Low retaining block wall footings

[Cjbamf]

I am laying my blocks flat over a 10m run holding back roughly 300mm of soil.
How deep should my trench be and how deep should my concrete base be?
On the width I have gone for 415mm in the base.
Thanks

 

[Mr diy a lot.]

100mm ish concrete footing for small walls in stable ground is adequate. No need to over do it - it’s hardest holding anything back. With laying bricks flat too it’s going to be already a pretty heavy duty spec for just 300mm of soil.