How to grow Japanese anemones

What are Japanese anemones?

Anemone x hybrida and A. hupehensis are generally known as Japanese anemones, as they both look similar, although other names include Japanese windflower and Chinese anemone. Many cultivars are available, in shades of pink (from rich magenta to soft blush) and pure white. The saucer-shaped flowers may have a single layer of petals, or multiple layers (semi-double or double), and are about 8cm (3in) across, with a circle of bright yellow stamens in the centre.

These vigorous, easy-to-grow perennials have long been popular as border plants, adding valuable colour in late summer and autumn, right through to the first severe frosts. They are herbaceous (so die back in winter and re-sprout in late spring), and belong to the buttercup family.

Japanese anemones have a rather complicated history. They originated in China, from Anemone hupehensis, a native

A native plant is one that originated or arrived naturally in a particular place without human involvement. In the British Isles, native plants are those that were here during the last ice age or have arrived unaided since.

of Hupeh Province. Having been taken into cultivation, they seem to have escaped into the wild in both China and Japan, before being introduced into Europe in the 1800s. The hybrids now available are derived not only from these plants but also white-flowered A. vitifolia, from the mountains of northern India and western China, and violet-pink A. tomentosa, from north-west China.

Choosing the right anemones for you

Most Japanese anemones are easy to grow and low maintenance, suitable for many sites, including shade. They prefer rich, fertile soil that doesn’t get really dry or become waterlogged

Describes soil or potting compost that is saturated with water. The water displaces air from the spaces between soil particles and plant roots can literally drown, unless they are adapted to growing in waterlogged conditions. Waterlogging is common on poorly drained soil or when heavy soil is compacted.

.

Once established, they can form large spreading clumps, so need plenty of space. The flower stems generally reach about 1m (3⅓ft) tall, but in fertile soils can get to 1.5m (5ft), so they are ideal for the middle or back of borders. There are a few smaller cultivars, such as ‘Pretty Lady Diana’, at only 60cm (2ft) tall, which suit smaller spaces and containers.

The flowers attract pollinating insects, so are ideal for wildlife-friendly gardens. Japanese anemones are also resistant to slugs, snails and rabbits, so are a useful choice if these thrive in your garden.

As they flower late in the season, Japanese anemones give a useful boost to borders that may be starting to flag. They combine well many other plants, including ornamental grasses and ferns. Although limited to shades of pink and white, these anemones are elegant and striking in full bloom. White-flowered cultivars in particular, such as ‘Honorine Jobert’, are useful for brightening a shady spot, and work well with most border colour schemes.

To browse photos and descriptions of Japanese anemones, go to RHS Find a Plant. You can also search by height, flower colour, growing position, RHS Award of Garden Merit, Plants for Pollinators, and more, to help narrow down your choices. Seven cultivars have an RHS Award of Garden Merit, which shows they performed well in RHS trials, so are reliable choices.

Microclimates: assessing your garden

How and what to buy

Japanese anemones are widely available as young plants in spring, in 9cm (3½in) pots, or as more mature flowering plants in summer and autumn in 2–3 litre pots. They are sold by most garden centres, with a wider range from perennial

Perennials are plants that live for multiple years. They come in all shapes and sizes and fill our gardens with colourful flowers and ornamental foliage. Many are hardy and can survive outdoors all year round, while less hardy types need protection over winter. The term herbaceous perennial is used to describe long-lived plants without a permanent woody structure (they die back to ground level each autumn), distinguishing them from trees, shrubs and sub-shrubs.

suppliers online.

They are also sold as plug plants

Seedlings or young plants grown singly in small modules, with the advantage that they can be transplanted with minimal root disturbance. Bedding plants and young veg plants are often sold as plug plants of various sizes, with smaller ones requiring more aftercare. They usually need to be potted up and grown on indoors until large enough to plant outside.

and bare-root

These have been lifted from the ground while dormant, with little or no soil around their roots. Various plants may be available bare root, including fruit trees, hedging plants and some perennials. They are generally cheaper than plants in containers, but are only available in winter/early spring, while dormant

plants from some mail-order suppliers in spring – these are usually cheaper and smaller than potted plants, but need to be looked after indoors until they are larger and more robust. See our guide to buying by mail order for care tips.

RHS guide to choosing healthy plants

When to plant Japanese anemones

Japanese anemones are best planted in spring or autumn, when the ground is moist and warm, so they settle in well.

Still, they can be planted at other times too, and are frequently bought in full flower, for instant colour. But bear in mind that they may be slower to get established, so will need additional watering. Avoid planting in extreme weather, especially in hot, dry conditions.

Where to plant Japanese anemones

These are vigorous plants, so they like rich, fertile soil.

Partial shade suits them best, but they will also grow in sun, as long as they don’t dry out. They like plenty of rain, but not waterlogging.

Be aware that they do have a tendency to spread, so don’t plant them in areas where this might cause problems.

How to plant anemones

• Japanese anemones bought in pots are easy to plant, in a similar way to most perennials – see our guide below
• When bought as plug plants
  

  Seedlings or young plants grown singly in small modules, with the advantage that they can be transplanted with minimal root disturbance. Bedding plants and young veg plants are often sold as plug plants of various sizes, with smaller ones requiring more aftercare. They usually need to be potted up and grown on indoors until large enough to plant outside.

  or bare-root
  

  These have been lifted from the ground while dormant, with little or no soil around their roots. Various plants may be available bare root, including fruit trees, hedging plants and some perennials. They are generally cheaper than plants in containers, but are only available in winter/early spring, while dormant

  plants, they first need to be potted up and looked after until they are large enough to plant into borders. See our guide to buying by mail order for care tips

Perennials: planting

Watering

• When newly planted, Japanese anemones need watering, for at least the first summer until established
• Once established, plants in borders should only need watering in long dry spells or if growing in a dry site
• Compact cultivars growing in containers need additional watering throughout the growing season
  

  The period of time when an individual plant is in active growth. This will depend on the local climate and light levels, and can vary between different plants, although it is broadly from spring to autumn.

  , as the limited amount of compost
  

  Can refer to either home-made garden compost or seed/potting compost:

  
  • Garden compost is a soil improver made from decomposed plant waste, usually in a compost bin or heap. It is added to soil to improve its fertility, structure and water-holding capacity. Seed or potting composts are used for growing seedlings or plants in containers - a wide range of commercially produced peat-free composts are available, made from a mix of various ingredients, such as loam, composted bark, coir and sand, although you can mix your own.

  dries out quickly, especially in hot weather

Collecting, storing and reusing water

Mulching

Japanese anemones appreciate a mulch of organic matter (such as garden compost) over the surrounding soil each spring. This adds nutrients

To grow well, plants need a wide range of nutrients in various amounts, depending on the individual plant and its stage of growth. The three key nutrients usually taken up from the soil are nitrogen, phosphorus and potassium. Plants also need carbon, oxygen and hydrogen to make carbohydrates — their main energy source. Carbon and oxygen come from the air as carbon dioxide, while hydrogen is drawn from water absorbed by the roots. Other important soil nutrients include magnesium, calcium and sulphur. Most garden soils contain enough of these nutrients to support healthy plant growth.

, helps to deter weed germination

Germination is the process by which a seed develops into a new plant. It starts with the seed coat absorbing water, expanding and splitting, which allows oxygen and water into the seed so its food reserves can be broken down and used by the embryo for growth. The first root (called the radicle) pushes into the soil to anchor the new plant in place and start absorbing water and nutrients. The first shoot (called the plumule) then grows upwards, out of the soil, towards the light.

and holds moisture in the soil through summer.

Feeding

Anemones don’t generally need feeding when growing in rich soil. Regular mulching is usually sufficient.

Caring for older plants

Japanese anemones naturally spread, eventually forming clumps more than 1.2m (4ft) wide. If they get too large, you can reduce the size of the clump by digging out sections in late autumn or early spring and replanting elsewhere. Thriving clumps can be divided every three or four years – see Propagating, below.

Simply snip out dead foliage and old flower stems in early spring, right at the base. Do this before new growth starts, so you don’t accidentally damage any emerging new shoots.

If possible, resist the temptation to tidy up faded growth in autumn, after flowering, as it provides valuable shelter for insects and other small creatures over winter.

Even though the flower stems grow quite tall, they are sturdy and don’t generally need staking.

Perennials: cutting back

Deadheading plants

Dividing clumps

This is the easiest way to propagate well-established Japanese anemones and is best done in spring. The resulting plants will be exactly the same as the parent plant.

However, plants can be slow to recover and may take a year to start flowering again.

Perennials: dividing

Taking root cuttings

Japanese anemones grow readily from root cuttings

A method of growing new plants from parts of an existing plant, such as sections of root, stem, leaf or bud. When prepared correctly and planted in the right conditions, they can produce roots and eventually become independent plants. There is a wide range of different methods for taking cuttings, depending on the plant and time of year.

taken in autumn. It’s best not to dig up the clump though, as this can cause a check in growth. Instead, simply dig down beside it to find a fleshy root, and snip it off.

Short lengths of root should be laid horizontally onto trays of damp, free-draining, peat-free potting compost

Can refer to either home-made garden compost or seed/potting compost:

• Garden compost is a soil improver made from decomposed plant waste, usually in a compost bin or heap. It is added to soil to improve its fertility, structure and water-holding capacity. Seed or potting composts are used for growing seedlings or plants in containers - a wide range of commercially produced peat-free composts are available, made from a mix of various ingredients, such as loam, composted bark, coir and sand, although you can mix your own.

, to form roots and shoots.

The resulting plants should establish well and flower in a couple of years. They will be exactly the same as the parent.

Cuttings: root

From seed

• Freshly gathered seeds of species anemones, such as A. hupehensis, should germinate well if sown in moist, gritty, free-draining, peat-free seed compost
  

  Seed compost is a free-draining compost formulated for germinating seed. It often contains a mix of fine materials including sterilised loam, coir, coarse sand or grit. It contains low levels of nutrients, as high levels could damage seedlings.

  . The resulting plants will be identical to their parent
• Hybrids, such as A. x hybrida, tend to produce very little fertile pollen, and seed is rarely produced
• With packeted seeds, the choice of cultivars is very limited
• Seed-raised plants will take several years to reach flowering size

Seed: collecting and storing

RHS guide to sowing seeds indoors

Pests and diseases

Japanese anemones are usually healthy, trouble-free plants when given the right growing conditions. They are even resistant to slugs, snails and rabbits.

However, they may occasionally be affected by:

• Powdery mildew – especially in dry conditions
• Leaf and bud eelworms – these cause small angular patches of damage on older leaves, which should be picked off and destroyed
• Yellowing or browning leaves – may be a sign of dry soil. Apply a mulch to help hold moisture in the soil

When buying plants, avoid any with distorted or discoloured leaves (they should be dark green), as this may be the sign of a viral infection.

Managing pests and diseases without chemicals

Preventing pest and disease problems

Controlling Japanese anemones

A slight word of caution about these vigorous plants – once established, they do tend to spread and can be difficult to contain, so are not ideal if space is limited.

They can also be tricky to remove, as they will re-grow from any roots left in the ground. Persistence may be required.

Potentially invasive plants

Get more gardening advice

If you’re a member of the RHS, you can use our online Gardening Advice Service, via MyRHS, for any gardening problems or queries.