Description
Iris laevigata 'Mottled Blue' is a form of the Japanese water iris, with upright, sword-shaped leaves. In May and June it produces blue flowers with mottled markings.
'Mottled Blue' at a glance
| Botanical name |
Iris laevigata 'Mottled Blue' |
| Common name |
Japanese water iris, smooth iris |
| Plant type |
Clump-forming iris; dies back in winter |
| Height and spread |
About 70 cm tall, up to 50 cm wide |
| Flowers |
Blue with mottled markings, May and June |
| Position |
Full sun |
| Soil |
Moist to wet, humus-rich, acid to neutral soil, or shallow water |
| Pond depth |
0–15 cm of water over the crown |
| Hardiness |
RHS H6 – hardy in a very cold winter (-20 to -15°C) (species rating) |
| Native to |
Garden form of an East Asian iris (not UK native) |
Can it grow in water?
Yes. Iris laevigata is a true water iris that thrives at pond and stream margins, with up to 15 cm of water over the crown.
Where to plant it
- A sunny pond shelf, 0–15 cm deep
- The wet margins of ponds and streams
- Bog gardens with acid to neutral soil
How to plant and care for it
Plant in spring or summer. Watch for slugs, snails and iris sawfly.
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.
