Primary purpose: Stretch against walking creases and maintain shape

Shoe trees - also called shoe wood when they are made of wood - help you with a natural problem of leather shoes: Through walking, the leather is compressed and stretched and continuously deforms in this way - walking creases are created this way and can be a bigger problem for leather shoes .

A shoe tree brings the leather back into its original, stretched shape. This then looks much more attractive when you take out your favorite shoes to wear them. While new, untried leather shoes do not show walking creases, leather shoes get their walking creases right from the first wear. These are also visible in the stretched state with shoe trees, but usually only minimally if the shoe trees are long enough.

If you have just slipped out of your leather shoes, the shoes inside are warm and filled with foot sweat. The leather is therefore quite elastic and this is the perfect opportunity to put in your shoe trees. So you should ideally not wait too long to insert your shoe trees into the shoes. But if it still doesn’t work immediately, just do it at the next best opportunity - because shoe trees also work on leather that has already dried.

A shoe tree is made to keep a shoe dimensionally stable and reduce creases. It is unsightly when shoes are pressed inward, e.g. if you should stand on them - intentionally or not: new creases form and the leather is unnecessarily stressed. If it happens accidentally a few times, it is normally not so bad. But it is bad for the shoes if the mentioned stress becomes a habit or the norm.

Secondary purpose: Absorb sweat and antibacterial effect

If you have been out and about in your shoes and insert wooden shoe trees after taking the shoes off, then the following also happens:

Wooden shoe trees will absorb some of the liquid and thus spare the leather lining from some of the foot sweat. Sweat is bad for leather because it is alkaline. This shifts the pH value of the leather from the optimal, slightly acidic range into the alkaline range, where the leather is more likely to deteriorate. Despite this advantage, a wooden shoe tree can only absorb a limited amount of sweat, so in my view this benefit does not carry much weight.

Antibacterial effect very small

Even less significant is the antibacterial effect of some types of wood, which is created by active ingredients in the interior of the wood. Cedar wood is best known for this and is advertised accordingly. However, the scent quickly fades, so this benefit is only short-lived.

You can reactivate this effect afterwards by sanding the wooden surface of your shoe tree a little. However, sanding makes the shoe tree a little smaller each time. Over time, if you sand off too much overall, your shoe tree would no longer stretch your shoes enough.

I myself would not want to pay extra money for such an antibacterial effect of the wood. That is why, for me, the wood is very secondary in this respect, and advertising copy to the contrary would make me suspicious or cautious. Accordingly, I would not buy cedar shoe trees because of the antibacterial effect of cedar wood, but simply because it is a good wood like any other.

Variants of shoe trees

Spiral shoe trees (also called spiral spring shoe trees)

I would not recommend this type, because the flexible, long metal spiral can leave noticeable marks in some shoes. This happened to me with a pair of boots, where the metal spiral pressed from the inside up into the leather and then left an unsightly crease on the shaft leather on the outside.

This risk is there in principle if you want to use spiral shoe trees universally for all your leather shoes. But if you first check whether the metal spiral does not press too much into the leather, then you can judge individually for each pair of shoes whether you use these shoe trees here. Overall, such a spiral shoe tree is suboptimal, especially in the heel area: there you only have a single pressure point, so the pressure is not distributed evenly. However, a spiral shoe tree is better than no shoe tree at all, if it leaves no pressure marks in the shoe.

Screw shoe tree (also called twist tree or threaded tree)

This shoe tree is similar to the spiral shoe tree, except that the flexible spiral is replaced by an extendable metal part. Along this metal part, the wooden piece at the rear end can be gradually turned in and out, which adjusts the length. A greater length then creates more tension at the front of the shoe, but can also create too much tension at the heel. There is also a single pressure point there, which covers a bit more area than a spiral shoe tree.

Spring wooden shoe tree (also called bow tree or clamp tree)

This shoe tree has a lot of wood volume and a lot of material, which is why it is relatively heavy. It fills the inside of the shoe extensively and the pressure is distributed quite well over large areas.

Such a shoe tree has one or two main springs in the longitudinal direction, and these serve the main purpose of reducing creases from walking by stretching the shoe. In addition, such a shoe tree usually has a secondary spring at the front in the transverse direction across the width, which ensures that the shoe is stretched a little sideways in the toe area. However, this is only a small bonus and serves only a little to support the main purpose of a shoe tree, which is to reduce creases from walking. So you do not need to be concerned if your shoe tree has no sideways spring: that is not a must for a good shoe tree.

Hollowed-out shoe tree variants

These shoe trees can come in different variants as screw shoe trees or spring wooden shoe trees. What they all have in common is that the shoe tree is hollowed out at the front bottom so that air can circulate better and mold is therefore even less likely. This also makes them lighter, and such shoe trees additionally look more elegant.

However, the hollowed-out shape requires more effort to produce, and the pressure at the front in the lower area is distributed a bit unevenly toward the outer parts of the insole, which should not be a problem.

For example, the shoe brand Saint Crispin’s uses such shoe trees, as do some bespoke shoemakers. I myself know such shoe trees in a version without any springs and also not as screw shoe trees. They are simple shoe trees that can be folded together once, but there is no room for length adjustment: they have to fit, which is especially suitable for bespoke shoes.

Three-part wooden shoe tree

This shoe tree has, so to speak, the greatest possible wood volume, the most material, and depending on the type of wood used, potentially also the greatest weight. It stretches in all directions, but especially in the longitudinal direction of a shoe, to combat creases from walking.

The front part is inserted into the shoe first, and in the second step the rear part is placed into the heel area. The middle shoe tree part is then inserted between these two outer parts. The more you press down from above, the more the two outer parts move apart in the longitudinal direction and the more they thereby stretch the shoe.

Compared to the screw shoe tree, you do not have fixed, individual stages for the amount of tension here, but can control the amount of tension very flexibly. - Similar to the advantage of lace-up shoes over buckle shoes. That is why this is probably the best shoe tree overall that you can get.

If shoe trees create too much pressure against the leather shoe

This risk to your leather shoes exists with shoe trees that are too large or too long, which then exert too much stretching force on the inner lining leather and may even cause cracks. In the better case, the shoe is only stretched a little in the longitudinal direction, if you are lucky.

In practice, I have not had any problems so far when the shoe tree was only slightly too large for the shoe. That was at least the case with the spring wooden shoe trees. With screw shoe trees, you can manually adjust the pressure applied, and I can imagine that this is where you are most likely to accidentally apply too much pressure. However, if you insert the screw shoe trees carefully into your shoe and, if necessary, correct the length, then you will manage that too.

Material

The material is secondary for a shoe tree, since, as already mentioned, what matters is the shape-retaining effect of shoe trees. However, I would prefer wood over plastic, simply to better prevent possible mold growth: wood can absorb moisture, whereas plastic cannot. This is not to say, however, that you are guaranteed to get mold with plastic shoe trees. After all, the leather lining also absorbs moisture and later releases it into the surrounding air. You can also get mold with wooden shoe trees. In my view, wood as a material has only slight advantages overall, but you can still take those advantages with you if you choose wooden shoe trees instead of plastic ones.

As already mentioned, cedar wood is advertised quite strongly because of its antibacterial effect, though this is rather unjustified from the standpoint of practical convenience. I myself am not opposed to cedar wood, and the vast majority of shoe trees I own are indeed made of cedar wood. However, you can just as well use beech or another type of wood. The biggest difference I have noticed between types of wood so far is weight: I have a pair of particularly light spring shoe trees from Materna, which do not have any special shape, meaning they are not hollowed out in the front either. I suspect they are made of the especially light material poplar wood, but I cannot say for sure. In any case, because of their light weight, they are excellent as travel shoe trees. If you do not have any such ones and want to go on a trip, plastic shoe trees are also quite light and therefore very suitable for travel. However, I also have no problem taking the normal, heavier spring shoe trees made of cedar wood with me when traveling, though this probably simply depends on what your trip is like in concrete terms.

Complications with size

A shoe tree should of course fit the shoe. Unfortunately, different shoe tree manufacturers use different size specifications. Therefore, it is somewhat sensible to inform yourself more precisely before buying which shoe tree size you need for your own shoe size. You will notice a shoe tree that is too small most easily because it does not properly stretch the shoe, especially in the walking-crease area. Shoe trees that are too large or too long can be recognized by the great pressure they create in the shoe. Here you should be careful not to overstrain the leather.

Personally, however, I am relatively relaxed when it comes to large shoe trees, since nothing has happened to me so far. - Even though some spring wooden shoe trees have put quite a lot of tension into the shoe, but still not too much in the end. In terms of length, I consider screw shoe trees the most flexible, so that you can make the most adjustments with them. - Even if they are too small in width, you can usually extend them quite a bit, so that they still stretch your shoes in the end, even though they are actually too small.

Evaluation

Personally, I would rate the possible shoe trees in terms of shape as above in ascending order according to the sequence. That means: avoid spiral shoe trees if possible and regard the three-part shoe trees without any springs as the best. Since the latter are significantly harder to get in practice, I usually stick with normal spring wooden shoe trees, although I also do own screw shoe trees and especially appreciate that I can strengthen the tension at the front of the shoe very well.

Shoe trees make a difference

Condition of shoes after use without shoe trees

As you can see, the leather of a shoe is pressed inward and creases are moderately pronounced. In addition, the toe caps are shaped relatively strongly upward according to the deformation of the leather while walking.

Condition of the shoes after a week in shoe trees

For this comparison image, I put shoe trees in the shoes and took them out again after about a week. I also used a little care cream here already. As you can see, especially one shoe has returned to shape and is no longer deformed inward as it was a week earlier. In addition, the creases in both shoes have been reduced and the toe caps are no longer bent upward quite as strongly, which improves the situation of the walking creases once again. The shoes are still slightly curved, because this curved shape supports the rolling motion of the foot during walking by offering less resistance to the walking movement.