There are two common varieties of water iris -- the European white flag and the blue flag. Both make a striking addition to a garden pond. Other irises commonly referred to as water irises, such as the Japanese and Louisiana irises, are well-suited to boggy, shallow water areas and come in a wide variety of colours, shapes and sizes. Choose the right variety for your garden's growing conditions as well as for height, spread, foliage, texture, colour and bloom time.
Choose baskets that are wider than they are deep and large enough to allow for the growth of the plant's root system.
Line the basket with burlap and fill with aquatic planting media (you can substitute unscented cat litter). Place bulbs just under the surface of the media and top with a 1.25 cm (1/2 inch) layer of sand.
Place basket in shallow water on a shelf or in a pocket at the pond's edge. Water irises do best in water between 2.5 and 15 cm (1 and 6 inches) deep. If planting in a pond with fish, choose a shallow shelf that can be segregated from fish by building a dam of rocks.
Fertilise with fertiliser tablets made specially for pond gardens two months before blooming season. The season varies between varieties and climates.
Boggy or marshy ground
Dig out a shallow area of ground next to your pond about 15 to 20 cm (6 to 8 inches) deep and line it with a flexible plastic liner to retain water.
Add 15 to 20 cm (6 to 8 inches) of a soil mixture of one-half acidic soil (pH about 6), one-quarter heavy loam and one-quarter heavy fertiliser (rich compost or well-rotted manure). Plant iris rhizomes about 1.25 cm (1/2 inch) under the surface. Add a 2.5 to 5 cm (1 to 2 inch) layer of rich compost on top.
Fill with water. The bog must not be allowed to dry out.
Fertilise with well-rotted manure two months prior to blooming season.
In a shallow, decorative, watertight container, put in 15 to 20 cm (6 to 8 inches) of a soil mixture of one-half acidic soil (pH about 6.0), one-quarter heavy loam and one-quarter heavy fertiliser (rich compost or well-rotted manure).
Place the rhizomes about 2.5 to 5 cm (1 to 2 inches) below the surface of the soil.
Add up to 15 cm (6 inches) of water to the tub.
Fertilise the same as for pond gardens.
If planting more than one variety of irises, put them in separate baskets (or bogs) so they won't cross breed.
If planting in tub gardens, place the tub in its permanent location before planting. The location should be able to accommodate periodic draining.
In ponds or tubs, putting a small bunch of anacharis underwater can keep the water clear.
For pond gardens, fertilisers other than ones made specifically for ponds will foul the water and harm fish.