Leather and suede, being natural products, will have a degree of stretch inherent within the material. This can be encouraged and utilised by wearing the boots in, causing body heat to soften the leather, and pressure from wear causing them to stretch where needed.
Suede and Leather will only stretch where pressure is being placed on it – the material cannot “overstretch” above what is required. As with many other materials, Suede and Leather will give up to the point required by the person wearing them – they become ‘your boots’!
The Suede and Leather won't grow more than the room required (as there is nothing causing them to grow bigger than needed!)
To avoid the ankles or calf softening in areas not required, or slouching/ wrinkling, always use boot trees to keep the boots upright and in a natural position! If boots are left to sag/ fold over when not in use, this can cause the ankle area to soften when bent.