I love the landscape timbers you used for your beds. Did you use 3 1/2" screws to attach the layers together too? Were they long enough? I can see where they'd be long enough for the corners.

I have a couple timbers I was thinking of using for a bed too but didn't think 3 1/2" were long enough.

3 1/2" screws are fine as long as you counter drill 1 1/2" deep with a drill bit slightly larger than the head size of the screw.
You will need an extended screwdriver bit to drive the screw home.

Ok, now that makes sense! That is definitely something I can do. I have a nice box of 3 1/2"screws I was lamenting ever needing again. OMG another project for next summer. The list just keeps getting longer and longer!