Dry soil or boggy patch, knows just the flower to grow there.

It seems there's an iris for every occasion. Do you have a boggy damp patch that has acid soil? Then Iris louisiana, or the Japanese iris, is for you. Or perhaps you have a sunny, dryish spot with alkaline soil and you would like some flouncy colour in your perennial border? Then go for a cultivar of the bearded iris. And by colour, I mean serious colour of any combination.

Scrolling through the hundreds of bearded iris cultivars I was transfixed by the array of colours and intriguing names; some websites even let you sort by colour. One has a page filled with variations of black - inky blacks named "Black Suited" or "Before the Storm", blue-blacks such as "By Night" or even purple blacks like "Ebony Angel".

Don't get me started on birth years. You could choose an iris for a special someone based on the year the iris was bred; 1971 (my birth year) was a bountiful year for iris breeders, so there is an array for me to choose from, including a bronze-flushed blue and gold number named "Neon Rainbow" for an almost iridescent 70s day-glo effect.

October to November is prime iris viewing time. At The Sustainable Living Centre in New Lynn the Dutch irises we planted as bulbs are flowering around our food forest/orchard. They provide a delightful elegance and add spring colour while the deciduous trees are bare. Dutch irises require average garden soil, they're not too fussy. The plants will die back and shoots will emerge from the bulbs in late winter.


For a couple of years around her birthday, the previous chairperson of our board, whose name happens to be Iris, bought bulbs and rhizomes to plant in the garden. It's become a nice ritual for staff, and slowly the irises are becoming a spring feature in our garden. Pretty Japanese Iris ensata "Variegata" is also flowering. It has a reddish purple flower with striking evergreen foliage.

The main point of difference between irises is their growing system. Dutch irises (the ones we see as cut flowers outside the local dairy) are grown from bulbs which die back after flowering. Bearded, beardless and crested irises, on the other hand, fall under the category of rhizome irises. They are sold as rhizome divisions (a little like ginger root). Most of these irises are evergreens.

Louisiana irises, which are in the beardless rhizome group, are mainly water plants. The Louisiana iris originates from the gulf states of the Mississippi River, as the name suggests. They will grow in a wide range of situations, even if you don't have a marshy area beside a pond. According to the Society for Louisiana Irises, it will grow in an ordinary garden, as long as the iris gets two deep waterings a week in summer. They also love acidic, well mulched, composty soil.

The Louisiana iris flowers from mid to late spring. Then in the heat of summer they go into a kind of dormancy, with the leaves remaining as long as the rhizomes are mulched to protect them from the heat. In autumn they come alive again, and this is when they grow most actively. So regular feeding will make a difference to the health and vigour of the plant.

The bearded iris, on the other hand, enjoys quite a different approach to its care. The rhizome of this plant prefers to be perched above ground, with finer roots anchoring it to alkaline soil. Dig the roots into the top of the soil and pin the rhizome down on the surface until its roots are securely anchored.

Mulch is the enemy of this plant. The rhizome needs direct sun and air to avoid fungal problems. Mulch makes conditions too moist and will rot the rhizome. Every three or four years, the plants need to be dug up, with pieces of rhizome and new sprouting foliage divided and replanted. Discard the old pieces.

This is really only the tip of the iceberg when it comes to irises. I see why there is such fascination with these delicate beauties and the range is quite remarkable. The iris is one of the earliest garden plants on record, cultivated for well over 2000 years.

* Iris is the Greek word for rainbow.

* Orris root (from the German Iris germanica and the sweet iris I.pallida) is still used in gin for colour and flavour.

* In 19th century Germany, orris root was hung in beer barrels to keep the beer fresh and, in France, the wine fresh. The essential oil was used in perfumes dating back to ancient Egypt.

* There are up to 300 species of the iris genus.

* It is believed the true origin of the Fleur de lis was the yellow iris, Iris pseudacorus.

* That same iris can take up heavy metals and clean polluted waterways. Unfortunately this iris is considered an invasive plant by Biosecurity NZ.

Nurseries to visit:
* theirisgarden.co.nz
* theirisboutique.co.nz
* nikauhill.co.nz
Iris shows:
* http://historiciris.blogspot.co.nz/2012/07/iris-shows-2012.html

Mail order:
* irisgarden.co.nz
* bloomingbulbs.co.nz
* rivendellirisgarden.com
* Want more? Join the New Zealand Iris Society.