How can I grow purple cannabis plants?

That’s one of the most asked questions on our DutchFem Live Chat. In this blog, we will try to explain some things about it! Who doesn’t want to have one of those beautiful purple, pink and/or blue colored cannabis plants? Just because of those colored buds, they already look a lot fruitier and tastier even if the color usually doesn’t affect the taste. For starters, we have to get the biggest misconception out of the way about purple cannabis. Cannabis plants that grow outside usually get dark blue leaves during the end of their flowering period, which makes a lot of growers think that this is a purple strain. This is not the case and happens because of cold nights. A real purple strain doesn’t get purple or blue leaves but purple, pink or blue buds. The leaves stay green, except if these are way too cold in the dark, of course. But in theory, the leaves should stay green.

Purple Haze is obviously the most well-known purple strain but there are many purple hybrids of purple haze available. Blueberry is also a popular blue/purple used widely to make colorful crossings. Almost every grower has made their own purple strain and, of course, we at DutchFem finally made our own purple strains as well. The Purple OG Kush was the first but more are coming soon because of the ever-growing demand for these beautiful Purple strains.

Why do purple cannabis strains become purple?

We get asked this question a lot and will try to explain here what gives a purple strain its color. If you want to speak about a truly purple strain it has to contain enough anthocyanins. These are purple dyes that give the plant its purple tint in the last phase of the flowering period. The more anthocyanins a strain contains the more purple it will turn out.

There’s a variety of things you can do to stimulate the coloring of your weed. Anthocyanins are obviously not just there to give your plants a nice color but also provides protection against (too) intense light. That’s why you see a lot of buds that are too close under the light will become purple faster than the buds further away from the light source. You can experiment by lowering your light source a little in the last phase of flowering as long as there’s still hot air between the lamp and the plants but enough will be blown away by fans and/or extractor. Obviously, you don’t want your tops to burn.

Are there other options to make Purple cannabis?

What also usually works is lowering the temperature during the dark night to just about 10-12c. This doesn’t just stimulate THC production. But it will help your plants get that blue-purple color. It’s important that the temperature during the light period is 24c-26c, otherwise, the plant won’t flower as much which can have negative consequences to the yield.

Lastly, you can influence the color of your plants by increasing the acidity of your soil. On more acidic soil plants will turn purple or blue more often than on neutral soil. You can easily do this by changing the PH value of your water from 6.3 to 5.8 during flowering, and even to 5.2 in the last week. This way the PH value of your soil will go down as well and you will stimulate the coloring. Do pay attention that you don’t give any more nutrients and that the EC value doesn’t exceed 1.0 or your roots will burn