Nightmare soil in the garden of eden

[Highonash]

Hi everyone,

This year me and a friend, both indoor growers decided to try out guerilla growing. We searced high and low and found the perfect spot, cleaned it up set traps so we knew if anyone had been there etc. We're growing KC mango and Nirvana afghani special, about ten plants. As we dug the first hole though we found that the soil was thick clay, and at about a foot down solid rock. We haven't been able to find a spot that's nearly as perfect, so I was wondering if anyone had any drainage tips or something like that. If I pput the plants in large partially buried pots would I decrease my yield due to restricted root growth?

Thanks.