When starting out on my gardening adventures I've took a lot of losses in plants from not knowing these basic concepts of gardening. I thought I could just put a seed in regular backyard dirt, water it, and it would thrive, but that is not always the case. Let's face it, backyard dirt is most of the time corrosive with very little to no nutrients for plants to thrive.
Macronutrients
The three main nutrients or macronutrients for all plant life to grow are on ther periodic table of elements (I flunked chemistry); nitrogen (N), phosphorus (P), and potasium (K) known as NPK. Plants need more nitrogen, and potassium than phosphorus when they start growing in the spring and summer, and more phosphorus than nitrogen and potassium in the late summer of August to fall for flowers or fruits to grow big.
When you buy a bag of soil, or nutrients, you'll often see three sets of numbers on the bag or bottle with a dash in between them for instance; 4-1-3. This is the NPK ratio of macronutrients. The first number 4 is the higher number or ratio of Nitrogen in the soil meaning there is more nitrogen than phosphorus, and potassium. The second number is the ratio of phosphorus for less phosphorus than nitrogen and potassium. The third number is potassium for a little less potassium than nitrogen.
The amount of potassium should never be more than nitrogen unless in the flowering or fruiting stage. If buying a bag or of dry pebble or powder macronutrients, you can sprinkle it right over the soil at the nutrient companies recommended amount, or over the mulch you use, or mix it and water it into your soil so your plant roots will instake the nutrients they need right away to sustain the stems, leaves, and fruit. Not only will you need the NPK macronutrients, but you will also need the secondary or micronutrients for all stages of growth.
Secondary Micronutrients
Secondary and micronutrients are like the other minerals and vitamins for plants to be healthy throughout their growth cycles with no leaf color changes known as leaf deficiencies in the beginning stages of vegetative growth before the fruiting or flowering cycle. Those secondary micronutrients are: calcium, magnesium, sulfur, iron, zinc, man- ganese, copper, boron, molybdenum, and chlorine.
If you notice any leaf color changes in the beginning vegetative growth stages, and you're feeding your plant the proper NPK macronutrients, it is more than likely because there is not enough of either of those secondary micronutients. The question a lot of people ask is if they feed their plants the proper amount of the micronutrient, will it fix the leaf discoloration?
The answer is no, but the next set of leaves will grow beautifully and if you maintain the proper levels of micronutrients, your leaves will stay a solid green color through the whole vegetative growth stage. There is nothing you can do about leaf color changes in the late summer to fall because the nutrients in the leaves feed the fruits or flowers.
Soil Types