs for the winter.
Two thousand years ago, when Confucius first wrote about mums, they were described as a simple golden flower. These days, hybrids include many dramatic harvest shades including gold, orange, pink, purple, burgundy and white.
The chrysanthemum is an ancient plant of the family Asteraceae (Compositae). This is the largest family of flowering plants with 1,500 genera and 23,000 species. With a quick glance, their composite flowers seem like one large flower. In fact, they are complex and highly specialized. Take a closer look and you will see they are made up of many florets, each of which can produce seed. Each ray, which looks like a petal, is a floret and the center disk is made up of many tiny florets.
In the fourth century, Buddhist monks carried chrysanthemums to Japan where they were made part of the emperor’s crest and a symbol of the royal family. It is thought that they were introduced into North America in the 1800s, although there is an indigenous variety, C. arcticum, the Arctic daisy.
When spring chrysanthemums become available in nurseries, select ones that are bushy and have green leaves and tight buds. Yellow leaves indicate overwatering. Prune back a third of the stems before planting. Mums prefer full sun, at least five hours a day, and well-drained soil that contains organic matter. They will grow in partial shade but will tend to get leggy. When selecting a location, also consider nighttime exposure to light. Chrysanthemum bloom occurs in response to shorter days and longer nights, so avoid areas that are flooded by street and other types of security lights.
When ready to plant, dig a hole twice as wide as the root ball but not very deep. Spread the roots out and cover with soil to the growing point where the stem and the roots join. Do not bury any of the stem. Mums have shallow roots so plant them at least 45cm apart. They do not compete well with other plants for moisture but do require lots of water. It is best to use drip irrigation or a soaker hose. Watering in the morning allows foliage to dry off through the day. Mums are prone to mildew, so air circulation is also important.
To ensure short, full plants by fall, pinch back or prune the stems to about 15cm in the spring and early summer. Stop this about 3 months before you expect the plant to bloom. Following this practice can double the number of buds on the plant.
If you would like to have chrysanthemums for cut bouquets, remove all the side buds throughout the growing season to encourage one central bloom. When ready to cut, use a shape knife and cut on an angle. Morning is the best time to cut blooms, as the plant will be most hydrated. Remove any leaves that would be under water. Set the stems away in a cool dark space to rest overnight. Add a small amount of a balanced soluble fertilizer weekly. Following these instructions will allow you to enjoy the blooms for 3-4 weeks.
Propagating chrysanthemums can be done by seed, cuttings or plant division. Seeds will give you more mums but not likely the same colour – hybrids do not “come true” from seed. Dividing plants from friends, neighbours or nurseries is the fastest, simplest way to get new plants and they will be clones of the original. In spring, when new growth appears, dig out the mature plant, shake off the soil and then cut between the stems, gently pulling them apart. Make sure the roots stay attached. Throw away old woody parts. The new plants can be planted directly into prepared garden beds or into pots or planters.
Do note that some of the more exotic looking chrysanthemum hybrids are patented and cannot be propagated without permission. If you are purchasing plants from a nursery, check the plant label.
Chrysanthemums will grow with fairly little attention. If you nurture the plants with proper distancing, watering, lighting and pinching however, you will be rewarded with a bounty of beautiful blooms each fall.
Side Bar:
The Fall Garden and Mums Show has been taking place every October in Hamilton, Ontario, for 101 years. The event is located at the Gage Park Greenhouses where some 200 varieties of chrysanthemums and more than 100,000 blooms are displayed by the City of Hamilton’s Horticultural staff.
The Mills China Shop in Hamilton was one of the first shops in North America to sell English fine bone china. The shop earned such a reputation that FD Roosevelt’s mother travelled from Washington to Hamilton to purchase dinnerware for the White House.
In the early 1950s, to celebrate the 25th anniversary of the Mums Show, Mills partnered with Paragon China in England to design and produce a pattern of dishes named Mums. My own mother selected this pattern for her wedding trousseau in 1952. I am pleased to use this heritage china for my family celebrations. It brings back fond memories of dinner parties and Sundays at my childhood home in Hamilton.
(Denise Bonomo is a retired public health nurse and an avid perennial gardener. She volunteers with the Master Gardeners of Ottawa-Carleton.)