Best Grow Medium for Autoflower

Choosing the right grow medium is essential to growing a healthy cannabis crop with big yields of quality flower. Grow medium simply means the material you are putting in your pots to grow your cannabis in. Soil is the most commonly used grow medium for plants. However it’s not the only grow medium, and certainly not always the best option if you’re trying to grow cannabis.

While there are many types of growing mediums you can use, you will produce the best results with soilless mediums like Coco Coir and Perlite. This is because these growing mediums allow you to feed nutrient solutions directly to your plant’s roots, while avoiding potential bug infestations that you may experience with soil.

Below we’ll go through the different types of growing medium you can use, and teach you how to maximize your yield and the quality of your bud. 

What are the different types of growing medium?

There are two main categories of growing mediums: soil and non-soil.

If you do choose to grow your plant in soil, you will get to decide between soil containing pre-added nutrients, or plain soil without any added nutrients. Since it’s important not to overfeed your plants nutrients, you must be cognizant of whether or not your soil comes with pre-added nutrients, and adjust your plant’s feeding plan accordingly.

There are a number of different growing mediums you can use besides soil. Perlite and Coco Coir are two other popular growing mediums, which are increasingly popular among cannabis growers—and with good reason. Keep reading to learn about the different kinds of non-soil mediums and why they’re so effective. 

Non-Soil growing medium

Non-soil mediums include Coco Coir, Perlite, Peat Moss, Vermiculite, and Rockwool. Coco Coir and Perlite are among the most effective growing mediums you can choose, and beginners are recommended to grow in a coco-based growing medium, with some perlite mixed in.

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The reason these soilless mediums are so effective is that you’re feeding nutrients to your plant’s roots directly through water (hydroponically) rather than pouring water into your soil, which acts as a kind of middle-step before your plant’s roots absorb the water.  Soilless mediums also help to prevent overwatering, and bug infestations.

Why non-soil growing mediums are best for auto-flower: 

Heavy soils will stress out your auto-flowering plants, suffocating their roots and hindering your yield. It’s recommended that you use one of the above soilless mediums, or make your own growing medium using the following method. 

Make your own growing medium: 

All you need to make an ideal growing medium for your auto-flower plant is peat moss, household compost, perlite, and vermiculite. Mix together three-parts peat moss, three parts compost, two-parts wet perlite, and one-part wet vermiculite in your pot and you’re ready to grow. 


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How to keep your soil pH at the ideal levels for your autoflower:

pH level refers to how acidic or alkaline your growing medium is on a scale from 0 to 14. If the number on your pH reader is close to 14, that means you have a lot of alkaline in your growing medium. The closest your pH reader is to 0 the more acidic the growing medium is. 7 is neutral. 

Autoflowering cannabis prefers pH levels that are more on the acidic side. Keep your pH levels in between 6.2 and 6.5 to create the ideal growing conditions for your plant. You can find products to regulate your soil’s pH levels at your local gardening store, or online. 

Test your growing medium’s pH level with this tester kit. 

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Soil with Microorganisms:

If you choose to grow your autoflower plant in soil, you will have to worry about potential pests that will come and eat your cannabis plant from the outside in to the detriment of your plant’s leaves, flower, roots and stems. 

An interesting way to combat these unwanted pests is to unleash an army of predatory microorganisms that will eat any harmful pests that may be active in your soil. However, this may result in the unsavoury discovery of little bugs in your cannabis flower down the line, which recently happened in Canada as the province of Ontario attempted to roll out some of its first government sanctioned legal cannabis. Cannabis flower purchased from one company in particular, RedeCan, was particularly full of these little bugs, which a spokesperson later said were predatory mites to prevent outbreaks of spider mites, which kill cannabis crops.

These bugs are harmless to consumers, and as RedeCan pointed out, using these predatory mites means they don’t have to use chemical pesticides. In other words, these mites are an organic alternative to chemical pest control methods that are often illegal and harmful to consumers’ health. Still, nobody likes finding bugs in their weed. 

Want a second opinion on the best growing medium to use? Check out this great video by dubxxl!

Want to know the best nutrients to buy for your vegging plant? Read our comprehensive guide!



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