Bearded irises are big, bold, beautiful plants that live for many years with minimum maintenance. Begin by preparing an appropriate container for your iris; if you’re growing a dwarf iris an eight-inch pot is sufficient. You'll notice when you receive your bulbs that they look like mini onions and it will be easy to see that the spike should point upwards when planting. However, you will need a 12-inch pot if you’re planting the traditional tall bearded iris. Plant the bearded iris rhizomes in the container, with the top third of the rhizome poking above the soil. Usually the rule of thumb when planting bulbs is that bulbs need at least 2 times their height of soil above them. Planting dwarf iris bulbs is fairly simple. According to Easy to Grow Bulbs, those living in … Growing Irises in Pots Your regional weather conditions determine when is the best time for planting iris bulbs in pots. The bearded iris does well in pots, and is available in dwarf and miniature varieties that are especially suited to container growing. Make sure the pot has good drainage holes and fill the bottom inch of the pot with gravel to encourage even better drainage.