Willow branches are used for weaving baskets on a loom. They can be obtained by using secateurs on a willow tree that has fully grown in a tree patch, using the Farming skill. This is only possible after you check the health of the willow tree. After doing so, one branch is produced every 5 minutes, up to a maximum of 7 at a time. This means that if you wait for more than 30 minutes, you will only be able to cut 6 before having to wait 5 minutes to cut another.