In the Fall, I cut back my 8-10ft Musafolias to the ground and covered with mulch and leaves. At that time, as now, they were groups of large tuberous clumps that were above ground. Now, as I wait for them to come to life again, I am wondering if I should dig up and divide the clumps and replant them beneath the soil line. I wonder if the new growth will be strong enough from these above ground tubers, or need to be replanted?