Kiku and Mum: The Japanese Chrysanthemum That Left Home and Came Back
In autumn, Japanese garden centres fill up with chrysanthemums. But look at the price tags and many of them say "mum": pot mum, garden mum, spray mum. Is it a chrysanthemum or not? Do you grow it the same way?
The short answer is that it is the same plant. It is a Japanese flower that travelled abroad, changed its shape, and came back home under a new name.
We are a small tree care and landscape business in Mie Prefecture, central Japan. This page explains what the chrysanthemum means in Japan, how it left and returned, and one thing about it that matters in an ordinary garden at night.
Why the chrysanthemum is special in Japan
In Japanese the flower is called kiku. It is the flower of the Imperial family's crest, and a chrysanthemum crest is also printed on the cover of the Japanese passport.
The plant came to Japan from China around the Heian period, more than a thousand years ago. In China it had been grown for medicine and food. Japan also adopted the Chrysanthemum Festival on the ninth day of the ninth month, a day for wishing for good health and a long life.
From the early Edo period, growing chrysanthemums became a passion. Gardeners bred many new varieties and displayed them in shows, and even made life-size dolls dressed in living chrysanthemum flowers, called kiku-ningyō. Autumn chrysanthemum shows are still held across Japan every year.
One thing visitors should know: white chrysanthemums are the standard flower for graves and Buddhist altars. Because of this, some people in Japan feel a bouquet of white chrysanthemums is not a cheerful gift.
The year it left, and the year it came back
Chrysanthemums reached Europe in 1789, from China. For several decades they did not become very popular there.
The change came in the 1860s. The British plant hunter Robert Fortune visited Japan in 1860, and in 1861 he sent a range of Japanese varieties back to Britain. Chrysanthemum breeding then spread across Europe. Fortune is best known for taking tea plants from China to India, and he wrote that he was surprised to see ordinary people in Japan, of every class, enjoying flowers.
In the 1940s, a new type was developed in the United States. Instead of removing side buds to grow one large flower on each stem, it was allowed to branch and carry many flowers at once. This is the spray mum.
Spray mums came to Japan by way of Europe in 1974. The first place to grow them was Toyokawa in Aichi Prefecture. They need less work and a shorter growing season than single-flowered chrysanthemums, and they spread across the country from there.
Why "mum"?
The botanical name is Chrysanthemum. "Mum" is simply the end of that word. It comes from Greek: chrysos, gold, and anthemon, flower. Together, the golden flower.
In Japan, the old native types are called wagiku, Japanese chrysanthemums, and the types improved abroad are called yōgiku, Western chrysanthemums. A pot labelled "mum" in a Japanese shop is usually a yōgiku.
So many flower shapes
What makes spray mums fun is how different the flower shapes are from one variety to the next. The US National Chrysanthemum Society sorts them into thirteen classes. Five that you often see in Japanese shops:
Single: a flat disc in the centre with one or more rows of flat petals around it, like a daisy.
Anemone: a raised, cushion-like centre with a single ring of flat petals.
Decorative: the centre is hidden. The upper petals curve inward and the lower ones turn back.
Pompon: a small, neat ball of regularly curved petals.
Spoon: thin tubular petals that open into a small spoon shape at the tip.
Because one stem carries many small flowers, a single stem of cut spray mums already makes a generous bunch. They also dry well.
Now, the garden part
The chrysanthemum is a short-day plant. When the days get shorter and the nights longer, the leaves sense it and the plant starts to form flower buds. That is why it blooms in autumn.
The interesting part is this: if you shine a little light in the middle of the night, bud formation stops. This is called a night break. Light a lamp at midnight and the chrysanthemum does not register that a long night has come.
Growers in Aichi Prefecture turned this into a technique. They light their greenhouses at night to delay flowering, then switch the lights off when they want the flowers to open. This lets them ship flowers steadily all year round, and Aichi is still the top shipper of spray mums in Japan. On the Atsumi Peninsula, a long, narrow peninsula in Aichi, the lit greenhouses glow across the dark fields at night. The view has been recognised as one of Japan's Night View Heritage sites, and local hotels even run night tours to see it.
Now back to the home garden. Under the porch light. Beside the front door. Along a path lit by a security light. Many gardens have places that stay bright at night.
In theory, a chrysanthemum planted there may struggle to form flower buds. It grows, but it never flowers. Japan's Ministry of the Environment notes that night lighting can affect crops, though the examples it names are rice and spinach, not chrysanthemums. How much a porch light really affects a garden chrysanthemum has not been tested. Still, if your chrysanthemum will not flower, check how bright that spot is at night before you blame fertiliser or sunlight.
The same guidelines contain a line that matters to us as tree workers: street lights placed close to trees and plantings may delay their growth and their leaf fall, and late leaf fall can weaken a tree. For plants, light is food, and it is also a clock.
One tip for cut flowers
The Aichi agricultural cooperative suggests breaking the stems by hand to the length you want, rather than cutting them. The rough, uneven break takes up water more easily. Remove any leaves that would sit in the water, and change the water about once a day.
It is a little strange for people whose work is holding pruning shears to say this, but for chrysanthemums, breaking is better.
Two directions of care
The large wagiku at an autumn show and the small mums in a garden centre pot are, at their root, the same plant. One was trained to carry a single flower on each stem, its side buds removed again and again. The other was allowed to keep its buds and fill every branch tip with flowers.
People simply turned their care in opposite directions, and the plant became two very different faces. We think trees are the same. The same species can look completely different after twenty years, depending on who cared for it and how.
