Early Spring? Time To Sow Your Chrysanthemum Seeds And Follow These 5 Steps
Chris is a gardening writer and nature enthusiast. He graduated from Oxford Brookes University in 2022 with an MA in Psychology. Chris works with the Leeds Green Action Society, helping their food cooperative by growing various fruit and vegetables on their two allotments in Hyde Park, Leeds.
Reviewed By COLIN SKELLY
Colin is a Horticulturist and Horticultural Consultant with experience in a range of practical and managerial roles across heritage, commercial and public horticulture. He holds the Royal Horticultural Society’s Master of Horticulture award and has a particular interest in horticultural ecology and naturalistic planting for habitat and climate resilience.
Contributions From EMILY CUPIT
Emily is a Gardening Writer, Photographer and Videographer from Derbyshire, UK. She is the Founder of Emily's Green Diary - a community of more than 75,000 people who share in her gardening journey.
IN THIS GUIDE
There are tons of chrysanthemum varieties, each boasting bold and captivating colouration.
The shape and style of the flower changes between varieties as well, so spend time choosing the right one(s) for you before buying seeds.
There may be some minor variation between planting times and growing advice, depending on the variety you choose.
I would always recommend checking the instructions on each packet before starting – you can see on the variety I grew for this guide (C. segetum) that it can be sown under glass year-round, but only sown outdoors during limited months of the year.
Generally I would advise germinating indoors and then planting out – otherwise, yours might not flower before dying off.
Also be aware that chrysanthemum seeds can vary from their parent plant, and it’s hard to guarantee that the flower you grow will be the one you’re expecting.
Here’s an overview of the process:
- Sow indoors in late winter or early spring
- Keep seedlings in temperate conditions
- Transplant seedlings into pots
- Harden off indoor seedlings to ensure sturdiness
- Transplant outdoors and enjoy the show
Let’s take a closer look at how to grow chrysanthemums from seed.
| Difficulty | Medium |
| Equipment Required | Seed compost, seed trays, seeds |
| When To Sow | February to March |
| When To Plant | September to December |
When To Sow Chrysanthemum
UK conditions lend themselves best to sowing chrysanthemums indoors.
Sow in February or March, before the last frost.
If you have a heated propagator (ideally with light fittings) you will find it gives you a head start – so that your plant should flower even more profusely come late summer.
I started my seeds in early February and was not disappointed with how my plant turned out.
1) Sow Your Seeds
Put a layer of seed compost in your seed tray before planting your seeds.
You can see these are extremely small seeds – and be difficult to separate and divide into individual cells if using a seed starting tray.
Each seed needs to be about 0.5cm beneath the surface of the soil and you can do this by pushing the seed gently beneath the surface of the compost or by scattering them onto the top of the soil.
2) Provide The Correct Care
Chrysanthemum seeds will do best when kept between 18-21°C.
You can achieve this by keeping them in a room where you’re confident the temperature will stay within this range or by using an aforementioned propagator with a heated base.
You should thin out your seedlings when you notice multiple seedlings starting to sprout.
I actually used an eyebrow-plucker to navigate the sensitive seedlings, which can be easily disturbed at such a young age.
Leave the strongest-looking seedling in place, whilst removing any which are less developed or which have turned leggy in search of light.
3) Transplant Seedlings Into Pots
Seeds will sprout within a fortnight of planting and once they’ve sprouted, you need to transplant them into modules or small pots so their roots have space to thrive.
After, transplant to larger pots before planting; I moved mine into small compostable pots that were easy to transplant outside when May arrived.
4) Harden Off In Early May
To give your chrysanthemum seedlings the best chance of growing when you move them outside, you’ll need to harden them off first.
Take your pots or seed tray outside and leave it in a shady spot for a couple of hours.
The next day, leave it a little longer and repeat this for 7-10 days before planting out, gradually incorporating sunlight into their routine.
Mine were planted out in mid-May and although they took some time to establish themselves in their new environment, I experienced no ill effects given the last frost had already been and gone.
5) Plant Out In Late May
Once your chrysanthemums are hardened off you can plant them outside.
It’s recommended to do this in late May up to July.
Here’s the end result and my Chrysanthemum segetum (Corn Marigold) in flower, with many other buds ready to flower.
These were an absolute hit with the local insect population and at one point I must have counted between 15-20 flowers in bloom, from just one plant in a single day.
For best results, you should plant your mums into well-drained but moist soil.
I fertilised mine every week or two and it certainly seemed to help them flower in an area of the garden that only gets limited sun during mornings and early-afternoon.
