Every so often, someone asks a question suggesting that he fears shoe trees will stretch out and harm his shoes (especially if they're suede).
The answer, as always, is that unless the tree is grossly mismatched to the size of the shoe (like, somehow forcing a size XL shoe tree into a size 7 shoe, not that this is something one is likely to manage), shoe trees will not damage shoes. Not calfskin shoes. Not horse ass leather shoes. Not suede shoes. Not shoes made from the skin of the rare fire-spitting zebra lizard of the south-central Garnath Valley, near Mount Kolvir. Shoe tree use will tend to be beneficial to shoes. It will not hurt shoes.
Thanks so much for the quick response! Time to order some new trees.