The Labor Day holiday comes at the perfect time for busy gardeners! Bearded Irises should be divided every 2 to 3 years, and Daylilies need division every 3 to 5 years. Late summer is the best time to do this, so make a morning of it and do both at once!
Bearded Iris is very easy to dig up, because the rhizome sits at soil level. Carefully dig it up, keeping as many roots as possible, and wash it off. Then check the rhizome carefully for soft areas and small holes. Remove all of these undesirable areas with a sharp knife, then divide the remaining rhizome at its natural joints (shown at right with a red arrow). Trim the foliage back to about 6 inches, and re-plant the new rhizomes.
Like everything else about Daylilies, division is very simple! Just dig up the plant, taking care to keep as many of the roots intact as possible. Then plunge two garden forks back-to-back through the center of the plant and gently pull them apart, dividing the plant in two. Repeat until you have smaller clumps. Trim the foliage back to about 12 inches and re-plant the new clumps, hilling up the soil and fanning at the roots.
Now that you have many more new Bearded Iris and Daylily plants, you might consider creating an accent planting of just these two perennials. They both appreciate sunshine and good drainage, and bloom successively, with the Daylilies often encoring to keep the Irises company! This way you can dig up and divide the entire planting every 3 years, and keep your garden growing in beauty.