Hi Caroline, The rhizomes can be planted flat, making sure the roots are covered in soil. Point the bigger end in the general direction towards which you’d like the plants to spread in the garden.

Yep. But refrain from removing more than about a third of the total root surface.

I would add a bit of compost or garden soil to add some nutrients before planting.

I just obtained rhizomes from someone’s existing plants. When I plant in my ground do they need compost and/or mulch since they’re already established?

Thanks!

Hi Linda, How lucky they bloom twice a year! I read a blog post by a gardener in zone 9b that says August is the time. I would also consider consulting the American Iris Society for advice tailored to your growing zone.

When do you divide an Iris when it blooms twice a year. Spring-summer and then again in December – January. I live in zone 9.

Hello, There are a few things that could affect bloom production, including if the rhizomes are becoming overcrowded and need dividing.