I first got two sets of chrysanthemums early last year, during the COVID lockdowns. I was working indoors, and the apartment needed a bit of glow. In the back section of Ralphs, there’s an area where sad and neglected plants are marked down, ready to be tossed away. I found two amazing specimens and decided they needed to live at home with me, to keep myself and the plants happy. (Side note – is there a place for neglected plant adoption?)
They are tricky to keep happy indoors. To keep light down on my computer screens, I often had to angle the blinds one way or another. These mums need light, and they started to get leggy during the dim days. Their blooms faded, and I was worried they’d die. I started to walk them outdoors each morning, then back in during the evening. I hadn’t learned about how forgiving they are of pruning, so I let them grow a little past where they would be happy. By wintertime, I had two stretched out chrysanthemums that were both alive and unhappy. I’m sure being picked up and carried daily isn’t something a chrysanthemum longs for.
Somehow, they lasted through winter. Both were moved out to permanent outdoor potting by fall, and I had pruned both to get rid of the worst old stems. They bloomed again in early winter, for whatever reason, and then one of them faded completely. Now, a little farther on in winter, I have one stretched out Chrysanthemum that I want to use to start new plants from cuttings.
Here’s to more big blooms!
They’re many different types of chrysanthemum, presenting with many different blooms and densities. Chrysanthemum is a genus that belongs to the aster family (Asteraceae) and has about 50 species. The most common is Chrysanthemum x Grandiflorum, which are frost resistant and suitable to live in the ground. On the other hand, Florist’s Mums are best if you want to grow them in a pot (where frost isn’t a concern).
Typically grown as annuals, but can some varieties can be encouraged to grow as perennials. Herbaceous, sometimes known as subshrubs.
Bushy, with many flowers. Tend to bloom in spring, but can be delayed to summer or fall. Stalks can alternatively be trained to provide one bloom at the end of each.
Most are from East Asia and China
Water the plants once the top 1″ or so of soil is dry. I’ve found they enjoy being drier indoors, and wetter outside – but not too much of a difference.
When watering, make sure to water until some runs out the bottom of the pot. If you have a catchpan or some sort of tray under the pot, dump it out after 10 or 15 minutes. This will help prevent the soil from re-absorbing all the fertilizer salts that get flushed out. (My balcony mum has no catchpan, and drains every time.)
Water under the leaves (as opposed to over the top of the plant). This will keep the chance of fungal infections down – mums are sensitive to high humidity.
When you’re first transplanting a store-bought chrysanthemum, the roots could be very tightly grown together. If this is the case, they may not soak up water very well, and a large portion could run off the sides and avoid the root ball altogether. If this seems like it’s happening, you can soak this entire root ball in some water for an hour or so before transplanting it. This will give all the roots a chance to drink, and soften up the dirt at the heart of it. Just be aware that leaving it sitting in water for more than a couple hours could drown the plant.
Chrysanthemums have a somewhat shallow root system, so the soil should be kept moist if anything.
If you’re growing them indoors, the best place is in a windowsill. Place them where they can get bright light for as much of the day as possible. Is 10 hours doable?
Outdoors, make sure they can get at least 5 hours of morning light and shade in the afternoon. I have mine placed on a corner of the balcony that’s lit morning-noon, then lets light into through 1.5″ slits for the rest of the day. It’s flowered twice this year!
Wherever the plant is while indoors, make sure it’s not getting light at night too. The plant is sensitive to light, and a strong street lamp may throw it off.
Hardy to zones 5 to 9, though some of the more delicate species won’t survive frosts. You can overwinter potted plants indoors in a sunny windowsill. Seedlings like to start off at room temperature.
These plants love fertilizer. I use a balanced slow-release mix that I add every 4 months.
If you have a liquid fertilizer, they can also be happy with a balanced mix (10-10-10) that gets added in small amounts every month during the growing seasons. Just make sure to flush the pot properly to avoid a buildup of harmful salts.
The plants doesn’t need fertilizer in winter.
Good quality potting soil with good drainage. Slightly acidic to neutral. Add a bit of compost to the hole to help them along when transplanting. They’re not all that picky about soil conditions, all things told.
When transplanting, plant your flowers at the same depth as they had been living at.
Root & Pot
When you buy chrysanthemums at the store, they’ll often be cramped together in a pot with regular soil. The best thing you can do is repot them somewhere larger, with better potting soil. Removing your chrysanthemum from its original pot should be pretty easy, as all the roots will be tangled together in a big bundle.
Growing chrysanthemums in pots does have the added benefit of mobility. It’s easy to move plants indoors to protect from frost, and outdoors to get light. I used to walk my mums by setting them outside on a table when I left for work, and bringing them indoors when I got home.
Chrysanthemums have a somewhat shallow root system, so they’ll dry up quickly in the zone where they live.
When moving rooted cuttings or small plants to their larger homes, space plants about 20 cm (8 inches) apart. Water them thoroughly so the roots can chase the water down and establish well. Alternatively, give each plant a 30 cm (12 inch) pot to fill in by itself.
Size & Speed
Cut back the foliage some during the fall when it naturally wilts.
You can pinch off stems when they get to about 5″ high, before they bud. Doing this can encourage bushier growth of the plant, and delay flowering. If you keep this up through spring and summer, you can even delay flowering all the way until fall.
Space plants about 8 inches apart when going into their long-term homes. Some species will need a bit more, but they should fill in quite nice like this.
If you’re working with cuttings, the best time to get them going is early spring. That way they’ll be ready to transplant for the heaviest part of growing season. Summer works as well, but it shortens the time for them to grow. Once the roots are going, move the cuttings to 7 cm (3 inch) pots and wait until the roots fill the small pots. Then they’re ready to move up.
To start from seed, get the seeds going 2 months before the last frost date. Cover them in 1/8″ of seed starting mix. Seedlings should emerge in 2-3 weeks. Get them plenty of light – a sunny spot windowsill or greenhouse, or 16 hours of artificial light. Keep them around room temperature. Transplant up to somewhat larger pots when seedlings have two pairs of true leaves.
Flower & Fruit
The flowers tend to bloom in spring, though they can be forced to bloom at other times by pinching off stems. They may also prefer to bloom in fall, when the shift from long days to shorter encourages the plant to change from vegetative growth to flowering growth.
Cut the flowers off after they wilt – it’ll help encourage the rest of the plant to flower and stay healthy. You can pinch off the end of stems as the year goes on to encourage the plant to become bushy and have many blooms. Alternatively, you can pinch off side blooms and cause each stalk to have a single bloom at the top.
These flowers require a lot of light to bloom, and may not bloom properly indoors. By controlling the light, you can decide when it blooms, or whether it blooms at all. If worst comes to worst, you can stick the plant outside for it to resume its normal blooming schedule.
They flower for 3 to 4 weeks, though some flowers may take a long time to fade.
Some species have white or yellow flowers that are used in tea. Others have leaves that are steamed or boiled for use in soups and other dishes.
Pests & Diseases
Grey mold, powdery mildew and root rot. Ensure your plant has proper airflow and doesn’t sit in water.
Leaf and stem miners, aphids, Chrysanthemum eel worm, caterpillars and worms.
The leaves and stems will get leggy in low light. The plant will have a ‘stretched out’ appearance, usually reaching towards the light. Leaves grow farther apart, and are generally weaker. The plant may not grow strong enough to support itself, and stems will hang low to the ground or over the edge of the pot (especially as they stretch to 2 feet in length!). Move the plant to light, and prune back the worst of the leggy sections.
Pruned portions of the plant can be easily composted… and even the entire plant if it’s doesn’t survive indoors. This happened to one of my chrysanthemums after about 9 months.
Categories: Growing Guides