The yellow flag iris bears between four and twelve bright yellow flowers on each of its branching flower stalks. This iris thrives in wet areas and when no flowers appear, this iris is present as a tall clump of grayish green blade-shaped leaves.
The yellow flag iris can be propagated by root division in the late summer, after it has finished flowering. This iris can self propagate easily and is considered invasive in many wetlands around the country.
Iris pseudacorus, or yellow flag iris as it is commonly known, caught my attention because of its ability to survive and actually thrive in standing water. When I installed a fountain in my garden I selected this iris as an accent. I love how the strong vertical lines of the 4 foot tall foliage contrast with the flat surface of the water. My 4 Golden Orff fish spend their days in the roots of the iris and only venture into the open areas of water at dusk and through the night. If you have ever grown the yellow flag, you know that it is a vigorous grower to say the least. I have to divide the plants growing in a 3 gallon plastic bucket in my pool every other year.