A Gardeners Forum Forums General Discussion The Banter Hall Gardener's Chat September dividing

I want to give my daughter a bunch of plants for her new home and we are waiting till September to do that. I am going to divide a bunch of things and wonder if most perennials will be successful. In particular I am wondering about a Siberian Iris. It only had one bloom on it this year and I am not sure what to do with it. It has gotten quite large and am thinking I need to divide into 4-5 plants. Anyone have experience to share?

If your iris is a huge clump with just one bloom, it's definitely a sign it's time to divide. To divide, dig up the clump, wash off the soil, and check for disease or pests (soft rhizomes or holes - may the iris borer). Cut those pieces off. Then, divide into suitable pieces and replant (within a week if kept moist). The last thing you want to do is leave it with its roots exposed in full sun. After dividing, you can (but not absolutely necessary) sprinkle on some fungicide/horticultural sulfur. When replanting, make sure the top of the rhizome is visible, and the root are 'draped' over a small mount of soil in the ground. My own trick: after the first hard frost/snow, put a brick over the rhizome and remove it when you see new growth in the spring. The freezing/thawing of spring can lift newly planted iris out of the ground, and this will keep it in. You HAVE to remove the brick later because iris like to have their 'feet baked in the sun.' If you use a knife to cut it up into pieces, make sure your knife is sterilized before cutting, and after cutting to prevent spreading disease. Sterilizing in between cuts is recommended by some 'experts' but i've never done that and i've been fine in terms of not getting diseases. Sterilizing between DIFFERENT plants, I would STRONGLY recommend.

I am soooooooo pleased you responded. Very helpful info. Thanks.

Good info Kenny. Thank you for taking the time to write it out for us.