Louisiana irises need fertile well-composted acid soil (pH 6,5 or lower). POSITION: The perfect place is under deciduous trees that allow sun through in winter but provide dappled shade in summer.
PLANTING AND PROPAGATION: From February to April.
FLOWERING SEASON: In spring from September to October.
SIZE: From about 80cm up to 1,2m high. FERTILISE: Feed regularly from February to July with a high-nitrogen fertiliser (2:3:2 or 3:3:3), and from August onwards, with a high-potassium fertiliser (5:1:5) to encourage flowering in spring.
WATER: Water regularly. During dry winter months, give iris beds a thorough soaking at least once a week.
CARE: After flowering in spring, they become dormant, but should still be watered well and mulched heavily with compost to retain moisture and fertility. FROST TOLERANCE: Hardy.
THIS SPREAD, CLOCKWISE FROM FAR LEFT: Louisiana irises thrive in all kinds of soil. ‘Bubblegum Ballerina’. ‘Peaches and Wine’. ‘Jacaranda Lad’. ‘Heather Pryor’.