Cannabis plants have different ideal NPK ratios at different stages of growth. This is why most nutrient kits give you multiple fertilizers with different NPK ratios.

What are secondary nutrients?

Nitrogen, Phosphorus, and Potassium are the primary nutrients of plants. The secondary nutrients are Calcium, Magnesium, and Sulfur. These are also essential nutrients for best cannabis nutrients but they need them in far smaller quantities.

• Calcium helps in root development and protein synthesis.
• Magnesium helps plants turn light into energy.
• Sulfur helps plants turn amino acids into proteins.

The micronutrient content in your fertilizer should be listed somewhere on the packaging or instructions. If you look at the back of this bottle of General Hydroponics BioThrive Grow, you’ll see it’s 0.5% Magnesium, 1% Sulfur, and has no Calcium.

What are cannabis micronutrients?

These are trace nutrients your plants need. Cannabis micronutrients are iron, manganese, copper, zinc, and boron.

• Iron helps with a lot of things. These include protein synthesis and chloroplast development. It also helps with energy storage.
• Manganese is important for photosynthesis. It also helps cannabis plants absorb nitrogen.
• Copper helps with photosynthesis and plant respiration and metabolism.
• Zinc helps activate enzymes that boost chlorophyll production.
• Boron helps the plant grow stable stalks.

What is cannabis nutrient burn?

Cannabis nutrient burn occurs when there are too many nutrients for the phase of growth. Nutrient buildup is harder to correct than deficiency.

Think about it this way. If you were to go to the local drugstore and take every kind of vitamin, would you benefit from all those pills? No, you would pee out the majority of the excess vitamins you were taking. Plants don’t have kidneys, so they get damaged by taking in too much.

It’s a classic rookie mistake to give your cannabis every nutrient you can get your hands on. You can absolutely give your plants too much. The best nutrients for cannabis are balanced nutrient ratios. Less is more.

Plants that are overfed will have an oversaturated dark green color with burnt-looking edges. The cannabis plant is trying to get rid of the excess, so it’s pushing it to the edges of the leaves. As soon as you see the first signs of nutrient overload, flush your plants. You can’t heal any damage done, but you can stop more damage from occurring. Overfeeding your cannabis plants won’t kill them, but it will make your yields smaller.