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Common Cannabis Mutations

Fasciation & Variegation
By Colin Gordon & Ben Owens

By Colin Gordon & Ben Owens

If you run enough seeds, you’re going to see mutations—something that just doesn’t grow the way it should.

Some are, without question, special and offer an opportunity for unique breeding projects, like the Freakshow variety that became popular in many western markets because of its unique fern-like appearance. Others are simply deformed plants who will at best perform like the rest, and at worst, slow down or cause problems for the crop.

Most mutations are undesirable and cause the plant to underperform.

Two of the most common mutations you'll encounter are Fasciation and Variegation.

Credit: Ascent 420


Fasciation is a plant mutation that can affect any plant—cannabis or not—and expresses through abnormal elongation, flattening, or clustering of stems, leaves, or flowers, causing them to grow in unusual and often distorted shapes.

This condition is often described as appearing like a portion of the plant was flattened or stretched out, with the apex of a cola or branch looks like a fuzzy caterpillar.

Fasciation is often caused by: 

Genetic mutations

Hormonal imbalances


Bacterial or viral infections

Physical damage

Extreme temperatures


Nutrient deficiencies.

Fasciation can occur at any stage, but is most commonly seen during the vegetative and pre-flower phases, affecting a single branch or multiple branches. Affected portions may grow slower than normal, which can impact yield.

While this mutation can result in unique and interesting growth, it often reduces yield and quality.

If you see fasciation on a plant, we recommend removing affected parts to allocate the plant's energy to healthy growth. 

To prevent fasciation: 

  • Maintain a stable growing environment
  • Avoid physically damaging the plant
  • Maintain healthy nutrient levels and avoid over-fertilization

Photo by Multipass Holder: Steve Zalesky


Variegation is a condition where plant material displays irregular patterns of color due to a lack or excess of chlorophyll, resulting in patches or streaks of white, yellow, or other colors.

In houseplants, grown without concern for final yields, variegation is desirable because of its unique appearance and aesthetic value. It’s very common to seek these out in monstera and pothos plants, and, in some cases, variegation is intentionally induced through breeding or tissue culture techniques to increase this value.

In cannabis, variegation usually has little to no impact on the final product’s form from what we have seen unless that expression is super dramatic; In some cases it’s so extreme that it reduces vigor and growth rate.

Variegation is just a mutation that occurs from time to time, and, in some instances, breeding can enhance or diminish its chances of expressing.

Variegation can occur due to: 

Genetic mutations

Stress (Viral infections, extreme temperatures, exposure to toxins or foreign compounds)

It is more likely to occur in plants subject to low temperatures, extremely low or high light intensity, as well as nutrient deficiencies or toxicities.

As a breeder, I haven’t found an upside in breeding with something variegated; I don’t want to create offspring with abnormal chlorophyll levels (chlorophyll affects photosynthesis, which affects resin and biomass production). If anything, a heavily variegated plant is likely less photosynthetic than a non-variegated plant.

If you see variegated leaves in your grow, know that it is generally considered harmless unless it is the result of a viral infection or nutrient deficiency.

To maintain healthy growth and minimize the risk of variegation, it is recommended to maintain consistent growing conditions, avoid exposing plants to extreme temperatures or toxins, and ensure proper nutrient levels are maintained throughout the plant's life cycle.

At the same time, just because a plant looks different, doesn’t necessarily mean the plant is variegated.

Sometimes plants have just a single leaf experiencing local chlorosis and one blade is white; that may not be variegated. There are different types of mutations. Some are predictable and consistent like variegation, others like the mutation seen on the Freakshow leaf are not as common. Stress during any stage of a plant’s life can increase the likelihood of mutations.

Mutations are outliers, and most are not useful.

Sometimes plants just grow weird.

It's like in comic books: they make radiation poisoning seem really cool because you become a superhero, but usually it just makes you sick and lose flesh.

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