how to plant, grow & care for chrysanthemums
complete growing guide
Chrysanthemums can be annual, hardy perennial or tender perennial, but we sell the so-called “florists’ chrysanthemums” that have been bred from the Chinese and Japanese types to make excellent late season cut flowers. They are generally tender and need to be brought into the greenhouse out of the wind and rain so that they flower right up to Christmas. They come in a wonderful range of rich velvety colours, with shapes that vary from the neat pom-pom to the outrageous spidery forms of ‘Tarantula Red’. We sell our chrysanthemums as rooted cuttings or larger potted plants and they are easy to propagate yourself should you want to increase your stock and insure against a hard winter.
details
- Common name: Chrysanthemum
- Latin name: Chrysanthemum
- Type: Tender Perennial
- Height: Up to 1.5m (5ft)
- TLC rating: Tricky
- Aspect: Sunny, sheltered spot
- Planting position: Back of the border or in the greenhouse
- Suitable for pots: Yes
- Good for pollinators: Some varieties
- Good for cut flowers: Excellent
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how to grow chrysanthemums
where to grow chrysanthemums
Soil type: Moist but well drained fertile soil is best for chrysanthemums.
Aspect & position: Choose a sunny and sheltered spot outside or grow in the greenhouse or polytunnel.
when to plant chrysanthemums
Our chrysanthemums are sent out in sets of rooted cuttings in spring or potted on plants a bit later. If you have a greenhouse or cold-frame, get the rooted cuttings in early spring and pot them on straight away in March and February. If not, it might be wise to get them as plants in early summer and plant them out between May and July.
how to plant chrysanthemums
planting early-flowering chrysanthemums
(e.g. ‘Allouise Salmon’ and ‘Pandion Bronze’)
These varieties are usually grown in pots or borders outside and should flower in the autumn. You can also grow outdoor varieties under cover (see below) which should give a longer harvest of flowers than growing them outside. If you have received rooted cuttings, pot them on as soon as possible into 7cm pots using a good quality, multi-purpose, peat-free compost. Water well and place somewhere frost-free with lots of light - a greenhouse or cold-frame is ideal.
planting out
Your chrysanthemums will be ready to go out into the garden when the roots have filled the pot, or around mid-May (along with the potted plants that we sell). Choose a sunny, sheltered spot with protection from strong winds and well-drained but fertile soil, that has had some organic matter dug in. Push bamboo canes into the ground at 30-45cm intervals and plant one chrysanth next to each cane.
planting late-flowering chrysanthemums
(e.g. Avignon Pink, Bigoudi Red, Pip Salmon, Pip Sunny, Rossano Elizabeth, Spider Bronze, Spiro White, Spiro Yellow, Tarantula Red, Tula Carmella, Tula Improved, Tula Purple, Tula Zoraya)
These chrysanthemum varieties should ideally be grown in a greenhouse, polytunnel or very sheltered southerly garden - where they will then flower from late October until Christmas, but at Perch Hill (East Sussex), we grow them outside and usually go on picking them into December.
planting out
If you have soil beds in your greenhouse or polytunnel, the rooted cuttings can be planted as soon as you receive them, spaced at 30-40cm intervals and watered in well. Alternatively, you can grow your chrysanths in large pots (about 35-40cm in diameter), to move outside in good weather, or even sink into the flower border. Fill the pots with a peat-free, multi-purpose compost and plant one rooted cutting per pot. Water in well.
Provide support by inserting a stake at their side, tying them in as they grow. Water freely throughout the summer and give them a balanced liquid feed every two weeks from midsummer until the buds start to appear. Pinch out or disbud if required (see below). If you have moved your pots outside, be sure to bring them back if gales or frosts are forecast. We often move ours in to replace tomatoes in the greenhouse.
how to care for chrysanthemums
staking
Chrysanthemums, like dahlias, tend to break at the base of the stems so staking is key. By the time your chrysanths are at their peak height, autumn gales and rain will be on the way too. The stakes should be tall enough to accommodate the plant, but short enough for the flowers to stand proud of it; check the height of the varieties you have purchased.
At Perch Hill, we tie them in individually to their own cane, or grow a whole bed up through netting stretched horizontally with the first horizontal layer at about 18in from the ground and a second at 45cm. Water generously after planting for 1-2 weeks to help plants get established. Feed once a month using a balanced liquid feed.
pinching out & disbudding
As with almost every plant you grow for picking, you want stocky, stout rugby players rather than spindly athletes. So once they reach 15-20cm, we pinch out our chrysanths, removing the top growth and taking it down to three or four leaves up from the base of the plant. This promotes the formation of side shoots and you'll create a bushier, more flower-productive clump, you can also use what you remove as cuttings (see below).
If, on the other hand you want to encourage one large flower, you will need to disbud. This is a similar technique to training tomatoes – removing all the side shoots as the plant grows to create a single strong stem.
overwintering
Chrysanthemums tend to come to their peak just as the weather starts to get wet and windy, so if you have been growing them in pots outside it is best to bring them into a cold greenhouse or polytunnel to see them through the winter.
At Perch Hill we bring them into the greenhouse and sink them in the same bed that the tomatoes have been growing in. The tomato vines are pulled out, beds dug over and we add a bit of manure, and then plunge the pots of chrysanthemums into the soil and they carry on flowering into Christmas. We water them and that's all they’ll need - it couldn't be easier. We can pick these to our hearts’ content right the way through winter.
taking chrysanthemum cuttings
Chrysanthemums are one of those plants where the younger the stock the better the growth rate and flower density. That's why it's important to take chrysanthemum cuttings rather than relying on last year's plants. Chrysanthemum cuttings could not be easier to do – the technique is the same as for dahlias – and for every mother plant, you can produce at least 10 of a new generation.
Most chrysanthemums, indoors or out will have started to shoot in April. With a sharp pocket-knife remove a few of the burgeoning stems, 5-7cm long, from as near the base of the plant as you can. If your cuttings are longer than this, just use the shoot tip but remove the bud at the top. This encourages energy to go into developing roots, rather than top growth. Push them into a gritty mix of compost, four or five to a medium-sized pot around the outer edge. I don't bother to use hormone rooting powder – they seem to root well without.
Place the pots out on sand or capillary matting so they can absorb water from below. If you have one, put them in a propagator or on a heated mat so they get a bit of bottom heat. This speeds up the rooting. Keep the compost moist at all times and they should root in three to four weeks. Pot them up individually when you see roots through the hole in the bottom of the pot. Use 7 – 9cm pots of peat free multi-purpose compost and keep them somewhere light and frost-free. They will have filled their pots and be ready to go out into the garden in mid-May.
seasonal checklist
spring
- Pot up rooted cuttings as they are delivered into 7cm pots.
- Pot on into 1 litre pots if planning to plant outside, or into greenhouse beds.
- Pinch out young growth to make stocky plants.
- Take cuttings using young growth.
summer
- Plant out either into large pots or into final position outside.
- Water and feed every fortnight
autumn
- Start to harvest early varieties.
- Move pots under cover once autumn winds and rain threaten the flowers.
winter
- Continue to harvest later varieties.
pests, diseases & common issues
aphids
There is an aphid for every plant, it seems, and chrysanthemums are no exception. The key is to catch them early before they start to multiply. Squash the little brownish bugs that are feeding on the leaves, and consider using a biological control like encarsia wasps if you are growing them in the greenhouse.
spider mite
This is likely to be a pest in a hot dry greenhouse, and these microscopic spiders are hard to spot until they start to build up. Occasionally you will spot silvery webbing under the leaves, so the natural predator phytoseiulus persimilis will then need to be brought into help.
chrysanthemum rust disease
There are two types of fungal rust disease that affect chrysanths: white and brown. The white rust is more serious and you need to remove and destroy any leaves that are developing dimples of pale dust on the top surface. Humidity and warmth is a common cause, so ensure your greenhouse is well ventilated and avoid overhead watering.
chrysanthemum leaf spot
Chrysanthemum leaf spot is caused by bacteria rather than fungus, with leaves turning blotched and brown. The preventative methods are however the same, ventilation being the key.
chrysanthemum stem necrosis virus
In case fungus and bacteria are not enough, we can add virus spread by thrips to the list of ailments, but thankfully this is a rare one, and has indeed been eradicated in the UK!
chrysanthemum powdery mildew
Another fungal disease which creates a white dust over the whole leaf. Remove and destroy affected leaves and increase ventilation in the greenhouse.
chrysanthemum nematodes
Microscopic worms that burrow through the surface of the leaves, leaving yellow brown spots in their wake as they move up the plant from the soil where they overwinter. Mulching the plants will help prevent their emergence, and changing the soil might well be necessary.
why are my chrysanthemums not flowering?
Chrysanths are a late flowering species, so you will need to be patient. Don’t give them too much nitrogen rich food, a well-balanced potash feed such as liquid seaweed is what they need.
why is my chrysanthemum dying?
Depending on the time of year, this could just be the plant’s natural cycle of losing its leaves in readiness for winter dormancy. If this happens in spring or summer then it could well be suffering from drought or even over watering. Take a look at the leaves and check them out for any of the symptoms listed above.
why are my chrysanthemums turning brown?
If the whole leaf is turning brown, this is likely to be a sign of stress caused by drought or over-watering. If it is a brown spot or pustule this is more likely to be a fungal or bacterial attack, so remove the affected leaves and destroy.
why are my chrysanthemums wilting?
If it is in a pot, check that the compost is not too dry or wet. If that is not the problem, turn out the plant and look for little white grubs in the soil – vine weevils are particularly partial to chrysanthemum roots, and wilt will be the first sign of root damage.
There is also a disease known as Fusarium wilt which could be present, but very unlikely in certified stock.
frequently asked questions
are chrysanthemums perennial?
Yes, the cut flower varieties that we grow are perennial. There are annual chrysanthemums, but they have been recently renamed as Glebionis (crown daisies and corn marigolds) and they would be sold as seed.
how do you take chrysanthemum cuttings?
In April, when the plants start to shoot, remove a few from near the base of plant with a sharp knife. Put the 5-7cm cuttings around the edge of a small pot of gritty compost. With a little bottom heat they should root in 3-4 weeks, after which they can be potted into individual 7cm pots to grow on.
are chrysanthemums poisonous to cats?
They can be toxic to cats, but most animals are clever enough to avoid anything that is harmful to them. If your cat starts vomiting and you notice the flowers or leaves have been eaten then best to visit the vet.
are chrysanthemums hardy?
There are some hardy varieties of garden chrysanthemums (mostly renamed leucanthemums now), but the plants we sell are much better moved under cover for the winter months.
do chrysanthemums flower every year?
Yes, as long as they have been well fed and watered in the previous year, they should flower for you every year.
do chrysanthemums repel mosquitoes?
Chrysanthemums contain the chemical pyrethrin which is used to kill fleas and other insects, it will also repel mosquitos. However, you would have to dry the flowers, grind them up and extract the oils for that to work – growing them alone will not work I’m afraid.
how often do you water chrysanthemums?
They are thirsty plants as they are quite shallow rooted, so if you have them in a pot or glasshouse where they cannot reach a large area of moist soil they will need watering daily in the heat of the summer. Once the weather cools, once a week should be sufficient.
will chrysanthemums survive winter?
They will, as long as they have protection from the cold and wet. Move to an indoor space such as a greenhouse or polytunnel as soon as frost is forecast.
where do chrysanthemums grow best?
They prefer a really sunny sheltered spot, out of strong winds and rain – so a greenhouse or polytunnel is best for most chrysanthemums.
how do you keep a chrysanthemum alive?
Like all plants, chrysanthemums need water, light and food. So, a monthly liquid feed is very important if you have them in a pot. They also need warmth to flower well, and shelter from the worst of the winter weather, move them inside as soon as frost is forecast.
can a chrysanthemum be planted outside?
We grow two varieties that are very happy outside: ‘Allouise Salmon’ and ‘Pandion Bronze’. However, it does depend where you live. Here at Perch Hill in Sussex, even the more tender late flowering varieties are still happy outside in November and even into December. Really it is best to plant them in pots which can be moved outside for the summer and early autumn, then brought indoors for the winter.
are chrysanthemums toxic to humans?
Sometimes the sap can irritate the skin, but they are not majorly poisonous. Indeed some chrysanthemum flowers have been used as a tea in Chinese medicine for their anti-viral properties, but regular consumption is not advisable.
how to cut & arrange chrysanthemums
Chrysanthemums are probably the longest lasting cut flowers you can grow – often looking good for up to a month, particularly if you arrange them singly in a vase and regularly remove the bottom inch of stem. They are also probably the latest to flower in the season – we can still be cutting them at Christmas just as the Paperwhite Narcissi are coming into flower. The whole spidery group (e.g. the Tulas) look fabulous with heads cut on a short stem and floated in a large bowl, or cereal bowls down the centre of your table. Even cut like this, the flowers last over a week.
Get more inspiration for displaying your flowers with our flower arranging videos:
