Dividing clumps promotes flowers as it allows the roots to grow into fresh earth.
After flowering the stems can be dead headed to save the plant wasting energy in producing seeds. In winter the clumps can be tidied by trimming down the old foliage before the re-growth in the spring.
Seed may not come true to type, and it will also be a four or five years before the root is large enough to support flowering. The easiest way to grow more iris is to split a clump in early spring before growth starts.
To split a clump of iris dig it up with the surrounding earth. Spike in two garden forks, back to back, and leaver the clump apart into manageable lumps. Replant at once. If you don’t have two garden forks, it is possible to chop up the clump using a small saw (careful!)
Siberian iris is very hardy, so ensure you wait until all danger of frost has passed in your area before considering planting outside.Iris can be used as cut flowers, but the blooms even if left in the garden only last a few days.
Seed can be saved it it may not grow to type. Pods are ripe in late summer but it can take a few years to grow a plant to flowering size.
These estimates for how long Siberian iris takes to sprout, grow and harvest are from real observations from real gardeners, right around the world.
Average 90 days | Min 90 days | Max 90 days (1)
Average 332 days | Min 325 days | Max 341 days (2)
Average 587 days | Min 587 days | Max 587 days (1)
‘sibiricus’ with links to Siberia
Iris
Misspellings: Iris sebirica, Iris siberica