Bearded iris (Iris germanica) is also called German Iris and common flag. It is believed to be an indigenous plant to regions in the Mediterranean and southern Europe. The fragrant, eye-catching 4- to 5-inch-wide flowers of bearded iris come in a wide variety of colors including yellow, white, blue, lavender, purple, brown and nearly black. Bearded iris are accustomed to dry growing conditions and are usually difficult to grow in Orlando because of the high rainfall. By planting bearded iris in pots, you can control the growing conditions better than planting them directly in the ground.
Place growing containers, like 2- or 3-gallon pots, in a suitable location in your garden. The temperatures in Orlando can get well into the 90s, so place the growing containers in your garden were they will be provided morning sun and partial afternoon shade.
Fill the growing containers until they're approximately 1/2 full with a good quality potting soil. Make sure the growing containers have at least four drain holes each. If they do not, use a drill and masonry bit to drill holes in the bottom of the pots. Bearded iris do no like having soggy roots.
Mix 1 to 2 Tbsp. of all-purpose fertilizer, such as 10-10-10, into the soil at the bottom of the pot. Scoop in more potting mix into the pot so it's about 3/4 full.
Plant one to two of the bearded iris rhizomes horizontally on top of the soil if using a 2-gallon pot. If using a 3-gallon pot, place two to three bearded iris rhizomes on top of the soil. An iris rhizome is an underground, fleshy stem that spreads out and multiplies. You can purchase bearded iris rhizomes through your local plant nursery or garden center.
Scoop in potting mix to fill the growing container full of soil. For planting bearded iris rhizomes in Orlando, cover the bearded iris rhizomes with no more than 1/2 inch of potting mix. If necessary, remove the bearded iris rhizomes from the soil and reset each so they are covered with no more than 1/2 inch of soil..
Water each of the bearded iris rhizomes thoroughly with a steady stream of water to soak the roots and help settle the rhizomes. Bearded iris rhizomes should begin sprouting within a week to 14 days, depending on soil and weather conditions. Keep the pots well moistened until the rhizomes are established, then water only when the soil in the pots gets dry. Do not allow the soil in the pots to become sodden wet.
Fertilize the bearded iris every two weeks, beginning two weeks after you have planted the rhizomes until a month after they cease blooming. Use a 6-10-10 or similar low-nitrogen fertilizer and follow the specifications so you will know how much fertilizer to use per pot.