Iris are pretty spectacular. They originate from the Mediterranean and Middle East.
We have a nice established clump in the corner of the back patch right near the gate. Psychedelic blues and purples.
Iris are perennial, relatively hardy and easy to grow if they are in the right location.
They do well in well-drained to dry soil in full sun.
Iris grow by rhizomatic spread. The Royal Horticultural Society recommends planting iris rhizomes from July to October, spacing pieces 1 foot apart (30cm). It’s an easy distance to figure mentally if you simply imagine a standard ruler size.
The most important thing is to ensure root sections are partially exposed to the sun. This is crucial, and burying the roots under the soil will eventually kill of your iris.
Adding sand and grit to ground can be beneficial for iris, particularly if planted in ground that is rich and moist, as they need free draining conditions..
Divide clumps every 3 to 5 years. Plants can be divided from early to late summer.
Dividing Bearded Irises
- Ideally divide 6 weeks after flowering – around the end of August. This allows plants to re-establish and settle before winter.
- Before dividing dig a hole large enough for the rhizome and roots. Add grit.
- Root sections should be placed at soil level. Firm well and water thoroughly.
- When you dig up the larger established clump, cut fans of growth on root sections with a sharp knife or secateurs. Each section should be at least 6 inches (15cm) long with a fan growth of leaves. Cut away two-thirds of the leaves on each cutting to reduce wind rocking.
- Tall bearded iris should be placed at least 12 inches (30cm) apart.
Notes of Interest
- RHS Garden Rosemoor is developing a collection of water irises at Rowden Gardens in Devon. The collection aims to have more than 70 cultivars. Go to http://www.rhs.org.rhs/rosemoor
In 2020 the iris were spectacular and bloomed for most of the month of May. By 30 May all flowering had finished and I cut off the last of the spent flowerheads. We will need to divide the iris this summer – partly to spread the joy further down the flower beds, and partly for the health of the plant as they are starting to crowd one another.
In the third week of April 2019 the back patch bearded iris was in bloom. Awesome! Flower spears standing upwards of 3 feet high, with glorious extravagant blooms.