I'm no expert, but speaking from personal experience, plain garden soil tends to get really hard over a couple of years, and it needs more "fluff" in it.

I am very hesitant to use peat, vermiculite, perlite, for various reasons....which is pretty much what's in potting soil. My plan in my next containers is to use lots and lots of home-grown compost, and lots of straw. I'm hoping this will prevent the hardness. Plus, if you do something like this, you should turn and incorporate more of the natural stuff in every year in your containers.

My rubbermaid tubs cracked over a couple of years. This year, I'm going with a metal stocktank. Good luck!.

I'm sure others will chime in here soon.

Additional info: the product I purchased is Miracle Gro Organic Choice Garden Soil (for in-ground vegetables, fruits, flowers & herbs).

Unless you're out to challenge yourself by seeing how well you're able to deal with significant adversity, I'd skip the "garden" soil, which is often black sand with a small organic component added. How water behaves in container media is markedly different than how it behaves in the earth, and understanding how to deal with how water behaves is probably the most important part of becoming proficient as a container gardener. An ample amount of air is as important in soils as an ample amount of water. Too much water and the plant won't have enough oxygen to carry on efficient root function. If particles are too small, as in the garden soil, they will pack together with no room for air, and hold too much water. Finding the balance is where you fund success.

I'll link you to a thread that will help you understand the specifics about what I touched on. There is lots of information there, and some recipes that give you some good starting points. I hope you find it worth the read.

Al

Here is a link that might be useful: More about soils if you click me!