grow purple weed

Wondering how to grow purple weed? Check it out!

If you enjoy growing cannabis, you might be tempted to grow a fantastic purple weed plant, whether to impress your friends or as an experiment. Read our essential guide to growing purple marijuana!

For some cannabis growers, growing beautiful purple marijuana is simply an enjoyable thing to do but its appearance matters less than the flavour. However, sometimes it’s nice to try something new or take on a challenge. People often grow purple weed to show their breeding skills to their marijuana friends, and some believe the colour positively affects the quality of the cannabis. Weed with an appealing colour never fails to attract attention in your grow room.

Want to know how to grow purple weed and which steps to take? Keep on reading!

Is purple weed better than green?

The short answer is ‘no’. If a seller of purple weed claims it’s more powerful and better than normal cannabis, he or she is either lying or doesn’t know much about growing cannabis. The next time you pop into a coffee shop, pay close attention when asking why purple marijuana is so much more expensive. In reality, it is sometimes significantly weaker than the same strain in green.

Why plants are usually green?

Most plants use a pigment called chlorophyll to convert light into energy for growth. However, there isn’t a specific destination for a green wavelength in the light spectrum. Chlorophyll appears green because it is able to absorb all colours but happens to reflect green, which is the reason why most vegetation is green.

However, you might be surprised to learn that green chlorophyll is not the sole pigment that plants use to make energy from sunlight. There is an additional pigment, known as anthocyanin, which is a purple pigment.

Why is some weed purple?

The interesting thing is that the purple section of the light spectrum contains the most energy. When your plant is purple for whatever reason it reflects this high-energy light instead of utilising it. This means that the plant does not use the light fully and optimally. It also means that your cannabis plant will not grow to its maximum potential. As a result, it may ultimately be less powerful than a green variety.

Some types of purple cannabis are stronger than others

Not all purple cannabis strains are weaker than green ones. Some species that grow purple flowers, such as Granddaddy Purple or Pinkman Goo, are grown to contain a lot of cannabinoids. This makes them incredibly powerful, despite their hue. In other words, potency depends on genetics.

Ways to cultivate a purple weed plant

There are two ways of growing purple weed. You can choose a special species, such as Purple Kush, which turns purple by itself or you can let normal weed, which is usually green, turn purple. We’ll explain how you can turn regular cannabis strains into purple cannabis.

How to prepare your purple cannabis?

If you are keen to grow purple plants, you don’t have to do anything special at the start. Simply start with seeds or cuttings in the usual way. Put the seeds in a seed pot or in the pot in which you want to leave them. Allow your plants to germinate and grow as usual. The purple colour comes later when your cannabis plants start to flower.

When your plants are mature and show the first signs of flowering, you can start the process that will turn them into purple beauties. The main thing is to perform a simple but effective action: lowering the night temperature for your flowering plants. Cannabis plants turn purple when they experience chilly nights! As a rule, your plants turn purple if the difference between the day and night temperatures is around 15 ° C or more. However, make sure that the temperature is not too low because that will hinder the maturing process.

The mechanism that causes your cannabis plants to turn purple is the same that causes the trees to change colour in the autumn. Another explanation is that the lower temperatures cause the plants to produce less chlorophyll. However, they produce more purple (or red or brownish) anthocyanins.

It may not always be possible to lower the night temperature for your plants in such a way that they turn purple. Growers often start growing outside late in the spring and continue in the summer when the nights are never cold enough to make the plants turn purple. They are ready for harvesting at the beginning of autumn before the nights get cold.

If you grow indoors in a tent, it is possible to grow strains in the autumn photoperiod. You will then be able to control the vegetative and flowering phase of your plants by changing the light cycle. If you plan the grow schedule, then the night temperatures will hopefully be low enough to colour your cannabis purple. If it doesn’t get sufficiently cold in your grow room at night, you could try and lower the temperature with air conditioning. But what should you do if you want to grow purple weed plants in the open air?

Tips for a magnificent purple harvest grown outside

It is not possible to start outside with a photoperiod type when it is autumn or winter. This is mainly because there are fewer hours of daylight which confuses the growth phase of your plants rather than the lower temperatures.

Choose to grow your plants indoors and put them outside when they have reached a good height. They should bloom at the end of autumn or the beginning of winter when the days are shorter. This is assuming that it is not too cold and that it is not going to freeze. If there is a cold spell, bring your plants indoors quickly!

Autoflowers for beautiful purple ‘winter weed’

In some climates, such as southern Europe, it is possible to grow outside in the winter. The temperatures are pleasantly warm in the daytime and, while the nights are a bit chilly, there is no risk of frost. The perfect conditions for growing purple marijuana!

If you want to grow a nice stock of beautiful purple buds outside, choose autoflowering strains. Autoflowers are perfect for autumn, winter, and the early spring. The amount of daylight is then too little for growing and flowering photoperiod cannabis plants. Autoflowers can be planted ‘in-between seasons’ so that you can harvest beautiful crops of purple winter weed. At the end of spring, you can then grow the photoperiod of cannabis strains.

Whether you grow strains that turn purple by themselves or transform normal cannabis plants into purple beauties; growing purple marijuana is very interesting and enjoyable. Use this guide to show off your horticultural skills and amaze your friends with your beautiful purple tops!

Want to grow a purple weed plant? In this blog we tell you how to grow purple weed indoors or outdoors! Check it out!

How to Grow Purple Cannabis

Every grower has fantasised about harvesting big, purple buds at home. But what exactly can you do to manipulate the colour of your weed?

Purple cannabis certainly does exist, but there’s a right way to turn your pot purple, and a wrong way.



Purple weed is real eye candy. And while there are many rumours circulating the internet about how to grow purple cannabis at home, there are really only two variables that you can play with to manipulate the colour of your weed. Keep reading to find out what they are.


All plants have naturally occurring pigments. The most dominant pigment in most plants (including cannabis) is chlorophyll, which, apart from helping plants photosynthesise, also gives them their green colour.

However, plants also have many other active pigments, including carotenoids and anthocyanins. In the absence of chlorophyll, plants may use pigments like anthocyanins to absorb sunlight and photosynthesise. Unlike chlorophyll, anthocyanins naturally absorb all wavelengths from the sun except those in the indigo spectrum, which is what gives plants their purple colour.

Hence, purple cannabis plants (or any purple plant for that matter) get their colour because the dominant pigment in their leaves and flowers are anthocyanins, rather than chlorophyll.


There are four main parts of your cannabis plant that can turn purple:

• Pistils: Pistils are the fine hairs that pop out of your buds, letting you know they’re female. Pistils generally start off a creamy white colour and turn orange/red/brown as plants mature. However, it is possible for your plant’s pistils to turn pink or purple, and this colour will remain after you harvest, dry, and cure your buds.

• Calyxes: Calyxes are the small pods that make up your buds. Cannabis flowers are actually made up of hundreds of these small calyxes stacked on top of one another. As the flowers mature, the calyxes open and reveal their pistils, which are designed to catch pollen from male cannabis plants.

• Leaves: The fan and sugar leaves of your cannabis plant can also turn purple. However, they usually won’t have a large effect on the final colour of your buds, as you’ll likely trim away most of the leaves during your post-harvest work.

• Trichomes: Trichomes are the tiny crystals that cover your buds. While they usually start off clear and become opaque and then amber later on, it is possible for them to turn purple, too.


Many people mistakenly believe that the best way to turn cannabis purple is to deprive their plants of oxygen. However, depriving your plants of oxygen, carbon dioxide, or any other gas will not improve your chances of harvesting purple buds. Feeding your plants more nitrogen also won’t change the colour of your plants, at least not unless you overdo it and end up burning them to a crispy shade of brown.

Some growers also use food colouring to dye their plants. And while it might work, we definitely do not recommend trying it. Finally, changing your plant’s light cycle, watering schedule, or grow medium also won’t increase its chances of turning purple, nor will yelling, screaming, or singing to your plants.


Now that you know how NOT to go about growing purple weed, here are a few pointers to help you maximise your chances of harvesting some eye-catching purple buds this season:


Genetics are going to have the biggest impact on the final colour of your plants. So, if you’re set on growing purple weed, shop around for purple strains, as they’ll have been specifically bred for their unique colour. Remember that your buds are going to lose some colour after trimming, so opt for strains with the most vibrant purple pigmentation you can find.

Keep reading through to the end of this article for some top recommendations on purple strains to grow at home.


While you might be eager to watch your plants turn purple, this will usually only happen once they’ve finished vegetative growth and start flowering. Once your plants have entered their flowering stage, try dropping your nighttime temperatures. Colder temperatures cause chlorophyll to break down and can encourage your plants to produce more anthocyanins. Ideally, you’ll want there to be a difference of 10–15°C between your daytime and nighttime temperatures.


There are some other ways to manipulate the colour of your plants. Most of these techniques, however, involve depriving your plants of certain nutrients, which, of course, we do not recommend doing. Even if you are able to achieve some purple colouration using these alternative methods, it will likely be to the detriment of quality, flavour, and potency.


Remember, the two main factors affecting the colour of your cannabis plants are genetics and temperature. If you’re really set on growing purple weed, make sure to invest in the right genetics from the get-go.

At Royal Queen Seeds, our expert breeders have bred some killer purple strains. Make sure to check them out and add a splash of colour to your next harvest:


Purple Queen is an almost pure indica variety bred from Hindu Kush and Purple Afghani genetics. She flowers over 9–11 weeks and produces big, purple buds with a uniquely pungent aroma that combines hints of both pine and fuel. Purple Queen also boasts a THC concentration of up to 22% and produces a nice, relaxing body stone that’s perfect for whenever you need to unwind and relax.

Perhaps you've seen brilliant purple bud. Perhaps you've even accidentally grown it. Now, you'd like to do it on purpose. Here is the ultimate guide to making your bud glow with that unique purple hue.