Mixed Planting

[Hosta]

We have a large planter at nursery where I work  - 8ft x 4ft by about 2.5ft high 

We are going to plant it up with veg, being a complete beginner at this, was wondering if it would be okay to put in rows of carrots, onions and leeks together ?

Any special growing instructions ?

[Hosta]

[thifasmom]

according to the basic rules of companion gardening they are perfect bed fellows.

[Hosta]

Thanks  :)