How to plant
When to Plant
Plant iris rhizomes in late summer to early autumn so they can establish roots before winter. For bulb-forming types like Dutch irises, plant in autumn before the first frost.
Where to Plant
Irises prefer a bright, sunny spot that receives at least 6 hours of direct sunlight. They thrive in well-draining soil and dislike sitting in water. Poor drainage increases the risk of rot, especially for rhizome types.
Preparing the Soil
Loosen the soil to a depth of 20–25 cm and remove any rocks, weeds, or debris. Mix in compost or organic matter to improve texture and drainage. In heavy soil, consider adding grit or coarse sand.
Planting the Rhizomes / Bulbs
For rhizomes: Place them horizontally with the top just at or slightly above soil level, and spread roots gently below. Keep spacing around 30 cm between plants.
For bulbs: Plant pointed side up, around 10 cm deep and 10 cm apart. These are often used in dense groupings for a more compact floral display.
After Planting
Water once to settle the soil. Avoid overwatering—irises like moist conditions when growing but resent soggy soil during dormancy.
Spring Growth and Blooming
Iris foliage emerges first, followed by strong flower stalks. Depending on variety, blooming happens from mid to late spring into early summer. Their elegant forms and varied colors make them standout features in any garden.
After Blooming
Cut flower stalks back after blooms fade. Leave the foliage in place until it yellows and dies back naturally—this is essential for feeding the bulb or rhizome for future flowering. If overcrowded, divide and replant rhizomes in late summer.
Extra Growing Tips
Irises perform best when left undisturbed for several years. Avoid mulching directly over rhizomes. In containers, use shallow pots with excellent drainage. Deadhead blooms to encourage further flowering, and watch for pests such as iris borers in humid climates.
