Yellow water flag iris ( iris pseudacorus L. )

These grow in water, along the edges of ponds, in bogs, I have them in my swale garden.

They can be invasive use appropriate cautions. Do not plant them unless you are sure you want them. They are extremely difficult to remove once established.

They are used in sewage treatment to remove metals from waste waters.

They grow in full sun and part shade with no trouble here. If it is wet, they will grow.

They bloom prolifically early-mid March and are just now winding down the middle of April.

The Houston summers do not bother them, the cold winter of 2009/2010 caused a little bit of die back, but most of them pulled through just fine.

Yellow flag iris can be found wild in bogs from Scandinavia to Siberia and as far south as North Africa. Clovis I, King of the Franks made it his family flower.  On a campaign from Germany they found their way through the swamp by following the flag irises.  Since they will not grow in deep water, he knew the swamps would be shallow enough to march his army through where ever they found this flower.

These are doing just fine despite more than 3 months of no rain and 100’F plus temperatures.

More information
Iris pseudacorus

4 thoughts on “Yellow water flag iris ( iris pseudacorus L. )

  1. Anonymous said…

    Yes – they DO love to spread….but HELP — they’ve taken over my entire pond 2 years in a row! When I moved in this rental house, the pond was sad and they were too…after fixing it up and adding fish, the 2 plants — iris and water lilies — thrive. However, the iris was never in pots. It is an island of explosion! I want to take out most of them and put them in a few pots, but each time I try to do one for ‘practice,’ the result is a very bleak looking transplant. Any ideas would REALLY be appreciated!
    September 1, 2007 12:58 PM

  2. I had to re-post your comment. You posted it on the blogger account the same day I moved the blog and I didn’t want to lose it.

    I haven’t tried transplanting any of these irises yet. When I transplanted other pond plants it wasn’t easy. Not only do you have to get them in a pot of dirt but you have to convince the dirt to stay in the pot.

    I used clay pots, filled them halfway with dirt, put the bulb in and filled the rest with gravel. I also then cut the leaves back to below the water level and just above the gravel.

    All transplants look sad for a while. This way you don’t have to see them till they get happy and start growing again. They go dormant when it gets chilly which is the best time to take them out and pot them.

  3. I have planted several in my garden about a year and a half ago, but I never have any flowers. The foliage is green and abundant; any suggestions as to what could be missing?

  4. They typically grow in shallow ponds, so they need lots of water and full sun. Mine are not in water, but that spot is boggy.

    If that’s not it, try a fertilizer high in phosphorus, you usually only need use it once. Sometimes that gets plants blooming.

    Mine just started blooming this week. it may be yours will bloom later, often the first couple of years I have a plant it blooms off season.

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