Every August, the WTIS hosts its rhizome Sale.
Normally, one third of the clumps in the WTIS Iris Garden are dug, cleaned, disinfected, and dried prior to the sale. This year, we will be digging everything!
Irises are normally dormant during the heat of the summer ... making this the best time for digging and dividing them. Tall bearded rhizomes can be out of the ground for a while, but should be planted by early November to give them a chance of growing roots before the ground freezes.
Our 2018 Rhizome Sale will be on Saturday, August 25th from 9:00am until 3:00 pm at the Pickering Center in Germantown, TN ... 7771 Poplar Pike.
Iris need at least a half a day of sun. All bearded irises demand sharp drainage while most beardless irises thrive in moist soils and appreciate some shade when the soil is dry.
Bearded irises prefer a slightly acid 6.8 soil pH, but are fine if the pH is only slightly off. In the midsouth, peletized lime will likely be required to adjust pH.
In the midsouth, bearded iris rhizhomes must be exposed to the sun and kept dry in order to thrive. Do not plant them deeply. Conversely, beardless irised should be planted deep and kept moist until new growth is visible.
Irises are generally planted 12 to 24 inches apart. The closer they are planted, the sooner you will need to divide them which should be once every 4 or 5 years.
Regardless of type, irises do not like much nitrogen. We typically use a light 6-12-12 fertilizer in March and a second agound June 1.