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Home & garden.

16 August 2021

How to grow Japanese anemones

Japanese anemones are great for brightening up late-summer borders. Discover our best varieties and tips for how to grow them.
CT
Ceri Thomas
Japanese anemones

Keeping your garden blooming into autumn can be a challenge, but with Japanese anemones you can enjoy their indispensable, cottage-garden charms from late summer onwards. Once they get settled they’re easy to grow. Some might say too easy, as they can work their way along your borders with enthusiasm, popping up in unexpected places.

Which? Gardening magazine grew a range of popular varieties in the north and south of the UK over two years to see which would give us the best display and be hardy enough to get through UK winters.


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Key facts

PLANT TYPE Herbaceous perennial

POSITION Sun or shade 

SOIL Moist but well-drained

How to grow Japanese anemones: month by month

January
February
March
April
May
June


DIVIDE
DIVIDE


July
August
September
October
November
December
FLOWERING
FLOWERING
FLOWERING
FLOWERING
CUT BACK/ROOT CUTTINGS

Best Japanese anemone varieties

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Best Buy Japanese anemones
What it looks like
Variety name
Height x spread
75 x 65cm
The deep, rose-pink of the blooms combined with the double layer of petals and dense ring of yellow stamens made a very striking flower. The sheer mass of them was quite a sight, especially in the second year when the plants had grown into big, loosely shaped clumps. Of the plants in our trial, they were one of the longest in flower, and still looked good in mid-October, both in north London and in Scotland. Peak flowering: Aug-Oct
What it looks like
Variety name
Height x spread
80 x 100cm
This was one of the last varieties to start flowering, beginning right at the end of August, and it was still going strong in late October. The strong pink and double layer of petals gave a terrific splash of colour. The plants were pretty well-behaved, too; lacking the height of some of the more willowy varieties, but making up for it with shorter, denser clumps and less tendency to spread. Peak flowering: Aug-Oct
What it looks like
Variety name
Height x spread
45 x 70cm
Breeders have introduced some very compact varieties recently that would fit into the smallest gardens. There were so many flowers on these little round clumps that the leaves, and later the dead heads, all but disappeared in late summer. They were also one of the longest-flowering varieties in the trial. Peak flowering: Aug-Oct
What it looks like
Variety name
Height x spread
45 x 50cm
This recently introduced variety isn’t, strictly speaking, a Japanese anemone, although one of its parents is thought to be and it shares many of their attributes. It started flowering comparatively early and bloomed merrily through the hottest, driest weather that last summer threw at it, while other varieties flagged. Its large, nodding blooms weren’t as numerous as some of the other varieties in the trial, but they were cool and classy, and the whole plant was simply lovely. Peak flowering: Jul-Sep

How we test Japanese anemones

We grew 17 varieties of Japanese anemone and included anemone ‘Wild Swan’, so we could see how it compared. We planted three of each variety at our Capel Manor trial garden in north London and at Logan Botanic Garden near Stranraer in Scotland. We grew the plants for two years and assessed them throughout for: flowering impact and number of flowers, how long they lasted and whether they had scent; how well the plants established and developed within two years and how invasive they were; their attractiveness to pollinating insects; and how susceptible they were to common problems. During the second year of the trial, the weather was very hot and dry, and the plants in the well-drained soil at Capel Manor needed extra watering on several occasions. No extra watering was needed in Scotland.

Caring for your plants

Planting

Try to buy plants when they’re in flower or from a reputable nursery or garden centre to make sure you get the variety you want. Choose your planting area carefully as once established, Japanese anemones can be hard to remove. Plant in a spot with some shade for best results and in soil that stays moist in summer, but is well-drained in winter. Add well-rotted garden compost when planting if your soil is poor

Watering

Keep plants well-watered in their first year, until they’re established, and even then you shouldn’t let the soil dry out too much.

Cutting back

Cut back all finished flower stems to ground level as soon as they fade to prevent them from setting seed. Cut back the whole plant in late autumn-late winter to make space for the new growth in spring.

Propagating

Plants can be divided in spring, or propagated by root cuttings in autumn.

Common growing problems

Spreading too far

Invasive varieties can be hard to keep in check, so promptly weed out any growth that appears where you don’t want it.

Slugs and snails

These can be a problem in spring, but rarely cause much damage once plants are growing strongly. If you want to, use organic slug pellets or biological control.

Read more about slugs and snails

Powdery mildew

This is common in dry soils, so keep them well-watered in dry spells. Mulching around your plants in spring with garden compost or spent mushroom compost will also help.

Read more about powdery mildew