My Soil Mix for containers for herbs and veg

[Tarragon2017]

I have decided to keep it simplish and use a 1/3 coco coir . 1/3 grit and 1/3 multi purpose compost.

If you disagree or think I should change the ratios then please let me know.

Also with the fact that grit and coco coir is used I assume that I will need to use a fertlizer more regularly although Herbs dont need 2 much fertlizer

Please advise