Sunday, April 20, 2014

Bearded Irises. Bacterial Rot. New Order. 4.20.14

Iris Bed.  Bacterial Blight Takes a Toll.

The Last Shipment of Historic Iris Rhizomes.
That Package held a lot of rhizomes.
Disappointed.  All 3 beds of bearded iris are affected by bacterial blight.  Every plant.  A few have died, completely.  This follows another week of rain.  The photo doesn't look as bad as they do in reality.

The irises in the front border were not affected.  That must indicate, the TLC these got was detrimental.  I can't think of any other reason

Since every iris was affected, it's no use removing them and trying to isolate the diseased ones.  I'll continue weeding and pulling out dead fans.  Im guessing about 1/4 of the fans have rotted.  Maybe more.  Most of the leaves are at least a little affected.

Interesting timing for the order to arrive from Old House Gardens.  But they did.  I did not want to plant them on top of rotting iris rhizomes, so gave them a temporary place in what I planned to have as a vegetable bed.  After things dry out, if it looks like the disease rhizomes survive and come out of it, I'll plant them together again.

This is the first time this has happened..  It must be the combination of feeding them too well, plus the rainy chilly weather after a burst of growth.


  1. Store-bought potting mixes contain peat moss which holds too much water. If you can get actual soil without peat moss for your bed it would be great. I think a local nursery can sell you topsoil by the yard.

  2. Thanks for the comment. There is no store-bought potting mix and no peat moss in the raised beds. They contain native soil mixed with compost.

    It's a heavy clay soil, so probably needs something for extra drainage. If I start new iris beds, I may want to add gypsum.

    I realize adding the compost may have the same effect as peat moss. I will let the compost deplete itself this year.