There is nothing unusual about the dietes flowering at the moment, but don’t let the fact that it is much favoured by amenity landscapers put you off. The reason it is seen so often in shopping centre garden plots is because it is tough and easy care.
It is a South African wild iris. Originally it was thought to be a moraea – commonly known as peacock irises – but that family grows from corms whereas the dietes forms rhizomes. Its flowers link it to moraeas, its rooting structure to the iris. Apparently the word dietes means ‘having two relatives’. ‘Grandiflora’ just means large flower.
The foliage is narrow, upright and pointed and it is evergreen. For most of the year, it just looks anonymous and not very exciting but it has such pretty flowers at this time. These are short lived but, as with many other irises, there is a succession opening down the stem. If the blooms remind you of an exotic butterfly, you may be pleased to hear that it is sometimes referred to as a butterfly iris. It flowers best with sun. While the plant will grow in relatively shady positions, you won’t get anywhere near as many blooms so try for full sun or somewhat dappled light.
As a garden plant, unless you want your place to look like a supermarket carpark, veer away from mass planting in favour of interesting combinations. I think it looks wonderfully effective planted with the tractor seat ligularia (Ligularia reniformis) but any contrasting big, luscious foliage is going to work.
First published in the Waikato Times and reprinted here with their permission.