Cosmos in Becconsall
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.
Growing Guide
Step-by-step instructions for growing Cosmos
Planting Calendar
Sow Seeds Indoors
18 Feb – 14 MarSow seeds in trays or modules from 18th February to 14th March, using of fine compost. Keep them at and just moist, not wet.
Prick Out Seedlings
16 Mar – 30 MarMove seedlings on when they are large enough to handle, from 16th March to 30th March. Pot them into small pots and keep them growing in a bright, frost-free place.
Harden Off Plants
21 Mar – 4 AprAcclimatise plants over 15 days before planting out, from 21st March to 4th April. Put them outside in the daytime at first, then leave them out for longer each day so they do not check in cold weather.
Plant Out
18 Apr – 5 MayPlant into free-draining soil from 18th April to 5th May, spacing plants apart. Water in thoroughly straight after planting and protect young plants from slugs and late cold snaps if needed.
Deadhead & Maintenance
26 May – 14 NovRemove fading flowers regularly from 26th May to 14th November. 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
Sensation Mixed
Tall, open plants with large single flowers in mixed colours. A very common bedding and cutting strain in UK catalogues.
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
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Brussels Sprouts
Brussels sprouts are a hardy winter brassica (cabbage family) that form sturdy, leafy stems often around 60–90cm tall. They produce edible mini-cabbage buds along the stem from autumn through winter. Thanks to their cold tolerance, sprouts remain productive into late winter, and frost actually improves their sweetness.
Calabrese
Calabrese (broccoli) produces a large central head of tightly-packed green buds, followed by smaller side-shoots after the main head is cut. It’s a cool-season brassica crop. Grow it in full sun with fertile, well-drained soil and keep plants watered during dry spells. Harvest the heads while firm, then leave the stem in the ground to allow side-shoots to develop.