Hello,

My question is regarding Siberian Irises - I understand that the rhizomes are planted in the spring, but most other irises are planted in the fall. Do you know why this is? What is different about Siberian irises that means they should be planted in the spring - is it moisture or sensitivity to cold, or something else?

Many thanks

Stephanie

I think you can plant them anytime between spring and fall. I planted mine in the middle of summer - they are fine.

Yes, you can pretty much plant siberian iris anytime, and yes they are different. Iris is a very large plant group, and some are planted only in the fall, the bearded iris that come to most people's minds as iris is best planted in in late summer, woodland types usually prefer early summer.

I've moved them various times..the roots are more like a fibrous mass and won't pull apart like bearded iris do.

to the Iris Forum!

Sibs can be planted all year round, unless the ground is frozen. They need more water than the bearded irises, especially when newly planted, so keep that in mind and they will be just fine. Enjoy!

It seems to me that Siberian irises have roots that grow from spring to autumn. But it is hot in summer, so they are transplanted in spring or autumn. I like autumn planting better.

Hello all, thank you for your replies!

I guess my question is also why is there a difference between Siberian and bearded? Does planting in the spring suit Siberian irises needing more water? Or is it to do with being more sensitive to the cold, or something else?

Thank you!

Sibs are definitely not more cold sensitive. Most varieties thrive in colder areas that get snow.

There are many differences in the morphology of beardless iris vs bearded. While under the same banner "iris" each species has different growing needs, different forms, and different zonal constraints.

I guess it would make sense to plant them in the spring if you are in an area with a shorter growing period and want them to be well established before it gets cold again. I am in an area with milder winters but hot humid summers. I plant them in the fall so they aren't stressed by the heat while first getting their roots established.

Bearded irises can pretty much be transplanted any time the soil is not frozen. The reason most people plant them in late summer is so that they don't disrupt the bloom time in the early summer. Where I live, you take a chance of having them heave out of the ground if planted too late in the fall, as the freeze thaw process will push them out of the ground if they haven't had enough time to establish a good root system. You can still plant them, but you'd be best to put a brick or somethng heavy on the rhizome to keep it in the ground. Most vendors of Siberian irises send them in the fall for planting. I have transplanted some in the summer when I just dig them from one spot and move them to another and it seemed to be OK in my climate. Leslie made it clear that there is often no one right answer to that question, and conditions in ones area may require different solutions.