Organic fertilizers are first of all the most respectful for the environment, as well as safe for the plants and us. Organic fertilizers are unlikely to damage the plant when given in excess, while this is rather common and often happen using chemical fertilizers.

It’s essential to provide plants with the essential nutrients they need and fertilize. Many novice growers tend to use industrial fertilizers in abundance resulting in serious problems and in same case the death of their plants. Plants in general are more tolerant with organic fertilizers, or rather we can say that organic fertilizers are much kinder to our beloved plants than chemical ones. Over-fertilizing is the worst thing we can do with any crop.

You may be interested in reading the specific article: “Growing hemp: essential nutrients and micro elements“.

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Any organic matter we add to the substrate decomposes, bringing nutrients to the soil. Some are more appropriate than others, let’s see them together:

COMPOST: it’s basically decomposed organic matter. It enriches the soil and can be prepared very economically using vegetable food waste both in the home and in the garden.

MANURE: it is an excellent fertilizer that helps condition the soil and provides everything the plant needs. Put one part for every ten of the mixture.Wiggle Worm Earth Worm Castings — 15 lbs – Earthworm Castings Organic Fertilizer for all purpose 

Price: $13.45


WORM HUMUS: it is one of the best fertilizers for cannabis, and more in general for plants. While large amounts can be used without danger to the plant, it should not be added in percentages greater than 30% of the mix.

This specific article may be worth reading: “Humus: what is it and how to make it

GUANO: they are seabird droppings. Although its composition is highly variable, it usually contains a lot of phosphorus. It is a fast-acting fertilizer * particularly suitable for foliar fertilization, to be sprayed on the leaves of the plant. It is sold in solid form to mix with soil, or liquid to mix with irrigation water or spray.

Down To Earth – High Phosphorus Seabird Guano (0-11-0)

Price: $69.72


BLOOD FLOUR: it is dried and pulverized slaughterhouse blood. It has a high nitrogen content and acts quickly (use 1 part per 100).

BONE AND CORNWALL POWDER: it is a fertilizer recommended for correct flowering thanks to its high phosphorus content. It releases the phosphorus slowly, so you should use a lot of it and mix it with the soil during preparation.

HAIR AND FEATHERS: They are a slow-acting fertilizer rich in nitrogen.

In order for the nutrients provided by fertilizers to be absorbed by cannabis, the pH (value that measures acidity or alkalinity) of the earth must be neutral or slightly acidic. the pH can be measured with litmus papers or with special kits that can be found in shops for aquariums and gardening.

The pH value of the soil should be between 6 and 6.5. It is common to find a land that is too acidic for cannabis, especially in areas where it rains a lot. You can increase the pH by adding quicklime, algae or even untreated wood ash, which is also rich in potassium.

It should be remembered that when watering plants, especially in pots, the nutrients are washed away with the water that comes out of the pot holes of the pot.

To prevent the plant from running out of food, it’s always advisable to add small doses of fertilizer, rather than adding them in large dosages once every while.