Plant iris flowers in mid-spring to late summer. Siberian iris prefers a planting site that is full sun, however, the plant can easily survive to part shade. Once you have found your planting spot, work in a 2-inch layer of organic compost.
2. Dig a shallow hole. Plant iris, covering rhizome with soil.
3. Water well the first year. After that Siberian iris is virtually indestructible, particularly if you mulch well, I only water mine during drought.
4. Fertilizer is not necessary in my experience if you regularly amend the soil with compost, organic fertilizer works fine if you feel fertilizing is necessary.
5. Leave seed heads on the plant once flowered to collect seed, or trim off if you like a neater look in the garden.