Iris time

Sunday, 26 October 2008

October is iris time in Sydney gardens: the ones that do best are the 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 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 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 (Rosmarinus officinalis), sage (Salvia officinalis), perennial wallflower (Erysimum mutabile), statice (Limonium perezii), Dianthus, lavender, Artemisia and sweet Alice (Lobularia maritima), which all have a similar 'dry' 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.

Louisiana irises, on the other hand, have a lusher look, and combine well with more tropical-looking foliage, shrubby salvias, Abutilon and some of the classic perennials which thrive in Sydney: such as Aquilegia, species geraniums and Silene.

One of the attractions of irises is the rainbow of hues in which they can be had - the variety is truly mindboggling - so they can really add impact to a colour scheme in your garden. To increase your stock, 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.