Siberian Flag Iris Iris sibirica is an attractive, free flowering Iris with long lasting deep blue flowers. Despite been commonly known as the Siberian Flag Iris, it is a native of Europe, not Siberia. Equally at home in moist or dry soils. As with all Iris the tubers are harmful if eaten. Position: Full sun to part shadePlanting depth: Dry to damp soil to 15cm (6’’) below water levelGrowth rate: SlowFlowering Period: June & JulyHardiness: HardySize: Height: 90cm (36"). Spread: 30cm (12") Aquatic pot and compost variations Aquatic plants come in a variety of pot and compost variations that have different benefits for planting and growing. Mesh Pot (Aquatic Compost)Pot can be removed and plant can be planted directly into soil or margins above or below the water line. Pot and plant can also be placed directly into water to be container grown, but will still need repotting in time. Pot (Aquatic Compost)Pot must be removed and plant should be planted directly into soil or margins above or below the water line. Pot (Regular Compost)Pot must be removed and plant should be planted directly into soil or margins above the water line. Cannot be planted directly into soil below the water line.