a long post about my experiences (I know most of you already know this, but it is superimportant, so sorry if it is a bit boring):
The most important thing about gardening - and I am not saying anything that many generations of gardeners have not known:
SOIL. SOIL. THE PERFECT SOIL!
You need to create the perfect soil. If you can do that, everything elsw will be easy. That is my experience.
I have grown the same plants 20-100 meters from each other (at various locations): one in (sometimes raised) compost-beds (always growing something in the beds, no disturbance, no digging, no herbicides, pesticides, fertilizers, etc) and one in the native soil and the experience is always the same. The ones that have good soil (and mind you, creating good soil takes years but you can speed up the process!) grew big, healthy, the taste was wonderful, usually very few problems, bugs and no need to do anything else than sowing, watering and harvesting; while the others grew much smaller, had less taste, got "sick" easily.
I have come to the conclusion that the best way to grow vegetables is in beds made of compost (good, quality compost is key!) - and you can grow big amounts of food in a surprisingly small area. You need to mulch the beds sometimes (depending on the climate) with grass/leaves etc; you need to grow something in them always, nonstop, even during winter, so that the biology in the soil gets fed, you must not disturb the soil (no digging or anything like that, and if it is not a rootveg you should even leave the root in the ground untouched-it keeps the good microbes and small things in the soil alive). If you can do this, you will have wonderful soil in a short time. These are now wellknown principles but we must never forget the basic rules:
- no disturbance
- no monocultures: as many types of plants as possible
- no bare soil
- always keep growing something: roots in the soil all the time
and if you can create your own compost, that is the best (fall leaves are bagged here and I can get as much I need for free, but you can also get plenty of stuff other people do not need, like coffee grounds, spoilt hay, fruit pomace, stable-bedding whatever.
If you have great soil, you already won and gardening will be easy
SIDENOTE: Fruit trees grow in many more types of soils quite well, but they also do much better if you strive to create good soil for them: grow a mix of cover crops around them (eg alfalfa, clovers, grasses, phacelia, even wildflowers, weeds, and cut this crop once - twice - thrice a year and mulch around the trees with it to keep them weedfree and fed. And that's it.