It can be a challenging task to cut tall grass with the help of a reel mower. A reel mower cannot be set very high, as in the case of a powered mower. But in case you still want to use a reel mower, it is advisable to set the height of the reel mower to 5 or 6 inches or the maximum cutting height and continue with the mowing. This will ensure that you get a neat and tidy look with the reel mower too.