This is a spur of the moment contribution so excuse any half assed explanations but this is a general overlay of what I have learned, but as a general pretext, plants are just like you. Healthy plants need all their nutrients and a balanced diets of other trace minerals. If you uust shove your plants full of the main fertilizers its like giving them taco bell every day. More will be explained later but I will start with the basics.
Avoid all non Organic fertilizers. All you need for a healthy garden is blood meal, bone meal, kelp meal, normal fireplace ash, and assorted guanos for N-P-K(nitrogen-potassium-phosphorus) the three essential nutrients for plant growth and are on the front of all fertilizers, you literally cant fucking miss it.
Its really simple; follow the fucking directions on the box, if you overdo it you will fuck your shit up.
Apply nitrogen fertilizer AND ONLY NITROGEN during vegetative growth
As the plant enters the flowering/fruiting phase slowly ween out nitrogen(N) and start adding the phosphorous and potassium(P,K).
When using organic fertilizers the nutrients will NOT be readily available and will have to be broken down by microbes in the soil, because of this I would suggest buying exogenous mycorrhizae and azospirrilum.
These two bacteria help create a healthy biome to break down materials that will provide nutrients.
You also need to supplement assorted trace materials, most importantly calcium and magnesium which are available through various sources but I prefer Epsom salt and oyster shells.
Calcium is ESSENTIAL to plant growth and the amazing part about it is that your plant will only take as mich as it needs so you cant really oversupply plants like you can with fertilizers so apply liberally but make sure to watch soil PH if applying while plants are in ground rather than amending beforehand. Calcium will help encourage vigorous growth by allowing your plant to spend less energy supporting itself and helps make thick cell walls so the plant is more resistant to pests.
I really dont know what magnesium does so I cant say more on that but ive never not amended my soil with it so fuck it we both gotta look into it.
In addition to these two occasional application of organic unsulfered blackstrap molasses is amazing for your garden as the sugar is a great carbohydrate source, and also creates a breeding ground for beneficial bacteria in your soil.
Im bored now but ill check back later