Outdoor Grow Holes

I’d like to know if I can plant my seeds directly into my native soil or if it’s better to use a store bought soil mix?
– Horsemeat Henry

Dear HH,
Interesting nickname. It is possible to plant into your soil but not nearly as effective as actually digging out a hole and filling it with a loose airy mix. The bigger the hole you dig, the more room for roots to expand and thus the more you will harvest from each plant. Outdoors in full sun, I recommend a minimum of three feet diameter and three feet deep but like I said, the bigger the better. Growers have been known to rent a rideable backhoe to excavate huge holes for their plants
Fill the hole with your soil-less mix (peat or coco works well), plenty of compost and worm castings and then add whatever other amendments you wish to benefit from. These include greensand, bat or seabird guanos, beneficial mycorrhizae, dead fish at the bottom of the hole and even the placenta fro a recently born baby. All of these things will provide a steady diet of soluble nutrients for your plants as they grow.
The best thing about having your own mix in the hole instead of native soil is the level of drainage and porosity of the mix to allow air to reach plant roots. In subsequent years, you can mix in nutrients to the mix and place cured compost directly on the surface as a top-dressing.