If you’ve ever been confused by gardening articles that say irises like wet soil, dry soil, acid soil, alkaline soil etc, join the club. The fact is, all of the above statements are true to some extent. There is an iris for almost any soil or climate; it’s just a matter of selecting the right one for your situation. Please buy a pH test kit at you local hardware store or nursery, it will really help you understand your soil.

Warm, dry winters, wet summers

Louisiana’s are your best bet, if your soil is alkaline, prepare a special place and add acid potting mix and/or sulphur. Alternatively grow your Louisianas in large pots with acid potting mix.

Louisiana’s and Japanese will do well, alsoTall Bearded and Spurias. Make sure your Tall Beardeds are very well drained and there is no moist mulch over the rhizomes. Try Pacific Coast’s in well-mulched soil with good summer drainage and good winter moisture. If you have frosts, Sibericas will do well also, keep moist till after flowering.

Tall beardeds and Spurias in well drained soil. Try Louisianas and Japanese in pots of camellia potting mix, sitting in shallow water. If you get winter frosts, try Sibericas, Dwarfs and Medians as well.

Cold wet winters, dry summers, alkaline soils.

This is where Tall Beardeds and Spurias thrive, and Dwarfs and Medians, especially if you have good winter frosts. Although many books say bearded irises grow well up to a pH of 7.5, many iris growers here in South Australia grow them very successfully at pHs of about 9 (very alkaline). If you want to grow Louisianas and Pacific Coast irises, use pots with acid potting mix. Put the Louisianas and Japanese in pots of camellia potting mix in shallow water, such as a paddling pool, also, check that your water is not too alkaline.

Cold winters, wet winters, dry summers, acid soils – Pacific Coasts, Louisianas and Spurias will do well but you must mulch your Louisianas well and keep them watered well in summer. Siberica and Japanese Iris will grow if well mulched and watered through summer. Dwarf, Median and Tall Beardeds, are all good also, but may need a little lime.

These will grow in almost any climate. Dormant varieties tend to do better in frosty areas and evergreens in warmer areas. In areas of very low humidity a few varieties may not open their flowers properly. In sandy soils incorporate a lot of organic matter into your soil.

Daylilies are drought tolerant but do much better if well fed with organic fertilizer and are well mulched and reasonably watered.

Rock Gardens - Shorter small flowered Daylilies with their finer foliage look lovely in rock gardens, as do Dwarf and Median Irises (in frosty areas). If the garden is well drained and hardly watered, the aril bred irises are a good choice. In moister rock gardens try Pacific Coast Iris if you have acid soil.

Lightly Shaded Spots – This is where you can grow Iris Unguicularis (which will flower through winter) and Daylilies.

Sunny but Damp Spots – This is heaven for Louisianas, Japanese and Daylilies, and some species iris. In cold climates the Siberian Irises also do very well.

Hot Dry Spots – This is where the Bearded Irises thrive (the Aril-Breds will be especially happy). They look great when mixed with roses, lavenders, etc. Take care to ensure that no mulch covers the rhizomes of the irises as this may inhibit flowering and induce rot. Spuria Irises,  being taller, look great in the centre or back of the garden. If there are some spots which get a bit more water you can mix in some Daylilies, ensuring they are well mulched.

The Tropical Look - Daylilies with their hot colours and bright green stroppy foliage really add to the scene, plus they will flower for long periods, whether in full sun or light shade.

Louisianas will look good in a damp sunny spot.

The Pond – Daylilies look great around the edge of the pond. If your soil is acid, the Louisianas and Japanese will thrive right at the edge. If your soil is not very acid, put your Louisianas and Japanese in pots of acid potting mix and half immerse in the pond. Further out from the edge you can plant Spurias and Bearded Iris if the top of the soil is not damp all year round. Also Pacific Coast Irises, look nice around the front (in acid soils). Sibericas look good in a damp area in cold climates.

Cottage Garden – This is where Tall Bearded Irises can really add to the look. Lots of roses, perennials and masses of irises for the "Monet" look. Just make sure that the mulch and ground covers don’t shade the rhizomes too much. In cold climates some Medians and Dwarfs Irises look good at the front of the garden. If you maintain adequate summer moisture, your reblooming irises will often flower twice a year, once established.

Naturalizing – Spuria Irises naturalize well. They will die down in summer after flowering and come away with the winter rains. Many bearded irises also do well without summer moisture, especially Aril Breds (which will die down in summer).

Coastal gardens – remember that beach front areas often don’t get as much winter chilling as a kilometre or two inland. Thus in areas such a Sydney and Perth (and right on the beach front in Adelaide) tall bearded irises may not always flower. Spurias may do well, Daylilies and Louisianas (acid soil) will thrive, if there’s plenty of organic matter and moisture.

POT CULTURE

We do not recommend growing Spuria or Siberica irises in pots.

Tall Bearded Irises - a 30cm (12") pot or larger is recommended. Fill with quality potting mix and plant the rhizome 1-2cm deep. Water more often than if they were in the ground. Every couple of days in very hot weather. While the pots like to be somewhere sunny in summer they like to be cool in winter. So make sure they are not against a north facing wall through the winter, they won't get cold enough. Put the on the south side of the house/shed, under a tree etc from about May -August so they can be nice and cold, but don't allow then to dry out completely. Fertilize well twice a year.

Dwarf and Median bearded iris culture is similar but they can be grown in slightly smaller pots. However ensure that the pots don't dry out so much that the soil repels water.

Louisiana Iris - These need very large pots. Try to get a variety that is not an extremely enthusiastic grower, there are some smaller varieties available. The best pots are plastic pots without holes in the bottom. With these use a sharp knife to make a few holes about 2/3 the way up the side of the pot. This way it is harder for the irises to dry out. If using a pot with holes in the bottom sit the pot in a pond or a dish of water so the water comes at least 1/3 of the way up the pot, however it is best if the actual rhizome is above water level. Use an acidic potting mix (azalea / camellia mix) and add some cow manure, up to 50%. However if you will be putting our pot in a decorative pond, leave out the cow manure as it will cause the pond to often turn green. Fertilize in winter and after flowering, with camellia fertilizer. If your water is very alkaline the leaves may start to turn yellow, add some sulphur to acidify the soil. Ensure that the soil stays damp. If in water the pots can stay there for a long time, there is no need to lift at certain times of the year. However they are gross feeders and appreciate a repotting very 2-4 years.

Japanese Iris - Pot as for Louisiana irises (above) in pots with holes in the bottom, but remember these irises go dormant over winter. They prefer to be drier at this time, so lift the pot out of the water and keep the pot just damp, not wet. If you have wet winters just leave the pot somewhere cool, where it can get rained on.

Pacific Coast Iris - Pot in large pots of acid potting mix. Keep damp but not wet, a little drier over summer but not totally dry. These do not always thrive in pots but some people have good success

Daylilies - These do  well in large pots with good potting mix, regular fertilizing (2-3 times a year) and regular watering.

REBLOOM

A number of TALL BEARDED IRIS now flower for a second time , later in the season. For most this occurs about 4-8 weeks after the autumn rains, where summers are dry. Irrigating over summer (not more than once a week), will help induce rebloom but make sure bearded iris don't have their rhizomes covered with damp mulch. The amount of rebloom that occurs for any given cultivar depends on i, the genetic tendency for rebloom, ii, the pH of your soil, iii, the amount of water, both natural rain and irrigation, iv, other climatic factors.

Most  modern DAYLILIES are multiple rebloomers. Strongly recurrent cultivars may have up to 5 rounds of bloom in a season, once established.