Made some containers, purchased cheap soil at supply store along with black cow, lime and fertilizer pellets. mixed that together and put in my containers and put my plants in the containers. 

I figured dirt is dirt as long as it had the correct nutrients in it. Not so with container gardening. Need to use potting soil. It is a special mix of this and that with fertilizer already in it for container growing.

Will be throwing  away about 15 cubic feet of dirt. along with black cow mix and fertilizer. 

You would think I would know better growing up on a vegetable farm. Guess I was not interested in it at the time. Plus I would be thinking of gardening at ground level. Stick the seed or plants in the ground and watch them grow.

Been doing a lot of research on container growing the last 7 weeks. Container sizes (Had those correct anyhow) Soil needed, watering, fertilizer, PH factor for each type of vegetable,

This past week I dumped the dirt I had in the cuke container 16x16x12 inches and lined the side and bottom with burlap then filled the container with potting mix with fertilizer to about 4 to 6 inches from the top and added a layer of small pieces of charcoal. I purchased natural charcoal and busted it up into small pieces. Then I finished filling container with potting soil. I watered that down good for the first soaking. In the mean time I screened some potting soil through a plastic container with 1/4 in holes drilled to use for seed starter mix. Seeds seem to have a difficult time pushing out of the ground with those little chunky nuggets they put in the potting mix. You can buy seed starter mix but I did not.   Dug down about 1/1/2 inch and replanted my cuke seeds in the starter mix. I planted Bush Crop Cukes. 

They claim burlap around and at bottom will prevent the plant from getting root bound. 

Why charcoal? I was reading and watching you tube about bio-char. My theory is the layer of charcoal 4 to 6 inches down will absorb a lot of water before it leeches out of the container. Now my other thought is using containers require watering often which leeches out the fertilizer in the container. Charcoal is a filter that captures a lot of junk that passes through it. The fertilizer that leeches down from above the charcoal will be captured and stored in the charcoal. So when the plant roots get down to that lever the will enter the honeycomb crevices in the charcoal and have adequate water and fertilizer to draw from stored in the charcoal. Will see if that theory works out.

I have some tomatoes and regular bell pepper plants that I will be building containers for and putting in my burlap, potting mix and charcoal about 6 inches down.

The tomatoes go by the name of Siberian Tomatoes. need to plant those seeds yet. The Siberians are suppose to be  cold weather hardy. Thought they would go good for the fall season which does not really get that cold until January of February. I also have some Rutgers about 3 inches tall ready to be set when the containers are done.

I had four boxes made, 2 for zucchini and 2 for yellow squash. They turned into a disaster with just dirt mix. They will be getting dumped and refilled with what I mentioned. Seed started 1 each of the squash. Will use the other two for tomatoes.

I have some leeks started also. Will need to build a box for those and fill it with the goodies.

Learn as I go, dump the failures and try again.