Pro-Mix Outdoor OR Pro-Mix Contaner??

Hi there, I'm doing my first grow this summer with Dutch Passion's Auto Mazar strain. I am doing it quite discretely so I am digging holes and lining them with 5 gallon grow bags with drainage holes and filling them with my growing medium. For nutes, I am using the General Organics Starter Kit Box. Should I use;

PRO-MIX ALL PURPOSE OUTDOOR PLANTING MIX:
http://www.canadiantire.ca/AST/browse/2/OutdoorLiving/Garden-Care/SoilsMixes/PRD~0594551P/Pro-Mix+All+Purpose+Outdoor+Planting+Mix,+28+L.jsp?locale=en

or

PRO-MIX ALL PURPOSE CONTAINER PLANTING MIX:
http://www.canadiantire.ca/AST/browse/2/OutdoorLiving/Garden-Care/SoilsMixes/PRD~0594552P/Pro-Mix+All+Purpose+Container+Planting+Mix,+28+L.jsp?locale=en

They both sound like they have benefits to each, for example, the outdoor planting mix contains mychorrizae, and the container planting mix contains extra water retention. The water retention would be good for me because I do not plan on visiting my sites daily, although I will be checking on them a few times a week. I do not quite understand what the benefits of mycorrizae are but I have heard it is really good..

Using the grow bags in the ground, would I benefit more from the mycorrizae or the water retention?

I know there are many better soils and things I could use such as Fox Farms Ocean Forrest and others, but for accessibility and price reasons, I have narrowed it down to either of these, so if you have any input please share!

The names should give you a clue. Are you growing in containers or in the ground? Mycorrhizae? Itty-bitty bugs to massage the roots and.................ever watch Futurama? Did you see the episode where Fry gets parasitic worms from eating a vending machine sandwitch? Same principle except these bugs are nice.

Geezer thanks for the response. Well I'm planting in the ground but in grow bags so I was thinking the drainage in the bags would be more comparable to a container.

nipple fuck!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

if u plan to go 2-3 times per week water retention wont be an issue, even in containers. Better soils, sure as far as having other amendments and nutrients mixed already, but promix does a good job as long as you supplement nutrients, which you'd have to do with fox farms anyway after a month or so because most of the soils nutes would have used up by then

thanks a lot mr. marijuana!