[iandromiskin]

I made a rectangular box for planting a few day ago, mainly as a box for securing to a wall for planting, but I found it looks just as good as a standard window box, so I thought I'd run with the idea. The only problem is the window sill is one of those modern concrete jobs and although the window box will sit on it securely and is heavy enough I'am just a bit worried that is might slip off in a good wind or something, so I was wondering if anyone had any ideas of how to secure this box to the sill ?

[Sb]

Use a 1 x1 or 2 x 1 wooden lath cut to just a touch wider than than the recess of your window. Then tap this down into the recess of the window with a rubber mallet. This is a bit trial and error as you may have to trim the edge of the lath if you find it too tight. When in place you now have something you can screw into without boring the sill, chipping it etc.
Attach one of these small L brackets to the window box, then screw the L bracket to the lath.



Bobs your uncle.