There are two arborvitae trees in my backyard that have ties in them to cinch in branches that were bent out of shape from heavy spring snow. Also, the previous owner implied, to keep these looking more dense and healthy. One of the arborvitae had been exposed to very wet conditions, sitting in pooled water, when the property had poor drainage. I think that has contributed to its unhealthy look overall. If I cinch these branches in more, is that healthy? This should make the tree look denser... I've included pictures of the ties that are in them now. The ties that are black feel like rubber. I don't know what they are. But, these seem to work the best. (Better than the twine.) Do you know what this black material is? How to acquire? There is quite a lot of it in these trees. (The previous owner is no longer available to ask.)