Reeds can be mined instantly with anything.
When the spot a reed is placed in becomes unsuitable, such as when the support is removed, the reeds will uproot and will drop as an item. Reed will not immediately uproot when all adjacent water is removed, but will do so when it next receives an object update or varying tick.
Reed can generate naturally next to water, as two, three, or four meters tall. Rarely tall reeds can be found if generation chooses to generate another on top of one already generated.
Reed naturally grows to a height of three meters, adding a meter of height when the top reed has received 16 varying ticks (i.e. every 18 minutes). Bone meal does not work on reeds to speed its growth. It does not need radiance to grow.
3 reeds makes a Paper.