can i put weed in my coffee grinds

Use Coffee Grounds As An All-Natural Cannabis Fertiliser

Coffee grounds are an often overlooked, all-natural, and practically free fertiliser. Here’s how to use them in your cannabis garden.

It may come as a surprise to many, but every time you empty your coffee grounds into the bin, you are effectively throwing away a very cheap, effective, and natural fertiliser that could be used to nourish your cannabis garden or indoor growing operation. Not only that, but coffee grounds can also help to cover up obvious smells and defend your crop against parasites and several other pests.

Coffee grounds are easily accessible and may appeal to a wide variety of growers, especially those who are environmentally minded. Coffee grounds are entirely vegan, and using your own grounds or those sourced from the local economy means minimising the transportation involved. Organic coffee grounds can also be used for those who are especially concerned about pesticide use and aim to keep their garden completely organic.

Here are some of the main reasons why using coffee grounds in your cannabis grow is a fantastic idea.


Adding coffee grounds to your soil and compost mixes will add to the acidity of the soil. Cannabis plants thrive in an environment that is slightly towards the acidic side of the pH scale, preferring levels of around 6.0–6.5. Soil pH that is either too high or too low will impede the growth of your plants, so it is important to monitor these levels closely. Coffee grounds can be used as a “pH down” product, acting to reduce the pH of your soil if it is too alkaline. Additionally, it’s entirely natural and won’t harm the environment when disposed of later down the line.


Every time you remove the grounds from your coffee machine, they can be added directly to your compost bin. This waste material contains nutrients that will keep your cannabis plants healthy and vibrant. When added to a compost bin, as opposed to being dropped directly into the soil, coffee grounds serve as a green waste, which can then be mixed with carbon-rich brown waste such as straw and wood ashes. Such a mix is excellent to generate the heat needed to break down the materials into a good-quality compost.

Coffee grounds provide noticeable levels of nitrogen into the compost mix. This key mineral is vital to plants as it is a major component of chlorophyll, the green pigment that plants utilise in order to conduct photosynthesis. Using coffee grounds will offer your plants a good supply of this mineral and will help to avoid any potentially damaging deficiencies during the grow cycle.


Perhaps one of the most challenging elements of growing cannabis is pest control and management. Many small creatures have an appetite for the nutrients within the cannabis plant and can do a great deal of damage to a crop when attacking in numbers. If spotted early, many invasions can be dealt with, although preventative measures are much more effective than curative ones. Coffee grounds offer multiple benefits when it comes to preventing pests from obtaining a foothold.

Firstly, the acidity of the material is reported to help stave off parasite infestations. Secondly, the small and sharp grounds have a micro-abrasive property. This means that insects making their way towards your plants via the soil may be put off due to the sharp minefield of coffee grounds that obstruct their path.

As well has offering defence against critters, coffee grounds are also said to assist against fungal invaders too, such as Fusarium, Pythium, and Sclerotinia.


Worms are an important asset in many cannabis gardens, and act as little compost producing machines. Keeping worms for this reason is known as vermiculture. The worms add the organic materials they are given and their poop, or castings, are used as compost within the garden. Coffee grounds can be fed to worms, as long as they are given other organic materials to form a balanced food intake that isn’t too acidic.

Are you currently throwing your coffee grounds in the bin? Well, you might want to put them to better use. They can serve as an excellent fertiliser.


This post is focused on coffee grounds for your marijuana grows (and its pros).

Coffee ground’s an abundant organic-material source, ideal for adequate vegetative behavior of marijuana plants; coffee contains many of the minerals required by crops, and high acidity – very useful when growing in alkaline soil/substrate.

This way, many growers use coffee grounds to improve their crop yields; let’s focus on coffee properties – ideal partner for cannabis.

  • 1 Compost
  • 2 Nutrients
  • 3 Acidity balance
  • 4 Insect repellent
  • 5 Worm food


Its nutritional content would be enhanced and supplemented; coffee could be added to ecological and chemical compost – cheap, simple, fast way to improve your crop compost.


Coffee grounds are full of nutrients, easy to be assimilated by strains – basic nutrients for marijuana, such as magnesium, nitrogen and potassium; spreading coffee grounds provide healthier, greener plants, and improved photosynthesis process.

Acidity balance

As previously mentioned, coffee increases substrate acidity – if soil acidity’s excessive, an alkaline substance’s added (powdered lime): soil acidity would be stabilized, and the strains would take advantage from coffee benefits without the negative effects of acidity.

Insect repellent

Coffee grounds can also be used as organic natural insecticide, improving plant resistance against insects, fungi (Fusarium, Pythium and Sclerotinia) and plagues – red spider, slug, caterpillar, snail; very good ecological anti-plague option – unbeatable price.

Worm food

Coffee grounds could be poured onto garden compost bin to produce quality compost thru organic waste; very useful for vermiculture – compost production thru earthworm excrements: this process provides earthworm humus – concentrated earthworm excrement (after organic feeding); this humus contains ideal nutrient levels for optimum plant development, and microbes which decompose the soil in more beneficial ways for crop feeding.

As previously mentioned, coffee grounds are multifunctional substances for cannabis crops – just enjoy coffee-ground benefits.


Chic gault 10 April, 2019, 11:26 pm

Got four glueberry x critical kush in 25 ltr pots,with coco,coffe grounds substrate ,will let you know the results

This post is focused on coffee grounds for your marijuana grows (and its pros). Coffee ground’s an abundant organic-material source , ideal for adequate vegetative behavior of marijuana plants; coffee contains many of the minerals required by crops, and high acidity – very useful when growing in alkaline soil/substrate