Karen - jackmanni superba considered a "group C", so you want to cut it to the ground in early spring- just above a set of buds as they begin to appear, allowing it all spring/early summer to grow new stems and leaves. ours is just beginning to bud out. we always leave about 18 inches of the hardened main stems to deter slugs from eating them... in theory of course. last time we cut one of our "group C's" all the way to the ground the slugs had a field day with it. the new shoots would grown 1/2 inch. they would eat it. grow another 1/2 inch, they eat it. I call it the, "push pop affect". we finally had to dig it up and put in in a pot to protect it a little in order to give the brand new shoots a fighting chance. we have four main stems on ours this year, each about the diameter of a pencil, producing about 18 individual stems. its in its 3rd year and we are very impressed with how its filled out. but for some reason the leaves are turning white and dropping off from the bottom up. the upper leaves are in superb condition however.
