Sensation Mixed
Tall, open plants with large single flowers in mixed colours. A very common bedding and cutting strain in UK catalogues.
Cosmos in Frilford
Cosmos bipinnatus
A half-hardy annual grown for long-lasting, daisy-like flowers. In the UK it does best in a sunny, sheltered spot with free-draining soil, and it flowers freely from summer into autumn if you keep it deadheaded.
90 cm · Full Sun · Moderate Water
Calibrated to Frilford · last frost ≈ 5 May
| Activity | January | February | March | April | May | June | July | August | September | October | November | December |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sow indoors | No | No | Yes | Yes | No | No | No | No | No | No | No | No |
| Plant out | No | No | No | No | Yes | Yes | No | No | No | No | No | No |
Growing guide
Step-by-step instructions for growing Cosmos
01
Sow Seeds Indoors
21 Mar to 14 AprSow seeds in trays or modules from 21st March to 14th April, using of fine compost. Keep them at and just moist, not wet.
02
Prick Out Seedlings
16 Apr to 30 AprMove seedlings on when they are large enough to handle, from 16th April to 30th April. Pot them into small pots and keep them growing in a bright, frost-free place.
03
Harden Off Plants
21 Apr to 5 MayAcclimatise plants over 15 days before planting out, from 21st April to 5th May. Put them outside in the daytime at first, then leave them out for longer each day so they do not check in cold weather.
04
Plant Out
19 May to 5 JunPlant into free-draining soil from 19th May to 5th June, spacing plants apart. Water in thoroughly straight after planting and protect young plants from slugs and late cold snaps if needed.
05
Deadhead & Maintenance
26 Jun to 19 OctRemove fading flowers regularly from 26th June to 19th October. This stops the plant setting seed too early and keeps it producing flowers until the autumn frosts. Tie in taller stems if the plants get blown about, and water during dry spells.
Companion plants
Tap a plant to see why it works (or doesn't) with Cosmos.
Good companions
Plants to avoid
Why companion planting matters
Companion planting can deter pests, improve pollination, and make better use of space. Some plants confuse pests or attract beneficial insects; others improve soil or offer shade to neighbours that need it.
Suggested varieties
Popular varieties of Cosmos to consider
Purity
Tall white-flowered plants with good stems for cutting. Reliable in a sunny border.
Sea Shells Mixed
Distinctive tubular petals and strong colour range. Good for a lighter, airy planting effect.
Sonata White
A shorter, compact type suited to pots and front-of-border planting. Useful where space is limited.
Related plants
Explore similar plants you might like
Cosmos guides by town
See how Cosmos timing shifts in other towns with different frost dates.