I am going to attempt to grow tomatoes in a container.
The container that I have is a half whiskey barrel. I picked it up from my brother-in-law, who wasn't using the one that was left with his new house. It did have dirt in it when I picked it up. The dirt appears to have been potting soil of some kind, as I can see the styrofoam flecks in it an so forth. Unfortunately, I have no idea as to how old the dirt is, and therefore how possibly depleted it is.
In addition to this, I live in MN. The naturally occurring soil up here is black. Perfect for farmland and so forth (which there is a lot of). The soil is very loose and loamy.
My question is: what kind of soil is best for growing tomatoes?
I am interested in growing organically, so any fertilizers or plant food I would like to be organic in nature. Is the dirt that was in the container safe for planting in - possibly adding some manure or compost to it? How about the naturally occurring dirt? I imagine it's good for planting in, but I don't know what the specific nutritional needs of tomatoes are, and what kind of soil I should be looking for.
Keep in mind that I am a 'newby.' I have never custom-mixed soils before, and I'm a little intimidated by that prospect. However, I'd like good soil for my tomatoes, so I'll try to listen well regardless.
Thanks for any helpful advice you can give!