A very showy native iris of central and eastern Canadian wetlands. Its complex and quite beautiful violet-purple 10 cm (4″) wide flowers bloom from June to July on stocks held above the sword-like foliage. Northern Blue Flag prefers wet to moist soil (although they will grow in standing water up to 10 cm (4″) deep) in full sun locations. Plants grow to 60-90 cm (2-3′) in height with the tough creeping rhizomes creating slowly expanding clumps. It is found in the margins of swamps, marshes, ponds, streams and very wet meadows. Perennial hardy to Zone 3. Please note that the roots are very poisonous. Packet $1.99. 2 g $7.50. 5 g $11.50.
How to Grow
60 seeds/gram. Seed can be started indoors in a soil-less mix in February. After sowing, moisten the growing medium and place the container in a refrigerator or freezer for 3-4 months before bringing it back into the warmth (check the container periodically during this long stratification period to make sure the growing medium does not dry out or that seed does not start to sprout. If some seed does sprout, plant them in another container as soon as possible and move them under the grow lights in the warmth). For seed that hasn’t sprouted after the stratification period is complete, move the container to the warmth and keep at 20 C (70 F) for the 20 to 40 day germination period. Note that germination can be even longer and is often sporadic. After germination, grow seedlings on under lights at a slightly cooler temperature then harden off and transplant outside to a sunny site with moist to wet soil. Due to seed dormancy and irregular germination, direct sowing in late fall is highly recommended as this allows dormant seed to be naturally stratified over the winter.