The bearded iris is one of the most popular, among the over 200 types of irises. Irises are propagated in two ways -- by bulb or by rhizome. The bearded iris is grown from a rhizome, a long bulblike tuber. It blooms in early to mid spring, depending on the weather and location. Some varieties offer a second blooming during the summer. It grows up to 48 inches, depending on the variety. The three petals that hang downward give the appearance of a beard.
Choose rhizomes that don't have bruises, cuts or other damage, from the nursery or garden centre. The bearded iris rhizomes should feel firm to the touch. They are available for fall planting.
Pick a garden container that has drainage holes. Clay containers are porous, therefore the soil dries out quickly, requiring additional watering. Plastic containers hold soil moisture for a longer period of time.
Pour a non-soil potting mixture, from the nursery, into the garden container. This type of potting mixture contains vermiculite, perlite and sphagnum peat moss, which keeps the soil moist and well drained at the same time. This is optimal for bearded irises in containers. Leave about 3 inches clear at the top of the container..
Dig a hole for each bearded iris rhizome that is as deep as twice its diameter. Potted irises are planted closer together than when they are planted directly into the ground. Space them about a half inch apart. They should never be touching, however. The pointed end of the rhizome should face upwards.
Push potting mix over each planted hole. Press lightly over the potting mixture to work out any air pockets.
Water the newly planted rhizomes until it drips out of the drainage holes. Keep the container indoors, or in a protected area, until the last frost has passed in spring. Place the potted bearded irises on your patio, porch or in any location that receives full sun during the day. Water the bearded irises when the soil feels dry.
Potted bearded irises need no fertiliser. However, if you replant them in the ground after the spring growing season, you may include a low nitrogen fertiliser, such as 8-10-10, mixed in the soil.