Perlite vs Vermiculite: Choosing the Perfect Weed Growing Medium

If you are a cannabis grower, one of the important decisions that you have to make is which growing medium should best suit your garden. Known to be a very versatile plant, cannabis can be grown in different growing environments via different growing mediums.

Among the popular mediums that growers use to grow are perlite and vermiculate. At a glance, these two may look similar but knowing the difference between perlite vs vermiculite will allow you to decide which among the two is the perfect additive for your plants.

Read this article if you are interested in the similarities and the differences between perlite vs vermiculite so you may decide later on which among the two is the one you need for your cannabis garden.

What is cannabis grow medium?

A cannabis growing medium or growth medium is whatever you use to anchor your cannabis plant, it is where the cannabis plant is placed to develop its root system. There are different mediums that you can use in growing your cannabis plant. The most common medium is soil but some farmers also use coco, coir, water, Rockwool, perlite, and vermiculate among others.

It is crucial to choose the right medium for your cannabis plants. The medium will also depend on the grow space that is intended for your cannabis cultivation. Aside from soil, cannabis cultivators are also using vermiculite and perlite as an effective way of growing cannabis.

Perlite vs Vermiculite: Which is an Ideal Medium

As mentioned, different growing mediums can be used in growing cannabis. There are two particular mediums though that are popular among cannabis cultivators and these are perlite and vermiculate.

Perlite and vermiculite are used by cannabis cultivators to improve the soil’s moisture retention as well as allow a good passage for the air to flow. They may have the same functions but they are interchangeable. They also have distinct differences. Choosing between the two depends on what your plant needs.

Before you decide to use these two mediums, it is best to know the similarities and differences between perlite vs vermiculite.

What is Perlite?              

Perlite is a growing medium that is made from volcanic rocks. These volcanic rocks have been heated and crushed until they turn into small white pieces. Perlite is added to soil to improve the soil’s drainage system. It can retain water just enough but it has low nutrient retention. When added to the soil, it improves the drainage capability of soilless and soil-based potting mixes.

It insulates the roots of the plant from extreme heat or temperature change. It also serves as a protective coating on the plant’s pelleted seeds. This medium is clean, odorless, easy to handle, and lightweight. Perlite’s pH ranges from 6.6 to 7.5.

Here are the different characteristics of Perlite:

  • It is ideal for seed starting mixes when you try to blend your soil mix
  • It losses and lightens solid that are heavy and compact
  • It can hold nutrients three to four times its weight in water
  • It is odorless and clean
  • It is non-toxic
  • It has a neutral pH level
  • It won’t cause any mold or rot in the plant
  • The pieces contain 6 percent water
  • It is lightweight
  • It floats on top of potted plants

Given its characteristics above, perlite is usually added to containers and is also used in a hydroponics system.

What is Vermiculate?

Vermiculate is a natural mineral and converted as a soil additive that helps increase nutrient and water retention. This medium has very high water and nutrient retention. When added to the soil, it can help as an anti-caking agent whenever you are using fertilizers that can mess up with the soil’s drainage or airflow.

Vermiculite is safe to use as it does not contain any toxic materials. It is safe for both commercial and personal use. It is best to use vermiculite in plans who are water-loving or those who need to stay moist at all times.

Here are the different characteristics of Vermiculite:

  • It retains moisture and provides nutrients to the plants
  • It is ideal for seed starting
  • It is ideal if you are blending your soil mix
  • It lightens and loosens heavy and compact soil
  • It is an ideal mix for soil as it mixes very fast
  • It is non-toxic and it can be used personally and commercially
  • It is sterile, clean, and odorless

Perlite vs Vermiculite: Similarities 

Both perlite and vermiculite are mediums that are used as an ingredient soilless potting mixes. This soil mix is used in growing cannabis plants during seed germination, hydroponic containers, propagation as well as transplants. They are used as carriers in pesticides, dry fertilizers, and herbicides and help the plants absorb them.

They can both improve the soil’s drainage system, increase moisture retention, and prevent compacted soil. They are very helpful in propagating new plants and are ideally used in seed starting. They are both non-toxic and sterile and inorganic and they can improve the soil’s aeration.

Perlite vs Vermiculite: Differences

The main difference between the two is on water and nutrient retention. Perlite has low water and nutrient retention while Vermiculite has very good or high water and nutrient retention. Perlite dries out quickly while it takes some time for vermiculite to dry out. This is the reason why vermiculite is best for plants who need water all the time.

Use perlite if you are growing cannabis strains that need to dry up before you water them again and when you are moving seedlings and place them on separate pots. You may use vermiculite in plants that need water or moisture most of the time. This additive keeps seeds stay strong as they are developing.


Both perlite and vermiculite are helpful media in growing your cannabis plant. Knowing the difference between perlite vs vermiculite is essential so that you will know how, when, and what you are using them for. If you aim to grow a healthy cannabis plant and produce quality yield, you might need the aid of these two mediums as they can improve the quality of your growing environment.

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