What do I secure to stop plant box rocking?

[diy457]

I have a trellis attached to a plant box and the plant box has become loose so it rocks back and forth under wind and with trellis topples over.

I thought id ask the forum geniuses how to secure the plant box so it stays a square and strong - what's the best to secure it? where and with what?

It's probably not a great video but im trying to work out how to make it strong - I tried a few things but it's still rocks.

I just want to strengthen the box at the moment.

I can upload a better video.

Video of box moving

Any advice?

 

[robinbanks]

Needs diagonal braces fitting to the sides. Remember from school, a teacher banging on about how strong a triangle shape is?

This is the reason gates have a diagonal piece of wood on the back:

Without this, gravity would drag the gate into a parallelogram

The wind on the trellis (as a lever) has done the same thing, left and right, to your box that gravity would do to an unbraced gate .

If you brace from the top (next to the trellis) down to the bottom (furthest from the trellis) both sides it will stop the box from deforming

Add braces (red) to box sides (blue). You can see the triangle formed by the box edges (bottom edge, back edge) and the red line; this will resist the motion of the trellis

A sheet material fixed to the side of the box, using screws in the corners of the sheet would achieve the same effect (also form a triangle that resists applied forces, notionally)

 

[diy457]

Yes, it worked. Thanks. My brother said the same but I wanted confirmation. Did a quick fix ill do proper one later with metal for long term.