Every year, my backyard got a lot of falling leaves. To put those leave into a container or trash can is always a challenge.
The trick to compress these leaves into the container is to compress it by the wall of the container. The basic idea is that since the leaves is adjecent to the wall, the friction will keep the compressed leaves in place instead of poping right back. If you compress the leaves in the middle, it usually pop right back. If you think about fluid dynamic, this is why the flows adjecnt to the wall are flowing slower.