Dethatching: Can be done by use of a power rake or tine dethatcher. For most cases a tine dethatcher is enough as the power rake goes deep and can tear up some of the turf at the same time. If you are planning on seeding using a power rake is a good idea otherwise only use it in extreme thatch conditions. A little thatch is normal and necessary to keep a lawn healthy. A thin layer of thatch protect the soil and roots, however to much thatch can be a problem and needs to be removed. When excess thatch builds up it causes drainage problems and keeps nutrients, fertilizers and most importantly water from reaching the roots.