The amount of literature about garden, flowers and agriculture is huge. But it seems, that the community struggled into describing the optimal conditions for garden cultivation. Sure, in most books about the topic all the details are mentioned but not a clear priority list which fulfills academic standards.
The most important thing about plants is, that they are dependent from light. There was a small story available in which sailor on a ship had the task to transport plants over the ocean. What they have done was put the valuable freight in the room near to the potatoes. The room was cold and a bit dark. The sailors had the assumption this would be the optimal conditions for the plants. After one week most of the tomato plants had become yellow leaves and after two weeks the plants looked unhealthy.
A simple but not often cited recommendation is to put plants no matter which type it is into full sunlight and let them there as long as possible. If the plant gets more sunlight, especially the light at noon which is very strong the plant will like it very much. The leaves will become green, and the biomass will grow.
Some people beliefe, that plants needs to be protected from the light. No they don't. Plants are different from humans and animals. Humans need to be protected from sunlight because the skin isn't able to protect from the rays. If a human sailor sitts at noon in direct sunlight he gets burned and will become ill very fast. Plants under the same condition will grow very fast.
The funny thing is that apart from this simple rule no other recommendations are available to make the plant's life comfortable. The sort of the ground, the amount of the water, the amount of fertilizer and the date on which the plant is cut back by a human is not relevant. If these features are not perfect, nobody cares. The only thing what plants didn't like is if they are put into the dark. This will kill them for 100% certainty.
From an scientific point of view, the most important device which is needed by professional gardening experts is a light measuring device. This device can tell the human if a condition is the right one or not. The relationship between the numbers on the instrument and the condition of the plants are proportional. Which means, more light is better. If a plants is located in half-shadow the best idea is to put the plant to a position which has more light. And if the plant is in the maximum light condition, the best idea is bring the plant to a place near to the south in which the average light amount is higher.
The easiest condition under which gardening is possible is the dessert under full light. Making plants grow in a dessert is a win win situation. It is not possible to make such a project a failure. To prove this thesis we have to find somebody who lives in a Oasis and who has problems with this plants. It's a joke, because we didn't find such guy.