The Best Purple Cannabis Strains

The best purple cannabis strains – and let’s add blue cannabis in here too!

The best purple cannabis strains always seem to disappear quickly whenever you grow them: friends pop round more often, and suddenly your stash is gone. So what makes a purple (or blue) strain that color, what’s the best way to grow purple weed – and what makes it unique? Read on and you’ll find out.

What Makes a Purple Cannabis Strain Purple?

All higher plants – those that use a vascular system to distribute nutrients and water up from the roots to the leaves and flowers/fruits – contain a varying level of a flavonoid called “Anthocyanins.”

What are Anthocyanins?

Don’t confuse the term “flavonoid” to mean anything to do with flavor: it actually comes from the Latin word for “yellow”. Flavonoids work as chemical messengers, symbiotic nitrogen fixers, and more.

Anthocyanin is a distinctive flavonoid that acts as a coloring agent in the epidermic layer of plant tissue, turning it red, purple, or blue depending on the pH. It acts as a sunscreen preventing high-light stress and is also the reason some trees have leaves that turn red in autumn.

Allegedly, anthocyanins are thought to be present in all cannabis strains. Still, most are either not exposed to the right environmental conditions to produce them, or they do so in such low quantities that it doesn’t make a visual difference.

How to Grow The Best Purple Cannabis Strains?

best purple cannabis strains

Towards the end of flowering, plants receive the signal to stop producing chlorophyll so that all energy goes towards bud production.

Simultaneously, anthocyanin levels increase, and as the plant’s leaves fade from lack of chlorophyll, they take on a reddish/purple/blue tinge produced by the higher levels of the flavonoid. The anthocyanin travels throughout the vascular cells, even into the trichomes, staining them with that beautiful color.

Traditionally you needed to have a cold last few weeks of flowering to trigger any latent “blue gene” and bring out the distinctive coloring. The popularity of these blue/purple cannabis strains has encouraged breeders to breed in anthocyanins dominance selectively, and it’s now possible to achieve that attractive bud in normal conditions.

How to Boost Color in the Best Purple Cannabis Strains?

To maximize the quantity of anthocyanin and really grow some deep-blue bud, you need to drop nighttime temperatures to simulate cool mountain evenings in autumn (most blue/purple strains will have some Kush in them). To sum up:

  1. Use a long flush period – up to 3 weeks – to encourage the plant to break down all chlorophyll and give the anthocyanin time to permeate the plant and bud
  2. Increase anthocyanin levels with low nighttime temps
  3. A slow curing process in the fridge may ensure that the purple color “fixes,” but DO be careful of bud rot and mold using this method.
  4. There are specific additives that are supposed to encourage the purpling effect.

Some of The Best Purple Cannabis Strains

The Purps

From BC Bud Depot

Even though is not the biggest yielder, The Purps is a connoisseur’s strain, grown for its deliciously grapelike flavor and intense high.

Granddaddy Purple

At one point, THE smoke to have. Grandaddy Purple is a cross between Purple Erkle and Big Bud, so it benefits from high production as well as the fruity smoke and intense indica effect.

This is not available in seed form, only as a cutting.


From the former TGA Subcool (now The Dank Subcool).

An indica dominant hybrid featured with an amazing flavor that outruns the slow Urkle mom.

Original Flo

From Dutch Passion.

Thai/Afghani/Mexican genetics with a 50:50 Indica/Sativa ratio


From Soma Seeds.

One of the all-time-best mellow, violet-colored, indica-dominant strains available to the public. Produces a relaxing and soothing high.

Purple No. 1

From Dutch Passion.

A giggly sweet high with deep purple tones

Dark Devil Auto

From Sweet Seeds.

A  visually stunning autoflowering purple strain.

Grape OG

From Cali Connection.

A sweet and sour sativa/indica mix with incredibly potent high.

Purple Haze - The Best Purple Cannabis Strain

From Sensi Seeds.

Praised by many, of course, Purple Haze had to make this list with its soaring Haze high.

Our Personal Favorite Blue Cannabis Strains

Blue Dream

Available from MNSL and Humboldt Seeds Organization.

Originally a clone-only. It was the best selling strain in Colorado in 2015, with high medicinal value and consistently excellent reviews, and it remains popular among blue strain lovers.


From Dutch Passion.

With blue tones and a truly blueberry taste, this is an easy to grow plant that’s ideal for novice growers.

Blue Cheese

From Big Buddha Seeds.

It captures the essence of the Cheese variety perfectly.

Mataro Blue

From Kannabia Seeds.

A highly valued strain for its medicinal and therapeutic effects.

Benefits of the Purple Weed

So, what makes purple or blue weed special?

Honestly, as far as science is concerned: nothing. However, there have been several experiments recently discussing how the presentation of the food affects our interpretation of its taste and quality.

And this certainly goes beyond new-age gibberish. For example, when you’re down with a cold and a stuffy nose, food doesn’t taste the same, all because you can’t smell it. Or you eat a yellow yogurt, and you taste banana (and only God knows what’s really in those). This is because all five senses are connected and affect each other.

So that’s probably what happens with these purple/blue buds. They look so gorgeous we lead ourselves to believe they have some mystical effects. Also, we’ve heard so rave reviews about a few (mainly clone-only) legend strains such as Blue Dream or Grandaddy, that we convince ourselves any other purple or blue bud has to be special.

On the other hand, science has been researching the role anthocyanin plays in our overall health, with anti-oxidant, anti-inflammatory, and more benefits. This suggests that the high levels of anthocyanin in purple/blue weed might have secondary medicinal effects. So far, it leans more to the speculation side, but maybe the high levels of anthocyanin combined with cannabinoids can enhance the overall effects of the plant.