What can I grow?
If you’ve ever been confused by gardening articles that say irises like wet soil, dry soil, acid soil, alkaline soil etc, you are not alone. 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 from your local hardware store or nursery to help you understand your soil.
See below to learn what will suit your garden, including what you can grow if you are limited to a potted garden.
Warm, dry winters, wet summers
Louisianas are your best bet for these conditions. 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.
Cool wet-dry winters, wet summers, acid soil
Louisianas and Japanese will do well in these conditions, as do Tall Bearded and Spurias. Wet summers can be a problem so make sure your Tall Beardeds are very well drained and there is no moist mulch over the rhizomes. Try Pacific Coasts 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.
Cool wet-dry winters, wet summers, alkaline soil
Tall Beardeds and Spurias in well drained soil as wet summers can be a problem as above. Try Louisianas and Japanese in pots of camellia potting mix, sitting in shallow water. If you get winter frosts, try Sibericas, Dwarfs and Intermediates as well.
Cold wet winters, dry summers, alkaline soil
This is where Tall Beardeds and Spurias thrive, as will Dwarfs and Intermediates, 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 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, but check that your water is not too alkaline.
Cold 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, Intermediate and Tall Beardeds are also suitable, but may need a little lime.
Limited space, potted gardens