Key takeaways
- Celosia is a tender annual: frost kills it and cold nights hold it back
- Choose crested cockscombs, feathery plumes or slim wheat-type spikes
- Sow from March to mid-April at 21-25C in modules, not open trays
- A chill below about 10C can stunt young plants and make them flower tiny
- Plant out in early June into warm soil in your sunniest, most sheltered spot
- Strip the leaves from cut stems; the heads also air-dry with their colour intact
Celosia gives you flower heads like nothing else in a UK garden: velvet combs, feathery flames and slim pink spikes. It’s a fantastic cut and dried flower. The catch is that it loves warmth. Sow it warm, keep it warm, and plant it out late. This guide covers how to dodge the cold check that ruins most UK celosia.
Which type of celosia should you grow?
Garden celosias come in three forms. All are tender annuals that die at the first frost.
| Form | What it looks like | Best use |
|---|---|---|
| Crested (cristata), the true cockscomb | Dense folded velvet combs, like coral | Show-stopping cut flowers, bold bedding |
| Plumed (plumosa) | Soft, feathery, flame-shaped plumes | Bedding, pots, shorter cut stems |
| Wheat (spicata) | Slim spikes, pink or purple fading to silver | Cutting, drying, airy borders |
Wheat and plumed types cope best with UK summers outdoors. The big crested combs do best in a warm, sheltered spot or a polytunnel.
If you’re choosing between tender annuals for a cutting patch, the guide to growing gomphrena covers another everlasting flower that dries beautifully.
When and how to sow celosia seed
Sow from March to mid-April under glass at 21-25C. Celosia needs more warmth to germinate than most flower seed, so a heated propagator or the warmest spot in the house is best. On a cold windowsill, the seed usually just sits there.
The other rule: celosia dislikes root disturbance. Seedlings teased apart from an open tray often sulk and flower early.
- Fill modules or small pots with firmed, moist seed compost
- Sow two or three seeds per cell on the surface
- Cover with the thinnest dusting of vermiculite, as the seed needs some light
- Water from below and keep moist, not soggy
- Once seedlings appear, snip out the weakest at soil level
The guide to growing annuals from seed covers the basics of sowing under cover.
Sow a pinch of seed into each module so you never need to separate the roots later. Then keep them warm.
Are celosia plug plants easier than seed?
Yes. Buying plug plants in April or May skips the trickiest stages: the warm germination and the long, warm growing-on. If you have no heated propagator, plugs are the sensible way in.
Pot plugs up the day they arrive, keeping each rootball whole, then keep them bright and warm until June.
Pot plugs up the day they arrive into 9cm pots of peat-free compost, keeping the rootball whole. Grow them on somewhere bright at 15C or more until planting time.
How to grow celosia on without a cold check
Keep young celosia above 15C, in full light, and growing steadily. This is where most UK celosia goes wrong.
A seedling chilled below about 10C, even for a few nights, stalls and starts a flower head far too early. You end up with a stunted plant and a tiny button flower that never grows. Letting roots fill the pot does the same.
- Keep seedlings on a warm, bright windowsill or in a heated greenhouse. An unheated greenhouse is usually too cold until late May
- Pot on into 9cm pots as soon as roots show at the base of the module
- Water little and often, in the morning, and err on the dry side
- Give a half-strength liquid feed every week or two once they’re in 9cm pots
If a young plant does make a tiny flower early, snip it off straight away. Caught early, some plants branch again from below.
Same sowing, very different plants. The small one on the right was chilled and flowered too soon, which it can’t grow out of.
When can you plant celosia outside?
Plant out in early June in most of the UK, once frosts are over and the soil has warmed.
Harden off slowly over a week or two, more gently than with cosmos or marigolds. Start with a couple of hours outside on a mild day and bring plants in at night for the first week. Don’t leave them out when nights turn chilly. The guide to hardening off seedlings has the full routine.
- Choose fertile, well-drained soil in full sun, sheltered from wind
- Dig in some garden compost before planting
- Space bedding types 20-25cm apart and tall types about 30cm
- Water well and keep watering in dry spells for the first month
Flowers start in July and keep coming until the first frost.
Wait for warm June soil before planting. Cold ground stalls celosia just as badly as a cold windowsill.
Can you grow celosia in pots?
Yes. Dwarf plumed types were bred for pots. A 30cm patio pot takes three dwarf plants and flowers from July into autumn.
- Use peat-free multipurpose compost with a handful of grit
- Stand pots against a warm, sunny wall
- Water when the top couple of centimetres dry out
- Feed weekly with a liquid tomato feed once flowering starts
Don’t put pots out before June, as containers chill even faster than borders.
A warm wall makes all the difference. Dwarf plumes like these flower happily in pots right through to autumn.
How to grow celosia as a cut flower
Celosia is a brilliant cut flower that also dries well. Here’s how to get the best stems.
Spacing and support. Plant cutting rows about 15-20cm apart for longer, straighter stems. Put a layer of support netting at about 30cm over tall types before they reach it.
Pinching. Pinch plumed and wheat types once, when plants are 20-25cm tall, just above a pair of leaves. They then branch and give lots more stems. Leave crested types unpinched for one big comb, or pinch them for several smaller heads. The guide to pinching out cut flowers explains when it helps.
Harvesting. Cut crested types when the comb is fully formed and coloured, before it starts to shed seed. Cut wheat types when the lower half of the spike has coloured. Cut in the cool of the morning, straight into water, and strip off every leaf. The guide to conditioning cut flowers helps them last even longer.
Close rows and early netting give long, straight stems. A polytunnel helps the big crested combs most.
Drying. Bunch a few stems, strip the leaves and hang them upside down somewhere warm, dry and airy, out of direct sun. They dry in a few weeks and hold their colour for months.
Dried wheat celosia keeps its colour for months, so a summer of cutting brightens the house all winter.
Which celosia varieties grow best in the UK?
- Kimono series: dwarf plumes for pots, edging and windowsills, in cream to scarlet
- Century series: taller bedding plumes in scarlet, yellow, rose and cream
- ‘Dragon’s Breath’: dark red leaves topped with scarlet plumes
- ‘Flamingo Feather’: a wheat type with pink spikes fading to silver, great for drying
- Bombay series: crested cut-flower combs in rich colours
Celosia looks great alongside other warmth-loving cut flowers. Grow it beside zinnias and dahlias for buckets of colour from July to the frosts.
Month-by-month celosia calendar
| Month | Task |
|---|---|
| January | Order seed |
| February | Get propagator, modules and compost ready |
| March | First sowings at 21-25C in modules |
| April | Last sowings. Pot on into 9cm pots. Buy plugs |
| May | Grow on warm and bright. Start hardening off late in the month |
| June | Plant out into warm soil. Pinch plumed and wheat types |
| July | First flowers. Net tall rows. Feed pots |
| August | Peak flowering. Cut often |
| September | Cut stems for drying and hang them up |
| October | Last flowers until frost. Save seed from non-F1 types |
| November | Compost frosted plants. Clean pots and trays |
| December | Plan next year’s varieties |
Common celosia problems
Most celosia problems happen before midsummer, and nearly all come from cold or damp.
- Seedlings collapsing: damping off in warm, humid propagators. Sow thinly in fresh compost, water from below and open the lid daily once seedlings are up.
- Stunted plants with tiny flowers: a cold check or pot-bound roots. Keep young plants above 15C and pot on promptly.
- Wilting in wet compost: cold, soggy compost rots the roots. Stop watering, move the plant somewhere warmer and let it dry a little.
- Aphids under glass: check tips twice a week from April and squash small colonies. Outdoors, ladybirds and hoverflies help. For a bad attack, use an approved product for that use, following the label.
- Red spider mite indoors: fine speckled leaves and webbing in dry rooms. Raise humidity with a tray of damp gravel, and compost badly affected plants.
Common mistakes with celosia
- Sowing on a cold windowsill. It needs 21-25C to germinate well.
- Pricking out from a tray. Sow in modules so the roots are never disturbed.
- Planting out in May. Wait for June and warm soil.
- Overwatering in cool weather. Err on the dry side below 15C.
- Leaving leaves on cut stems. They wilt first and spoil the vase.
Frequently asked questions
Is celosia a perennial in the UK?
No, it’s grown as an annual in the UK. It’s tender and dies at the first frost. Sow fresh seed each spring, enjoy the plants from July to autumn, then compost them.
When should I sow celosia seed?
Sow from March to mid-April under glass at 21-25C. A heated propagator gives the steady warmth the seed needs. April sowings catch up fast in the longer days, so don’t worry if you miss March.
Why is my celosia flowering while it is still tiny?
A cold check has made it flower too early. A chill below about 10C, or roots left to fill the pot, makes young plants stall and throw a small head. Keep young plants above 15C and pot them on promptly.
Can you grow celosia outside in the UK?
Yes, once all risk of frost has passed. Plant out in early June into warm soil, in the sunniest, most sheltered spot you have. It flowers outdoors from July until the first frost. A greenhouse or polytunnel gives taller stems and bigger heads.
How long does celosia last in a vase?
Celosia lasts well in a vase, often longer than most summer annuals. Strip all the leaves, as they wilt before the flower head fades. Cut in the cool of the morning and change the water every couple of days.
How do you dry celosia flowers?
Hang small bunches upside down somewhere warm, dry and airy. Keep them out of direct sun and strip the leaves first. The heads dry in a few weeks and keep their colour well.
Once your celosia is cropping, plan the rest of your cutting patch with the guide to growing cut flowers, or browse more ideas in flowers and plants.
Our team produces practical UK gardening guidance from source research, contributor records and established horticultural practice. Editorial standards are overseen by Matt W.
