Iris 'Kimboshi', sold as Iris × pseudata 'Kimboshi', is a pseudata iris: a hybrid between the yellow flag (Iris pseudacorus) and the Japanese iris (Iris ensata), bred by Hisaharu Ueki. Its name means 'golden hat'. Early in the iris season it carries pale yellow flowers with a dark yellow signal patch and fine brown lines, above upright, sword-shaped leaves.

'Kimboshi' at a glance

Botanical name Iris 'Kimboshi' (pseudata hybrid, I. pseudacorus × I. ensata)
Common name Pseudata iris
Plant type Upright, clump-forming iris; a sterile hybrid
Height and spread About 50–60 cm tall
Flowers Pale yellow with a dark yellow signal patch and fine brown lines, May and June
Position Full sun
Soil Damp to wet soil, including heavy wet clay
Pond depth 0–10 cm of water over the crown, or wet soil at the pond edge
Hardiness Hardy; not rated by the RHS (USDA zones 5 to 9)
Native to Garden hybrid of yellow flag and Japanese iris (not UK native)

Can it grow in water?

Yes. Plant Delights says it can grow as a marginal aquatic, as well as in damp to wet soil, including heavy wet clay. UK and US aquatic nurseries give up to 10 cm of water over the crown.

Will it spread like yellow flag?

No. It is sterile and sets no seed, so unlike its parent, the yellow flag, it will not seed around. Plant Delights says it is not a weed risk.

Is it poisonous?

Yes. Irises are harmful if eaten by people or pets, so wear gloves when handling it.

Which size should I buy?

Bare-root plants (7 cm, 9 cm, 1 litre and 3 litre) arrive without a pot or compost and are the most economical way to plant a group. Potted plants (9 cm, 1 litre and 3 litre) arrive growing in our peat-free compost and give a faster display. Packs of 3 come in 7 cm, 9 cm, 1 litre and 3 litre bare-root sizes and cost less per plant. The 2x Pot & Compost option is two plants supplied with pots and compost.

Pond depth: 0 - 10cm

Light: Full sun

Hardiness: Hardy

Height and spread: 40 - 80cm tall, 50 - 100cm wide

Planting and flowering months are shown in the calendar under the photos.

Bare root (7 cm, 9 cm, 1 litre, 3 litre): plants sent without a pot or compost, ready to plant straight away. The most economical way to plant a group.

Potted (9 cm, 1 litre, 3 litre): plants growing in our recycled, peat-free compost made in Lincolnshire. Larger sizes give a faster display.

Pack of 3 (7 cm bare-root, 9 cm bare-root, 1 litre bare-root, 3 litre bare-root): three plants of the chosen size at a lower price per plant.

2x Pot & Compost: two plants supplied with pots and compost.

Sizes shown with a line through them are currently unavailable.

At Lincs Plants, we strive to provide fast and reliable shipping to ensure your plants arrive in perfect condition. We offer 1-3 day shipping through a variety of dispatch methods to suit your needs.

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