Choosing and fitting
How do I pick a size?
Match the tree size to your usual shoe size. Each size spans a small range and the spring takes up the difference, so if you are between two, take the smaller one. A tree that is too long strains the heel counter, which is worse than one slightly short.
Will they stretch my shoes?
Not at the correct size. A shoe tree holds a shoe at its intended shape. A shoe stretcher is a different tool with a screw mechanism for deliberately widening. If a tree feels like it is straining the seams, it is too big.
Can I use them in trainers and boots?
Yes. Trainers benefit in particular, because synthetic linings hold moisture worse than leather does. For tall boots, a tree keeps the foot of the boot in shape but will not hold the shaft upright, which needs a boot shaper.
Using them
How long do I leave them in?
At least overnight, ideally a full 24 hours. For longer term storage you can leave them in indefinitely, which is the best place for both the tree and the shoe.
My shoes got soaked. Do I put the trees straight in?
Not straight away. Let the worst of the water go at room temperature, away from radiators, for an hour or two first. Cedar absorbs a lot but it is not a towel, and forcing a tree into a sodden shoe can distort it.
Do I need one pair per pair of shoes?
For the trees to do anything they have to be in the shoes, so yes, ideally. If you are buying one pair, put them in whichever shoes you wear most.
The wood
The cedar smell has faded. Are they finished?
No. The aromatic oils are still there, the surface pores have just closed up. Rub the wood with fine-grit sandpaper for a few seconds and the scent returns. Repeat every year or so.
Should I oil or varnish them?
Never. Any finish seals the wood and stops it absorbing moisture, which is the whole reason to buy cedar rather than plastic. Keep them dry and bare.
How long do they last?
Years. The wood does not wear out in normal use, and the scent is renewable by sanding. One pair should outlast several pairs of shoes.