"Iris time"

October is iris time in Sydney gardens: the best are the tall bearded irises and Louisiana irises.
Sunday, 04 October 2020        

Unusual near-black tall bearded Iris

Since late August, I have been enjoying the blooming of my shade-loving Iris japonica and Iris wattii plants: these are woodland irises that have pretty white or pale blue ruffled blooms held above their lush green fans of foliage. They look delightful growing beneath early spring-flowering shrubs and mingled with sprays of forget-me-nots and primulas. October sees the arrival of some different species of Iris, which thrive in sunny spots: tall bearded irises and Louisiana irises.

Many irises prefer cooler climates, but the tall bearded type and the Louisianas do well in most of our suburbs, though they are polar opposites in their requirements. Both love sun, but tall bearded irises want a dry, mildly alkaline, well-drained position without fresh organic matter, whereas the Louisiana irises love moisture and rich soil, and can even be grown in dams and ponds!

Clumps of irises look magnificent amongst the many shrubs and perennials which are in flower in October. The tall bearded irises form an excellent partner to roses at this time, and they are also look effective grown with other 'Mediterranean'-style plants that thrive in Sydney in hot sunny spots: such as rosemary, culinary sage, perennial wallflower (Erysimum mutabile), statice (Limonium perezii), Dianthus, lavender, Artemisia and sweet Alice (Lobularia maritima), which all have a similar 'dry climate' look. One of the best bearded irises is the original Iris germanica flag iris, with rich purple blooms, which begins to flower in winter in Sydney and continues throughout spring. It is a plant which has been grown for many years in country gardens and passed on from gardener to gardener (pictured above).

Louisiana irises have a lusher look than the tall bearded irises, with much longer, rich green leaves and larger, more dramatic blooms, and they combine well with more tropical-looking foliage, such as that of Canna (which enjoy a similar moist, sunny position) and with shrubby Salvia, Abutilon and some of the classic perennials which thrive in Sydney: such as Aquilegia and species geraniums.

One of the attractions of irises is the rainbow of hues in which they can be had - the variety is truly mind-boggling - so they can really add impact to a colour scheme in your garden. To increase your stock or bearded irises, divide the rhizomatous clumps after flowering (around November or December). Do not plant the bearded iris rhizomes too deeply. Remove unsightly leaves on a regular basis, as the older foliage can become quite squalid. Lousiana irises also need to be divided every few years: March or April are good months to do this job.

These irises don't flower for a long time in Sydney gardens but they bring rich colour at an exciting time of year! Interestingly, there are some varieties or tall bearded irises (called the remontants) which rebloom in late summer or autumn, which have an added appeal. Many of these were raised in the USA in the 1920s and 1940s, and in recent times breeders have become interested in this characteristic again and have developed more of them. Some suitable ones for Sydney include 'Victoria Falls' (light blue), 'Cascade Pass' (white), 'Harvest of Memories' (clear yellow), 'Perfect Couple' (mauve, white) and 'Total Recall' (pale yellow). The flowering stems of irises can be picked for vases; some varieties are even perfumed!

This blog was originally posted on 24 October 2008; updated 4 October 2020.


 Reader Comments

1/3  Laurel - 4179 (Zone:11A - Sub-tropical) Monday, 05 October 2020

Hi Deirdre, thank you for your wonderful blog. I love reading it, it carries me out into a beautiful garden and straight away I feel relaxed. I live in Brisbane, love Louisiana irises but our rain has become less consistent here. I find they are very tough but unless they get a feed and water leading up to flowering time, they won't flower. But when they do, the beautiful flowers are worth the water bill. My yellow ones have just started, next will be the wedgwood blue and then multi-coloureds. They sound marvellous, Laurel. They do seem to like food and water! Deirdre


2/3  Bob - 2567 (Zone:10 - Warm Temperate) Monday, 05 October 2020

Hi Deirdre my Irises are flowering well this year with a little more rain than usual. All yellow except one blue/white one. When not flowering they do fill up hot dry areas with their foliage. They seem to tolerate neglect which I am good at. Yes the bearded ones are tough and I like the fans of foliage during the rest of the year. Deirdre


3/3  Valerie - 2121 (Zone:10 - Warm Temperate) Tuesday, 06 October 2020

Those near-black irises look amazing. There are some pale purple bearded iris here about to flower which I use as a bit of a ground cover. A friend said that sometimes the flower becomes white after a few seasons. This has actually happened to a few and the white flowers are larger. Have you heard of this? Hopefully the yellow ones will stay yellow. Yes it does seem as if they change colour sometimes but I don't know if this is just that a rogue white one multiplies or comes up from seed and takes over. Deirdre


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