Rosie Lerner

August 2003
Q. My Siberian iris plants grow and bloom well, but the plants have a dead spot in the center of each clump. What do I do? — Caryn Hildreth, Lafayette, Ind. A. Many perennials, including iris, grow in an expanding circular pattern. This is their way of spreading to new locations. This growth pattern usually leaves behind a dead center, which works to the benefit of the plant since the new growth is more vigorous […]
July 2003
Q. How deep should mulch be at the base of a tree? I usually put a light coating around the trunk, in a circle, but I see some professional landscapers making big mounds. Does that keep more moisture in? — Shirley North, South Bend, Ind. A. Generally, a layer of mulch should be 3-6 inches deep, not a volcanic pile like you see around some trees! Even at this reduced depth, it should be pulled […]
Jun 2003
Q. My iris were beautiful with lots of flower buds this year, but just about the time they were in full bloom, the heavy rains came and knocked all the tall, blooming stems to the ground. Is there any way to prevent this? — Wendy Lacrosse, Fort Wayne, Ind. A. Many plants can be pinched early in the season to increase branching and reduce lodging, which is the fancy word for crashing to the ground. […]