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Why Do Some Cannabis Buds Turn Purple?

Everybody loves and knows the beautiful purple color some cannabis plants can exhibit, but do you know why they do it?
04 April 2022
7 min read
Why Do Some Cannabis Buds Turn Purple?

  • 1. What are anthocyanins?
  • 2. How do anthocyanins work?
  • 3. Benefits of athocyanin
  • 4. What parts of a cannabis plant can turn purple?
  • 5. Purple genetics
  • 6. Our purple strains
  • 7. In conclusion

Before breeding became popular, the only way to get purple buds was by growing cannabis in cold temperatures but nowadays you can find purple strains that develop not only purple but pink, red, and blue hues without doing anything special.

Modern plants have been selected to have an increased Anthyocianins production, which makes them show unique colors without doing anything special during their growth.


Learn why some buds turn purple with Sebastian Good.

1. What are Anthocyanins?

Anthocyanins are water-soluble pigments classified as flavonoids whose primary function is to protect the surface of the buds against UV rays.


Why do cannabis turns purple?: where it can be found

Anthocyanins aren't exclusive to cannabis and can be found widely in several fruits, vegetables and plants.

This compound usually manifests as purple but can display a variety of different colors such as blue, red, pink, and black depending on the pH level throughout your plant’s life cycle and can be found not only on cannabis but also on several fruits, plants, and vegetables such as grapes, cabbage, and eggplants. 

Also, because it is a flavonoid, it is said to play a role in the effect a cannabis plant can have, just like terpenes do.

2. How do anthocyanins work?

Anthocyanins are not produced at all times, when a certain strain has been selected to change colors, it will stop producing chlorophyll in the last weeks of the flowering stage which will allow the pigments to show even more.


Why do cannabis turns purple?: how do they work

Even though purple is the most common color, some plants can display black, pink or reddish hues.

Normally, cannabis plants are green because they use chlorophyll to absorb light but in its absence, they can use anthocyanins in its place and will absorb all wavelengths of the lights spectrum, except the blue (or indigo) spectrum and because it’s the dominant pigment, your plant will turn purple.

3. Benefits of athocyanin

Recent studies showed that these compounds have an affinity with cannabinoid receptors, anthocyanins are known to be antioxidants and have analgesic, anti-inflammatory, and neuroprotective properties, although there are ongoing studies so it’s too early to confirm if anthocyanins really bring benefits.


Why do cannabis turns purple?: benefits

Despite not being scientifically confirmed yet, anthocyanins can bring several benefits to humans.

Lots of people claim that consuming foods with this compound can increase longevity, prevent dementia and cancer so even though it's not confirmed, you can have an idea of the benefits.

4. What parts of a cannabis plant can turn purple?

Depending on the amount of anthocyanins and where they’re located, your whole plant can turn purple this is not very common, although possible.


Why do cannabis turns purple?: purple parts

Depending on the strain, you will see different parts of your plant changing colors.

Normally you will see certain parts of your cannabis plant changing color and not the whole plant.


Part of the plantImportanceColors
PistilsWhite hairs you see on female plants, responsible for catching pollen.Usually orange but can turn pink or purple.
CalyxesSeed pods that make up the buds, also protect the seeds.Can exhibit black, purple, pink, blue, and red hues.
LeavesPerform photosynthesis for plant growth (aka fan leaves). Can display red, pink, purple, blue, and even black tones.
TrichomesTrichomes produce and store cannabinoids and terpenes.Usually white but sometimes can turn black or purple.


All of these parts of a cannabis plant can turn purple and it usually depends on the genetics and the environment they’re grown in, even though the genetics have been specially selected, you should also try to provide the best environment to encourage your cannabis plants to exhibit the unusual colors.

5. Purple genetics

The best way to end up with beautiful purple (or black, pink, etc..) buds is to start with the right genetics, nowadays most seedbanks offer colorful strains that don’t depend on anything other than proper care to end up turning purple.


Why do cannabis turns purple?: genetics

Beautiful purple buds with bright orange pistils.

Have in mind that most plants contain anthocyanins but won’t exhibit different colors due to the low amount and when growing purple genetics, you won’t see a difference until the last couple of weeks before harvesting when flushing the nutrients off your plant.

All of these strains have been specially selected and bred for their unique colors, this happens because breeders select the plants that have a tendency to produce higher levels of anthocyanins, but this doesn’t mean that they will turn purple on 100% of the cases. 


Why do cannabis turns purple?: genetics

Strains that haven't been selected for unique colors can still display them if grown under certain conditions.

Even though a certain strain can be purple, they may still need certain conditions to exhibit other colors, although it will be way easier to achieve it than with other genetics, those factors include:

  • Temperature
  • Humidity
  • Genetics
  • pH level
  • Nutrient amount

To encourage your plant to display unique colors, you should provide lower temperatures because cold causes chlorophyll to break down and can influence your plant into producing more anthocyanins, ideally, there should be a difference of about 10-15°C between daytime and nighttime temperatures for this to happen but it can depend from strain to strain. Also, providing these big changes in temperature can also help non-purple strains to change colors, although it won’t work with all plants.

Keep in mind that if you do decide to lower the temps to try to coax out some extra color changes, it's best to make these reductions slowly. If you, all of a sudden, drop the temps by 10 to 15°C you may cause some serious shock to the plant. You also increase the likelihood of the plant developing mold issues, especially if the humidity levels are not strictly monitored. Try it if you are feeling adventurous, but remember to keep a close eye on the ladies to make sure they don't freak out.

Is it true that purple weed is more potent than regular bud?  

Thanks to popular culture and the worldwide rumor mill, there is a long-standing belief that purple buds are stronger than your everyday weed. But how true is this?  Well, in terms of concrete scientific proof - there really is none at all. That's not to say the anthocyanins that turn the weed purple play no role at all in how the high feels, but there is zero evidence pointing towards purple sticky-icky providing a stronger or longer-lasting high. With the recent changes concerning cannabis law, we are thankfully seeing our favorite plant being put through rigorous scientific studies at a much higher rate than ever before. What we can say for certain is that anthocyanins are mostly processed by the digestive system, so there may be some benefits when consuming purple weed in edible form.


A different, and maybe more important question we can ask is “is purple weed better?" That really comes down to personal preference. For some of us weed enthusiasts, the satisfaction we seek is as much about the look and smell of a certain bud as it is the cerebral effects. It's not always about how strong the weed is, or how long the high will last. There's a certain beauty in purple weed varieties that you simply don't find elsewhere.

There is also a strong connection between purple weed and popular culture, in particular hip-hop and rap but also with classic stoner films from the 2000s. This connection can provide smokers with some feelings of nostalgia that you don't get from other strains, and may also mean that the myth of purple dank may never totally disappear, even if firm scientific evidence arises showing it has no true difference from regular old green and orange bud. And don't forget the bag appeal! Is there anything better than scoring a big bag of sticky, stinky, gorgeous purple flowers that make you feel fantastic? We think not.

6. Our purple strains

If you’re looking for purple genetics to grow in your next grow cycle, don’t look further, we have several purple strains that have been genetically selected to exhibit unique colors without the need to do anything extra, such as our Blackberry Auto.

Tight buds with an intense purple color with a very characteristic smell, with lemon or forest fruits. - Thejusepas

Now, if you're looking for something with a strong cerebral effect, we recommend our LSD-25 Auto.

This beautiful purple hybrid will develop dark orange pistils on mostly dark purple buds, exhibiting sometimes light purple hues with stunning yellow, and reddish-pink colors on the leaves at the end of the flowering stage and especially after properly flushing

LSD25 Auto
5 out of 5
Top notch strain. Easy to grow and produces prolific flowers. I got 6 ozs. of great medicine from her. I will definitely grow this strain again.
Verified customer
Reviewed 19 February

As you can see in the video below, when the flowers begin to form, the buds will slowly start turning purple and when your plant is ready for harvest, the buds will completely exhibit a dark purple color with sometimes lighter hues throughout them.


Video courtesy of Bengrowerbr from Grow Diaries.

"...LSD-25 produced some of the best looking dark purple cannabis buds I have ever seen." - Freeglocks

This is because our purple varieties have been genetically selected throughout the years to develops anthocyanin-rich autoflowers, so without doing anything extra, you can expect a beautiful purple color when nearing harvest.

7. In conclusion

Growing colorful buds won’t make them more potent but they will certainly have a better appeal and depending on the different hues, will end in flowers that you won’t even want to smoke, just stare at them all day long. If you have grown one of our purple strains before, share your experience with fellow growers, feel free to leave a comment in the comment section below!

External References:

  1. Anthocyanins: From the Field to the Antioxidants in the Body. - Bendokas, Vidmantas & Stanys, Vidmantas & Mazeikiene, Ingrida & Trumbeckaite, Sonata & Baniene, Rasa & Liobikas, Julius. (2020).
  2. Anthocyanins in human health. - Shemet, Sergiy & Eliseeva, Tatiana. (2020).



This post was most recently updated on April 4, 2022.

04 April 2022