wetland wildflower
Slender Blue Flag
Iris prismatica
Also known as Slender Blue Iris, Coastal Iris
1 of 3Native to the Northeast and the Southeast and southern Canada
Coastal areas from Nova Scotia to Georgia; also southern Appalacians
- Light Partial shade Sun tolerance
- Moisture Moist Moisture preference
- Zones 5–8 Cold to heat range
- Bloom May–Jun Flowering time
- Height up to 32 in to 81 cm
- Life cycle Perennial Annual to perennial
In the garden
A wetland wildflower for partial shade and evenly moist soil. Its blue flowers peak in June. At up to 32 in, it suits rain gardens, pond edges, and damp low spots. Hardy in USDA zones 5–8.
Growing conditions
Light
Full sun Partial shade Full shade
Moisture
Dry Moist Wet
Hardiness zones
Find your zone:
When it blooms
The Slender Blue Flag's blue flowers bloom May to June, peaking in June. This early-summer display draws butterflies and moths.
Slender Blue Flag blooms blueFoliage
Pollinators & wildlife
- Butterflies Peck's Skipper also Long Dash
- Moths Nessus Sphinx
- Beetles Spotted Cucumber Beetle
Full plant details
Where it grows
- Habitat
- WetlandThe wild plant community it grows in.
- Native range
- The Northeast and the Southeast and southern CanadaUnited States (15): CT, DE, GA, MA, MD, ME, NC, NH, NJ, NY, PA, RI, SC, TN, VA. Canada (1): NS. Where it grows wild on its own, by state and province.
- Native distribution
- Coastal areas from Nova Scotia to Georgia; also southern AppalaciansThe same native range, usually more exact than the state list, and often noting where it has spread beyond it.
Growing conditions
- Light
- Partial shadeHow much sun it takes, from full sun to full shade.
- Moisture
- MoistThe soil dampness it prefers, from dry to wet.
- Hardiness zones
- USDA 5–8 · Canadian 5–6The cold-to-heat climate range it survives.
- Soil
- Moist, acid soilThe soils it grows in naturally.
Growth & form
- Height
- up to 32 in (to 81 cm)Typical mature height.
- Life cycle
- PerennialWhether it lives a single season (annual), two (biennial), or returns for years (perennial).
Flowers, foliage & fruit
- Type
- WildflowerWhat kind of plant it is.
- Bloom
- May–JunWhen it flowers.
- Flower color
- BlueThe bloom color, or colors.
- Fruit/Seeds
- CapsuleThe seed or fruit it sets after flowering.
- Toxicity
- Poisonous if eatenWhether any part is poisonous to people or pets.