How to Grow Dwarf Iris
Iris reticulata
Iris reticulata is a tiny bulbous iris flowering in February-March, among the first blooms of spring. Plant bulbs 8-10cm deep in autumn in full sun with sharp drainage. They thrive in alkaline, gritty soil and rot in heavy wet clay. Once planted, leave undisturbed to naturalise. Excellent in pots, alpine troughs, and rock gardens. Grass-like foliage elongates after flowering then dies back by summer. Very hardy to -25C.
Yearly Lifecycle
Care Requirements
Light
Full sun essential; south-facing ideal
Full sun is essential. These bulbs need maximum light and warmth to flower well and ripen the bulb for next year. South-facing positions ideal.
Watering
None once established; must be dry in summer dormancy
No watering needed once established. Summer dormancy requires dry conditions. In pots, keep barely moist in winter, dry in summer. Overwatering is the main killer.
Fertilizing
High-potash feed after flowering while leaves are green
A light feed with a high-potash liquid fertiliser after flowering while foliage is still green helps build the bulb for next year. No feeding during dormancy.
Pruning
None; let foliage die back naturally
No pruning needed. Allow foliage to die back naturally after flowering. Remove only fully brown dead leaves if tidiness is desired.
Growing Tips
Sharp drainage is essential
These bulbs rot in wet heavy soil. Add grit or sharp sand when planting. Raised beds, rock gardens, and pots with drainage holes are ideal. If your soil is clay, grow in containers instead.
Plant deep enough
Plant bulbs 8-10cm deep in autumn. Unlike bearded iris rhizomes which sit on the surface, these are true bulbs that need depth for insulation and anchoring.
Leave undisturbed
Best left alone after planting. They naturalise slowly in well-drained spots. Lifting and dividing is rarely needed and can set them back.
Let foliage die back naturally
The grass-like leaves elongate after flowering and photosynthesise to feed next year's bulb. Never cut back while green. They disappear by midsummer on their own.
Spacing & Planting
| Plant spacing | 8 cm |
| Row spacing | 10 cm |
| Mature height | 13 cm |
| Mature spread | 5 cm |
Plant bulbs in groups of 10-25 for best effect, spaced 7-10cm apart. Looks best in dense drifts or in pots and alpine troughs.
