Iris versicolor, known as blue flag iris, is a North American iris with narrow, upright leaves and branched stems of violet-blue flowers. Each flower is 6–8 cm across with white veining and a yellow patch at the base.

Blue flag iris at a glance

Botanical name Iris versicolor
Common name Blue flag iris
Plant type Clump-forming iris; dies back in winter
Height and spread About 60–80 cm tall, up to 50 cm wide
Flowers Violet-blue, 6–8 cm across, veined white with yellow at the base, June to August
Position Full sun or part shade
Soil Moist to wet, acid to neutral soil
Pond depth 0–10 cm of water over the crown
Hardiness RHS H7 – very hardy (below -20°C)
Native to Eastern North America (not UK native)

Where to plant blue flag iris

  • A pond shelf with up to 10 cm of water over the crown
  • Bog gardens and wet borders that never dry out
  • Garden ponds, as a smaller alternative to yellow flag

How to plant and care for it

Plant from spring to summer and do not let it dry out. Divide crowded clumps from midsummer to early autumn.

Is blue flag iris invasive?

It is not native and has escaped into the wild in parts of Britain, so keep it in garden ponds and do not plant it into natural waters.

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 cost less per plant. The 2x Pot & Compost option is two plants supplied with pots and compost.

Pond depth: 0 - 10cm

Light: Full sun or part shade

Hardiness: Hardy

Height and spread: 40 - 80cm tall, 30 - 50cm 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.

Processing Time:
Orders are processed within 1 - 3 business day after payment confirmation. Orders placed on weekends or public holidays will be processed the next business day.

Shipping Methods:

  • Standard Shipping (1-3 days)
  • Express Shipping (1-2 days)

Should you have any questions or concerns about your shipment, feel free to contact us.