As a rule, you should fertilize at least three times a year; spring, summer and early fall.
Here's a way to get more life out of an old hacksaw blade. Mount it on the side edge of your workbench with about half the width of the teeth sticking up over the top surface. This will give you a handy cutting tool. Make sure that the location of this cutter is both easily accessible as well as away from frequent brush up traffic.
For certain types of rooms and some aesthetic tastes, exposed concrete flooring is a nice option. You can get concrete with a pigment color integrated into the material, you can paint the concrete, or you can simply use a clear (non-toxic) sealer for a more modern or industrial look