One of the highlights of Morton Hall in May and June is the display of Iris germanica, Iris sibirica and Iris ensata in various parts of the garden. In total, there are about 40 different Iris varieties, flowering in succession from the beginning of May right through to the end of June.
The more vigorous Germanica irises need splitting after flowering every three to five years to ensure a reliable display. Occasionally, they are sprinkled with lime of magnesium in spring which is thought to be beneficial. Sibirica and Ensata irises are divided in the autumn as necessary and fed in the spring with a seaweed extract.