We can have frosts well into May up here, but usually our last one is around the end of April. I've got 2 maple stumps I dug in December (I thought I was moving
...not yet). They weigh 30-45 pounds apiece, and have since leafed out. I was moving them in and out of my garage almost nightly, but now I'm just throwing a tarp over them...my back hurts.
Dave