Q&As/Bulbs and Tubers/Dutch Iris Plants
I have a small plot of about 100 purple Dutch iris plants. Each one produces 2-3 flower heads per stem. As one flower dies another blooms. My question is; do I have something unusual and unique or is this the norm with Dutch iris? Nobody I have asked seems to know.
While it would be wonderful for your Dutch irises to all bloom at the same time, what you describe is quite typical for these bulbous irises.
To grow and flower at their best, Dutch irises require a light, well-drained soil in a full sun position. Avoid excess watering and do not fertilise with high nitrogen fertilisers. The regular addition of compost to your iris plot should be sufficient to encourage strong healthy growth.
Bulbs can be lifted and replanted every few years, particularly if you notice flowers are becoming smaller or if the bulbs are not producing as many flowers.