Iris reticulata has a reputation for being ‘tricky’, with flowers the first year and only leaves in following years. An acquaintance did an unofficial on-line survey of gardeners the length and breadth of Britain, and found no pattern between those who grew them successfully and those who struggled with them. So what is the secret for success?
Iris reticulata is a native of the Caucasus – Iran, Iraq, Turkey and Georgia – where it grows in the mountains. Here, it grows in well-drained (but not dry) soils, receives lots of sun, and gets blasted in the winter; these are the conditions we are trying to replicate. The ‘only leaves’ syndrome is caused by the bulb splitting into lots of smaller ones – this problem can be countered by not planting the bulbs too shallowly.
It will soon by obvious when the bulbs start to emerge whether you can expect flowers
The flowers of the specie type are a rich purple
However, there are many named varieties, and it makes sense to track down some reliable ones if you want lots to provide some early colour.
Iris ‘Cantab’ is pale blue
While Iris ‘Harmony’ is a deeper blue
Iris ‘George’ and ‘J S Dijt’ appear to be the same color as the type, although ‘George’ (in the foreground) has broader petals.
Iris ‘White Caucasus’ is the best white-flowered form, but I find it comes into flower just as the others start to go over.
Mine are all growing in a raised bed in a mix of good soil and horticultural grit, the sort of mix you would use for alpines. The bed faces due south and gets sun until the early evening in summer, and these conditions and aspect seem to suit them well.