Heirloom organic non-GMO seeds vs Hybrid

[Amanah]

I have been toying with the idea of planting a 4' X 4' garden.

The idea is to build a wooden box on the ground and fill it with a mixture of:

* Blended Compost
* Peat Moss
* Coarse Vermiculite

I had not given any thought to the seeds I would use though, and now you have given me something else to think about.

I would like to grow tomatos, cucumbers and maybe melons.

The main problem I have is that my yard has a ton of trees, bushes, plants and shade. I have yet to figure out what spot would get the optimum amount of sun.