i just got a free locust tree and haven't planted it yet. is it too late to plant it ? if it is too late how should i prepare it to over winter above ground? i live in northern colorado on the front range @ 5,300 ft.

Hello, I just had a complete new waste line installed from my house to the property line. The new waste line is PVC and it is very close to a tree I had planted, about 3 feet. The tree was a purple plum tree "crautus vesuvious", The contractor said it was ok, since the waste line was no longer clay, so it won't crack with the roots. But I got nervouse and had it removed anyway. Boo hoo, now that area looks so empty, and it needs something. I was thinking of planting another tree, a smaller one like maybe one of those Brugamasia "angel trumpets". and trying to push it further away from the line, 3.5 to 4 feet. Even though the waste line is no longer clay, and Brugamasia's don't get huge, I am still conflicted about the root issue. I've heard of people planting trees in plastic pots with the bottom cut out. This is supposed to contain the size of the tree, and controll root spreading. Does anyone know anything about this. Like I said, the area i want to replant a smaller tree in is aproximatelly 3.5 feet from the new sewer line, and I just want to be safe.