Japanese anemone

Questions about Japanese anemone

Does Japanese anemone need sun or shade?

Japanese anemone grows in part sun (4 to 6 hours of sun, including some afternoon sun) and part shade (2 to 4 hours of sun, mostly in the morning).

It wants soil that stays evenly moist, rich in organic matter, and a good soak in dry spells.

What zones does Japanese anemone grow in?

USDA zones 4 to 8. It is hardy to zone 4, which means it survives winter nights down to about −20 °F (−29 °C).

Above zone 8 it struggles: the zones measure winter cold, but a plant's top zone usually means the summers are too hot or the winters too mild for it to rest.

Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.

When does Japanese anemone flower in my zone?

In zone 5 it flowers mid August to early October. As a summer flower it moves about half a week for every zone: earlier where it is warmer.

Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.

How far apart should Japanese anemone be planted?

24 in (60 cm) apart, from the middle of one plant to the middle of the next. That is about its full width, so each plant keeps its own outline.

It grows 3 ft (90 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.

How many Japanese anemone plants do I need?

At 24 in apart, set out in staggered rows:

• 3 to fill 10 square feet (about 1 m²)
• 6 for a single row 10 ft (3 m) long
• 10 to fill a 4 × 8 ft bed on its own

In a mixed border, plant it as a group of three or five, with a second group further along in the other number.

In the bed above, the planner used three in one group.

Is Japanese anemone poisonous to dogs and cats?

Yes: mild toxicity to people, dogs, cats and horses. The sap can irritate skin, and all parts cause mouth and stomach upset if eaten.

Rated from NC State Extension. Where references disagree, the more cautious rating is used.

Is there a pet-safe plant like Japanese anemone?

These come closest to doing what Japanese anemone does, and no toxicity is recorded for them:

• Turtlehead 'Hot Lips': the same job in a bed, the same flowering time and the same colour; 6 in narrower.
• Blue mistflower: the same job in a bed and the same flowering time; 6 in shorter, blue, not pink.
• Joe-Pye weed 'Baby Joe': the same job in a bed and the same colour; 4 in narrower, flowers late July to mid September.

Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.

Will Japanese anemone spread?

It spreads sideways, by runners or roots; the risk of it taking over is high. Slow to settle in, then spreads widely by underground runners and is hard to remove. Give it room or a root barrier.

What flowers after Japanese anemone?

Japanese anemone is over by early October. These start as it finishes and carry the same spot on, so it never goes flat:

• Japanese onion 'Ozawa': from early October to early November, 10 in tall, to stand in front of it and cover its fading stems.
• Bodnant viburnum 'Dawn': from early November to late December, 10 ft tall.
• Common witch hazel: from mid October to late November, 15 ft tall.

What does Japanese anemone look like in winter?

Japanese anemone dies down to the ground and there is nothing to see until spring. The old stems can be cut in autumn, or left until spring as shelter for overwintering insects.