Can You Use Manure To Grow Cannabis?

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Added 29 November 2021


Cannabis can be grown in several ways, including organic and inorganic methods. 

While inorganic methods include using chemicals to feed the plants, organic methods use manure and other fertilizers. 

So, can you use manure to grow cannabis? 


You can use manure to give your cannabis plant the proper nutrients and minerals effectively. Manure is rich in vital nutrients and minerals that get passed on to your cannabis plants, especially during the vegetative stage.

The result?

You grow healthy cannabis plants and get rewarded with bountiful buds!

In this article, let’s take a look at how you can use manure to grow cannabis.

Benefits of Manure to Grow Cannabis

Manure for cannabis

You need the proper nutrients to live a healthy life — proteins, fiber, minerals, etc. Similarly, your cannabis plant also needs nutrition to grow and produce buds. The better the fertilizer, the more the yields. And, manure can help you get what you want effortlessly. 

Plus, that shit (literally!) is cheap. Growers spend hundreds if not thousands on fertilizers to get good yields, but plants don’t care about all that. As long as you give them what they need, they will grow well whether you use cheap manure or expensive commercial fertilizers. 

However, there’s more to manure than just money. You’re going to see many benefits apart from healthy and potent buds. 

Here are four more reasons why you should use manure to cannabis, or any plant for that matter. 

  • Manure Improves Soil Structure

Mulching your soil with manure creates a protective layer over the soil surface, which keeps the natural soil structure intact. Mulching reduces the chances of erosion or soil damage due to external environmental impacts like rain or insects.

  • It is Natural and Eco-friendly

Every farmer wants to improve their yield, so many large-scale commercial growers use chemical fertilizers. But these fertilizers contain toxic petroleum chemicals that harm the plant, environment, and people around.

Instead, if you go the organic way and use manure, you can improve your plant’s health without causing any damage to the plant or yourself. 

Using chemical nutrients excessively can also ward off friendly pollinators like bees and butterflies. Of course, you don’t want your female cannabis plants growing outdoors to be pollinated, but it’s generally a bad idea to use fertilizers that discourage pollinators. 

  • It is a Complete Fertiliser

Manure is loaded with micronutrients and macronutrients, including nitrogen, potassium, and phosphorus. These nutrients, or NPK, are what you see on the labels of your fertilizers. 

If you use chemical nutrients, you will need to combine all macro and micronutrients to provide everything the plant needs. However, you don’t have to mix and match fertilizers or compromise your plant’s mineral supply with manure.

For manure to work, keep in mind that you must always use well-rotted manure. Fresh manure is harmful and full of bacteria. On the other hand, manure is beneficial and serves as a complete package of nutrients only if you use old manure that has been composted. 

  • It Feeds Microbes

Most inorganic methods rely on feeding the plant with nutrients. Conversely, organic methods are all about feeding the microbes or the soil that feeds the plants. If you keep the microbes in the soil happy, they will take care of plant nutrition and do all the hard work for you. 

The organic carbon present in manure serves as the energy source for soil microbes, which has a knock-on effect on your plant’s health. The microbes form a symbiotic relationship with the cannabis roots and pass on the nutrients from the manure to the roots more efficiently. 

Using Manure the Right Way

Planting cannabis in manure

There are primarily three ways of using manure for cannabis:

  • Mix manure into the soil
  • Mulch the soil 
  • Spray plants with manure tea. 

No matter how you use it, remember to use composted or aged manure. 

We recommend mulching the manure because tilling can disrupt the sub-soil life. On the other hand, mulching allows earthworms to drag it towards the sub-soil to break it down without disturbing the sub-soil environment.

However, this process can take quite a long time. If you’re growing autoflowers or even photoperiod plants that grow quickly, you may not have the time to wait. 

In such cases, making manure tea is the best option. 

Making manure tea is an easy yet effective method to ensure the plants get nutrition quickly. Like compost tea, manure tea makes an ideal fertilizer. All the nutrients in the manure dissolve in the water. Next, you can spray the plants with manure water and also use leftover manure to make compost. 

Manure tea could be potent, depending on the type of manure you use, so make sure you dilute the tea with water to prevent the leaves or roots from getting burnt. 

Here’s how you can make manure tea at home:

Manure tea is very similar to compost tea, so you can use the same ratio of water and manure. Generally, it’s best to go with 1:5 parts manure: water to make an effective tea. 

To start, line a 5-gallon bucket with a cheesecloth or burlap sack or even a pillowcase to strain the water. Next, take a shovel filled with manure, place it in the sack, and tie the top to create a make-shift bag. Finally, fill the bucket with water and suspend the bag in the water. You’ll notice the color of the water change slightly.  

Let the water absorb the contents of the manure for at least a week. Next, remove the bag and discard the waste or mix it in with your compost. You now have manure tea, but it needs to be brewed for a while. Therefore, let it sit in the bucket for a few days and stir it frequently with a wooden stick.

Once the tea is made after a week, you can strain the contents with cheesecloth and discard the leftover or combine it with compost. Finally, it’s time to dilute the tea. Just add five parts water to it. So, for instance, if you have 1 liter of manure tea, add 5 liters of water and spray the plant leaves to encourage the plant to grow faster. 

Manure Quantity

Another essential element of using manure for growing cannabis is the quantity. Using too much can choke the soil and cause nutrient burn in the plants, and using too little can be ineffective.

So, we recommend using 1 part manure to 3 parts soil to kickstart microbial activity in the beginning. Later, you can reduce or increase the ratio, depending on the performance.

Best Manure for Cannabis 

Manure for cannabis plants

There are many kinds of manure, like the various kinds of cannabis buds available at your nearest dispensary. Each of these has its benefits and drawbacks, and you need to choose one that fits your objectives the best. 

Be warned — some of these may stink a lot more than others, but better buds at the end more than makes up for it! 

Let’s take a look at the best manures for cannabis.

1. Chicken Manure

Chicken feces is perhaps one of the most common manure for the cannabis plant because it is naturally high in nitrogen with an average content of 1.5%, sometimes going as high as 2.8%. It’s also quite rich in phosphorus and potassium.

Composting chicken manure takes about six to nine months, making it a viable solution for your next year’s cultivation. Once the manure is ready, apply a thin layer on top of the soil.

Chicken manure is also pretty light and easy to get a hold of, so transporting it to your cannabis grow room won’t be an issue.

2. Rabbit Manure

Chicken manure needs to be composted, but if you don’t want to go through the hassle, you can go for rabbit manure as it is also quite rich in nutrients. You can apply rabbit manure directly to your soil or till it. However, always maintain manure to soil ratio of 20% to prevent nutrient burn.

Rabbit manure contains an adequate amount of nitrogen, phosphorous, and potassium, along with calcium, zinc, and magnesium. 

Oh, and the best part? Rabbit manure is almost odorless!

3. Horse/ Cow Manure

Cow manure drying

Horse and cow manure aren’t so different from one another — both are equally beneficial for cannabis plants. They contain 0.7% nitrogen and 0.5% to 0.8% potassium.

However, they may contain unwanted seeds and harmful pathogens, so we recommend composting horse or cow manure before applying it to your plant’s soil.

Also, horse and cow manure may be expensive to transport, so you might want to skip these if you are tight on budget. 

4. Pig Manure

Pig manure is widespread among farmers and, thus, it is readily available almost everywhere. It is not as rich in nitrogen as other types of manure but has enough phosphorus to make up for it. Phosphorus, after all, is essential for cell development.

Also, we recommend always hot composting pig manure before applying it to the soil as it can contain harmful bacteria.

Summary: Can You Use Manure to Grow Cannabis?

Some cannabis growers don’t like using manure or fertilizers, as some studies show plants can accumulate antibiotics from these fertilizers. However, organic manure does not contain any, and if composted well, it is harmless for your cannabis plant.

However, always make sure you buy from reputed suppliers to prevent aminopyralid — a herbicide that often shows up in manure and can destroy crops.  

Other than that, manure is a terrific (and eco-friendly) way to grow healthy cannabis plants with flowers that don’t disappoint.



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