Organic vs synthetic fertilizers: which is best for cannabis?

Organic vs synthetic fertilizers: which is best for cannabis?
Miguel Antonio Ordoñez

When growing cannabis you can choose between organic and synthetic fertilizers. So what are the differences? Read more about this at CannaConnection!

Just like any regular gardener, cannabis cultivators have the option of choosing between organic and synthetic fertilizers for their crop.

Organic fertilization techniques traditionally call on the use of manure, compost, or leguminous cover crops to maintain soil rich and nutritious in order to maximize the quality of a crop.

Synthetic fertilization techniques overthrew these farming methods in the 19th and 20th centuries, and have become the standard in almost all kinds of agriculture.

However, as people become more conscious of the environmental complications of using chemical fertilizers, more and more people are turning back to the traditional methods of using compost or manure.

So what are the differences between organic and synthetic cannabis fertilizers and the advantages/disadvantages of both?



Fertilizers are generally considered to be organic if they are made up of purely animal or vegetable waste products, although fertilizers including rockdust may still qualify as organic.

Some examples of organic fertilizers include compost, manure, worm castings, alfalfa or bone meals, and fish emulsions.

There are many benefits to using organic fertilizers.

Organic fertilizers tend to improve soil quality over time, which is ideal for any long-term growers looking to utilize the same soil for multiple grow ops.

They tend to boast a slow, yet steady release of nutrients, which is great for any growers worried about overfeeding their plants.

Continued use of organic fertilizers also helps to improve water retention, airflow, and the overall quality/diversity of your soil.

Finally, they allow you to minimize your impact on the environment as they are less likely to cause nutrient runoff.

However, organic fertilizers also come with their share of disadvantages.

Because organic matter tends to take longer to break down, it therefore takes longer to be absorbed by plants.

This may prove problematic for any growers battling nutrient deficiencies mid grow, as the effects of new fertilizers may simply take too long to kick in and therefore allow plants to get damaged.

This process may be even slower in colder conditions, as the organisms responsible for breaking down the various components of organic fertilizers work less efficiently at lower temperatures.

So, if you’re plants are fighting particularly cold conditions, this may be problematic as the nutrients from your fertilizers might simply take too long to be absorbed by the soil.

Another major problem with organic fertilizers is that they increase the risk of introducing harmful insects and garden pests into your grow, which may be particularly hard to handle in indoor grow conditions.



Synthetic fertilizers, as the name suggests, contain chemical nutrients and have been specifically designed to contain exact concentrations of nitrogen, phosphorous, and potassium.

Synthetic fertilizers also boast a variety of benefits which may suit some growers more than others.

First of all, they are absorbed much more quickly than organic fertilizers, allowing you to raise or lower the nutrients in your soil more quickly.

Secondly, they allow you to have more exact control over the nutrient concentrations in your soil. As they have been specifically formulated, you can easily keep the track of how much of each different nutrient is in your soil, which is virtually impossible when using organic fertilizers (such as compost).

Synthetic fertilizers are also more affordable than organic fertilizers (both bought or homemade) and are widely available at grow shops and garden stores, making them much more accessible.

While that all sounds splendid, synthetic fertilizers aren’t without their limitations.

Synthetic fertilizers do not “feed” your soil, meaning they do not increase its quality over time. In fact, synthetic fertilizers tend to diminish the overall quality of your soil, which leads to nutrient runoff.

This results in nutrient loss and, more importantly, means nutrients work their way into the environment, which can have devastating effects on local ecosystems, especially when used on large-scale ops.

Also, as they are rapidly absorbed by your soil, your plants may be at risk of overfeeding, which may stunt their development.


Deciding on what kind of fertilizer you use depends on a variety of factors, including the size of your grow, whether you're growing indoors or outdoors, and the amount of time, effort, and money you’re willing to invest in the quality of your soil.

We generally consider organic fertilizers ideal for cultivators who are planning to manage multiple grows and aren’t short on time. They’re also great for cultivators looking to minimize the impact on the environment, which may be especially important in outdoor grow environments.

While they may be more expensive and difficult to use, organic fertilizers allow you to build out incredible soil over time, which will only benefit your future grows.

Synthetic fertilizers, on the other, are better suited to indoor growers looking to pump out big yields in a short period of time. They are readily accessible at almost any gardening store and are designed with exact nutrient ratios, giving you greater control over your grow.

However, one of the main downfalls of synthetics fertilizers is their effect on the environment, which we think any serious grower should be concerned about, especially as cannabis production expands around the globe.

Miguel Antonio Ordoñez
Miguel Antonio Ordoñez

Miguel Ordoñez is a long-time writer by trade. Utilizing his AB Mass Media and Communications degree, he has 13 years of experience and counting. He’s covered a wide array of topics, with passion lying in combat sports, mental health, and of course, cannabis.