Why Do Some Cannabis Plants Turn Purple?

Purple weed is royalty and luxury combined. Some of the most exotic weed strains have a purple hue; Granddaddy Purple, Purple Haze, and Purple Kush. There is no doubt that purple cannabis is a cut above the rest and consequently one should expect to pay a premium price for this.

That said, there are a lot of grays when it comes to understanding why some weed turns purple and whether purple weed offers extra benefits. In this short article, we explain the science behind purple weed and why you should try one, in case you haven’t already. Of course, there are myths, and we will deal with that as well.

What is Purple Cannabis?

Just as the name suggests, purple cannabis is cannabis that has purple hues. Typically, cannabis nugs are predominantly green in color, due to the presence of chlorophyll. As the plants mature the nugs are coated with a milk-white layer of trichomes. Under a microscope, the trichomes appear like snowflakes.

Some strains of cannabis will develop purple coloration during the flowering stage. This is due to the presence of a chemical compound that is known as anthocyanin, you will learn more about this pigment later on in the article.

Purple strains of cannabis include:

  •          Granddaddy Purple
  •          Purple Kush
  •          Purple Urkle
  •          Purple Haze
  •          Grape Ape

The Science Behind Cannabis Plants Turning Purple

Two factors are needed to induce purpling in cannabis; high anthocyanin levels and cool temperatures during the flowering stage. This is how it all happens.

During the vegetative stage of cannabis, chlorophyll (green pigment) is dominant and facilitates photosynthesis. Once this stage is over and the plant moves to the flowering stage the chlorophyll is broken down and creates room for the expression of other pigments such as anthocyanin. Once the anthocyanin takes over, the plant turns purple.

Some cannabis strains are genetically predisposed to have higher amounts of anthocyanin. These are the strains that will eventually turn purple during the flowering stage when temperatures are lower. Without this predisposition, it is not possible to induce purpling in a cannabis strain.

Other plants that have high amounts of anthocyanin include:

  •          Blueberry
  •          Cranberry
  •         Blackcurrant
  •         Eggplant
  •          Black rice
  •          Ube
  •          Red cabbage
  •          Okinawan sweet potato

About The Purple Cannabis Leaf

When a cannabis leaf turns purple during the flowering stage it signifies high amounts of anthocyanin. However, this can also signify phosphorous deficiency. Plants that lack phosphorus will lose their vibrancy and begin to die. Older leaves and stems will then develop a purplish color. It is interesting to note that phosphorous deficiency triggers anthocyanin synthesis. Offering phosphorus to the plant may help to reverse this situation.

Color Chart of Cannabis Leaves

Flavonoids are responsible for the different colors in cannabis. These hues are important for photosynthesis; they also protect the plant from harmful UV rays. Purple is not the only exotic pigment that is present in cannabis. Other pigments include the following:

Chlorophyll: It represents about 70% of all the pigments in most plants. It is essential for the health of plants because it allows leaves to absorb light for photosynthesis. Chlorophyll masks other pigments, this explains why most plants are predominantly green.

Carotenoids: These feature orange, yellow, and red hues. For example, lycopene is an example of a carotenoid that has red pigments.  Carotenoids are important for the production of vitamin A. As the chlorophyll content of plants diminishes during fall, the true potential of carotenoids is manifested.

Myths About Purple Cannabis

Several myths have been put forth to try and explain why some cannabis turns purple. Here are a few that are important to debunk

Myth 1: Depriving cannabis of nutrients will cause it to turn purple

If you deprive cannabis of nutrients such as oxygen, carbon dioxide, or minerals, the plants will begin to die. As mentioned above, withholding phosphorus will cause the old leaves and stems to turn purple. However, you will soon be on your way to losing your crop. Therefore, this is not an effective way to create purple cannabis.

Myth2: Freezing cannabis will cause it to turn purple

Cannabis strains that have high amounts of anthocyanin will require cooler temperatures during the flowering stage to allow the purple pigment to dominate. However, this does not apply to all cannabis strains, and subjecting some to winter conditions will not give you what you are looking for.

Myth 3: Food Color can do the trick

Forget it, you cannot create purple weeds by adding food color to the water that you give to the plants. If you want to end up with purple weed it is advisable to start with the right genetics; strains with high anthocyanin content.

Are There Any Benefits to Purple Weed?

Purple weed is not superior to green weed in terms of therapeutic value. The therapeutic potential is based on the concentration of cannabinoids and terpenes and not so much on flavonoids. That said, anthocyanin has several benefits that include the following:

  •          Anti-inflammatory
  •         Anticancer
  •          Antidiabetic
  •          Antimicrobial
  •          Anti-obesity

Are Purple Leaves Genetically High?

Many people believe that purple leaves have stronger potency than the rest, but this is hardly the case. The potency of purple weed will vary based on the concentration of THC in each strain.

FAQ: Why Do Some Cannabis Plants Turn Purple?

Q1. What causes cannabis plants to turn purple?

A1. Cannabis plants can turn purple due to a combination of genetics and environmental factors such as cold temperatures and low light. The anthocyanin pigments in the plant are responsible for the purple pigmentation.

Q2. Are purple cannabis plants more potent?

A2. Purple cannabis plants are not necessarily more potent than green plants, but they may have a higher concentration of terpenes, which can give the plant a stronger flavor and aroma.

Q3. Are purple cannabis plants more expensive?

A3. Purple cannabis plants may be more expensive due to their rarity. Since they are not as common as green plants, they may be harder to find and therefore more expensive.

Q4. Are purple cannabis plants more difficult to grow?

A4. Purple cannabis plants are not more difficult to grow than green plants. They require the same care and attention as any other cannabis plant. However, they may need to be grown in specific conditions to maintain their purple color.

Photo of author

Lydia K.

Lydia K. (Bsc. RN) is a cannabis writer, which, considering where you’re reading this, makes perfect sense. Currently, she is a regular writer for Mace Media. In the past, she has written for MyBud, RX Leaf & Dine Magazine (Canada), CBDShopy (UK), and Cannavalate & Pharmadiol (Australia). She is best known for writing epic news articles and medical pieces. Occasionally, she deviates from news and science and creates humorous articles. And boy doesn't she love that! She equally enjoys ice cream, as should all right-thinking people.

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