Irises are care-free survivors par excellence that come in a wide variety of colours. These are some expert tips on growing irises, and helping them look their best.
1. Pick a variety
Irises are available in every colour and combination of colours except true red. Be sure to pick a type that will grow in your region.
- The best-known irises are the tall, bearded types. But beardeds now come in several sizes, from miniature dwarfs to large-flowered “tetraploid” varieties.
- Old hybrids tend to be tougher and are often more fragrant. The wonderful bubble gum scent is one you’ll never forget.
- An important innovation is the development of re-blooming irises, which come in different colours and styles.
- Elegant Siberians (Zone 4) have purple, blue, wine, pink or yellow flowers. Although tolerant of shade, Siberians thrive where they have sun, abundant moisture and good drainage.
- There are several durable and adaptable species. These include Louisiana irises (Zone 6), miniature reticulata irises (Zone 5) and water-loving flag iris (Zone 4).
2. Plant them from rhizomes
- Most irises grow from rhizomes that wander horizontally just below the soil’s surface.
- Divide plants a month or so after blooming.
- Unearth the rhizomes and cut off five-centimetre-long to eight-centimetre-long segments with a fan of leaves and some roots attached.
- Dry rhizomes in an airy, shaded place for several days.
3. Watch out for pests and disease
- Bearded irises are prone to two main problems: iris borers and soft rot.
- To control borers, which tunnel in leaves and rhizomes, remove and dispose of infested tissue.
- Soft rot is a bacterial disease that gains entry when rhizomes are damaged by cultivation or borers. They become soft and smelly.
- To combat soft rot, dig up plants, select healthy rhizomes and replant in a different spot.
- Siberian varieties aren’t prone to borers or leaf spots.
Irises are the perfect flower for busy gardeners because of their easygoing nature. They require almost no maintenance outside of pest control. The trick is mostly picking the kind that grows best in your region.