Monday, March 5, 2012

Lord Howe Island Wedding Iris

Dietes robinsoniana ,Lord Howe Island Wedding Iris
Most people probably don't realize that Lord Howe Island is part of New South Wales. It always comes up on the weather map between Brisbane and Sydney and the air temperature is somewhere between both cities. The most famous native plant of Lord Howe is the Kentia palm (Howea fosteriana) and this Iris comes a close second. However, ask any nursery grower about it and they will probably tell you it is tricky to produce in any quantity. Reason being is that in its native habitat it grows in pure sand in the full force of sea wind or eeks out a living clinging to the side of a mountain. Thus in a nursery situation it needs to be kept on the dry side or in a very sandy potting mix. In the garden it grows to be a handsome clump forming plant of about 1.5 metres tall with many stems bearing clusters of pure white flowers in early spring. The seed produced by the pant is enclosed in a capsule which is usually ripe around this time of year. I have just planted some of the seed collected over the past week.
The clump as it matures grows "fans" of new leaves which often have exposed roots like stilts at their base . It is possible to cut these off to grow new plants and these are best potted into pure sand. Though it is a very easy care garden plant, especially in breezy coastal gardens, it is a favourite of snails which are able to find a safe haven amongst the leaves. Occasional pruning and clearing the clump of old brown leaves helps keep it looking good.