‘This often maligned flower is truly elegant and the essence of autumn’

Carolyne Roehm

In my last post I used a number of chrysanthemums that I had cut from my greenhouse for my Monday Flowers and I promised that I would write in further depth about how I grow these lovely autumn beauties.

I started growing indoor chrysanthemums about 6 years ago and as my space is limited I certainly cannot hold myself out as an expert grower. In fact I have to admit that I found the expert growing advice available online quite daunting and it has taken me a few years to develop confidence with these flowers. Much of the advice available is very technical, referring to stopping and disbudding techniques and incurving, reflex and ball varieties. There is little in the dry growing advice and somewhat limited images available online to fill a flower lover such as myself with the enthusiasm to grow chrysanthemums. I have to say that my initial impressions were that they were similar to growing oversized vegetables and I do not have the time or inclination to follow that particular hobby (although I do enjoy seeing the results of the endeavours of dedicated growers on Gardeners World). It was in a book called A Passion For Flowers by Carolyne Roehm that I first saw chrysanthemums displayed in beautiful arrangements and was inspired to have a go at growing them myself – I have been hooked ever since.

As with many things, in reality chrysanthemums are actually very simple. You buy a cutting, put it in a pot or the ground and in late summer and early autumn it flowers. In a nutshell that is it, although there are a few tips I can share to make sure you get plenty of flowers.

The first thing to note is that the chrysanthemums we are discussing here are those that are designed to produce late flowers and consequently are best brought under cover in autumn. These are not border chrysanthemums. There are a few very late ones that can only be grown under cover, but most of the late flowering varieties will flower perfectly happily outside although the blooms will suffer if the autumn is very wet and windy. These chrysanthemums also tend to flower earlier if left to grow outside. Ideally if you would like to grow late flowering chrysanthemums for flowers in November and December as I do, make sure you have a greenhouse, poly tunnel or a very sheltered growing area outside.

To start your collection rooted cuttings can be ordered from suppliers for delivery throughout the spring and summer, although I have the greatest success with cuttings that arrive in the spring.

When your cuttings arrive plant them in small pots and keep them under cover and well watered. When your little cuttings reach about 6-8 inches in height pinch them back to about 3 or 4 leaves from the base. The timing of this will depend on when your cuttings arrive, but I expect to do it some time in May or early June. Pinching out will promote side shoots which will give you more flowers.

Once they are growing well increase the pot size and keep them under cover until after the last frost. They can then be potted on again – I like to use 5L pots for the final move. After re potting plant them out in a well prepared bed in their pots. I have a section in my vegetable garden that I use to grow chrysanthemums and I dig in plenty of garden compost before I plant the cuttings out in their pots around mid June.

Once your cuttings have been planted outside you just need to make sure that they are watered regularly and staked as they grow in height. Some varieties can get to over a metre so, like dahlias, they need staking to stop the stems from breaking. I like to feed mine with a seaweed feed every two weeks or so to keep them growing well. Towards the end of August I pinch them back again, just taking out the top few inches of growth to stop them producing early flower buds. It is perfectly fine to miss out this stage but it will mean your chrysanthemums will flower earlier.

Assuming you have indoor growing space move your chrysanthemums under cover in early October. They follow on nicely from tomatoes which are normally cleared away towards the end of September. If you have a growing bed dig it over and add plenty of compost. Otherwise the chrysanthemums can be left in their pots.

Ideally choose a fine day and dig all the chrysanthemums up that have been growing outside – you can see now why I advised that you plant them out in their pots. They are easier to dig up and there is less stress on the root system if they are contained in a pot. Be very careful with this stage – damaged stems now will reduce your crop. Take them all under cover and either arrange them on the floor/staging of your greenhouse or dig the pots into the greenhouse bed. In both cases water well. Continue to water and feed your chrysanthemums regularly to keep them growing healthily. You can buy proprietary feeds but I prefer to use a seaweed feed as I try to choose organic options wherever possible.

You should have your first flowers by early November and you can expect them to go on flowering until mid December or later depending on your choice of varieties. If you are keen to have very large blooms nip out any smaller buds growing around the central bud. As you can see from the flowers below I tend to leave them as I am not looking for exhibition blooms but rather just something pretty to bring inside in these late months of the year. I also love walking into my greenhouse when it is bulging with chrysanthemums – it is a feast for the eyes and spirit on dank, dark days.

When you cut chrysanthemums for arrangements do not take any longer stem length than is necessary for your chosen vessel. New buds will often be forming underneath your first flowers and these will go on to bloom in a few weeks time if you do not cut back too far. Once inside chrysanthemums have a long vase life. If you re cut the stems every 3 days or so they will carry on for a couple of weeks. I tend to move them into shorter vessels as the stem length gets shorter, often ending up with single blooms in small bottles.

Once your chrysanthemums have finished flowering, or in my case when I need the space to plant out my indoor sweet peas, dig the pots up and cut back all the stems to about 4 inches. Store them somewhere frost free and dry – I put them in a shed or under the staging in the greenhouse. Even if you have left your chrysanthemums to flower outside the advice is to dig them up and store them somewhere frost free for the winter as they are not reliably hardy. As I don’t grow these varieties outside I have no experience to comment on whether this is right.

Once stored you can ignore them until early March when you will start to see new shoots. At this point repot them all into fresh compost or use the new shoots as cuttings and start again in small pots. In either case they will need to be kept frost free until after the last frost when, like dahlias, they can go outside again.

The choice of chrysanthemums is large and with only limited space to grow them under cover I have to be frustratingly restrictive about the numbers that I grow. Over my growing years I have ordered cuttings from Sarah Raven, Chrysanthemums Direct and Woolmans. By far and away my favourite variety at the moment is Avignon – I love the peachy pinky nude colouring which is so like dahlia Cafe Au Lait. I love to grow white chrysanthemums as they work so well with christmas themes in December and I would not be without Allouise Orange which is a perfect shade to mix with autumn pumpkins. I love the Boulou series for their dishevelled looks and the American Beauty series is also a favourite although I could not find any photos to share with you. Next year I plan to grow Allouise Orange, Salmon and White, Boulou White, Sarah Ravens Raspberry Ripple collection which looks delicious and, of course, my favourite Avignon again.

I hope that you have found this helpful and that I have inspired you to think about growing some chrysanthemums in your greenhouse next autumn – if we have the space why not use it to grow beautiful flowers! I will be back on Monday with some more Monday Flowers and also a little giveaway for you to enter as a welcome to the festive season.