Acorus, middle of picture, installed in Ocean Springs MS
Variegated Acorus is a sweet flag, invasive as hyacinths. It grows naturally along banks of any water, maybe a mud puddle if the puddle is there long enough. I keep it potted up in the pond to keep it under control. When starts jumping out of its pot, just whack off all the stems coming from every hole in the pot. If you don't watch out, it will break the pot in its haste to get free.
It gets 12 - 18" tall in the pot and then starts getting wider. I usually divide it yearly. After a few years, people will start avoiding you if they see you coming with more acorus to share with them. But it is pretty, not grown for its flowers, but for the foliage.
It can handle partial shade and is hardy, surviving in zone 5 down to zero degrees or colder. I am sure it doesn't grow as fast and furious in the cooler weather like it does in zone 9a where I am.
Acorus gets scale...all the time. Here's what I do. I cut the acorus back to about 1" tall and suberged the pot, plant and all. When it comes back up out of the water, the scale is gone, drowned.
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