Veteran marijuana smokers are always looking for something new to try. That goes for not just the effects of different strains of weed, but also the smell, taste, and even the color. The desire for novelty helps to explain why purple cannabis has been experiencing a rise in popularity in recent years.
While purple buds aren’t intrinsically any better than their ordinary green counterparts, many smokers prefer them. For some, a strain’s aesthetics mean just as much as its THC concentration and terpene profile, and that’s fine. Growers who want to cater to this consumer segment can read on to find out how growing purple cannabis seeds differs from growing green cannabis.
There are many factors that influence the color of mature marijuana buds, ranging from genetics to environmental conditions. At the end of the day, marijuana plants that naturally grow purple leaves, buds, or other parts do so because they are using higher levels of anthocyanin to capture energy from the sun. This happens when plants don’t produce sufficient chlorophyll.
Chlorophyll, the better-known of the photosynthetic chemicals, absorbs all visible wavelengths of sunlight except for green. This is what gives most marijuana plants, and other plants, their color. Anthocyanin absorbs all visible wavelengths except indigo and violet, which is why it appears to have a purple hue.
While many consumers prefer purple weed because they think it is inherently stronger than green buds, the fact that purple plants contain less chlorophyll and more anthocyanin actually makes them less potent. The indigo and violet wavelengths of light contain the highest energy, so reflecting these wavelengths instead of absorbing them means that plants don’t have as much energy to devote to growth. There are plenty of high-quality strains like purple kush and granddaddy purple that have been bred to produce high concentrations of THC, but they are the exception, rather than the rule.
Some strains of marijuana naturally produce purple leaves, stems, or buds. Growers who want to take the easy route can simply purchase high-quality seeds from plants that have been bred to favor greater anthocyanin production. As long as they follow marijuana growing best practices, they’ll wind up with purple buds without having to change their grow setups at all. Here are a few popular strains to try:
Most serious growers find that cultivating only a few strains of weed is too limiting. They should note that plants of any strain grown in the right conditions can produce purple buds. There are right ways and wrong ways to change the color of cannabis plants, so don’t take shortcuts. The only reliable way to grow purple weed from normal us seeds is to increase the day-to-night temperature differentials in the grow room.
Growers who want to produce purple buds don’t have to worry about making any changes to their setups during the seedling or vegetative stages. Treat the plants well and make sure they are healthy, but don’t do anything crazy like start depriving them of oxygen or applying food coloring to their root systems. Just treat them like a part of the rest of the crop.
It’s only once the plants have entered the flowering stage that growers have to start taking different steps to produce purple buds. Indoor growers who want to change the bud color of only a small percentage of their plants should note that they’ll have to set up separate grow rooms with separate temperature control before getting started. Move the plants to a different room after they have started showing signs of sexual maturity.
Leave the light settings the same in both rooms, but make sure the grow room for the purple plants is equipped with a solid climate control system. Growers will have to start dramatically altering their day to night temperature differentials right after moving the plants. To turn purple, marijuana plants must be exposed to changes in temperature of around 30 degrees Fahrenheit every night. If the daytime, or light exposure, temperature in the room is set to 80 degrees Fahrenheit, that means the nighttime, or lights-off, temperature should be around 50.
Quick temperature changes limit chlorophyll production and activity. Since chlorophyll is responsible for plants’ green pigmentation, this reduces the amount of green light reflected at consumers when they look at the plants. As chlorophyll activity decreases, anthocyanin activity increases, altering the wavelength of the light that appears to viewers. The same mechanisms are at work when deciduous trees start to experience changes in leaf coloration each autumn before they drop their leaves.
Don’t assume that more is better when it comes to altering nighttime temperatures. If the plants are exposed to nighttime temps below around 50 degrees Fahrenheit, they won’t be able to produce a good yield and, in some cases, may even die off before the harvest.
Although growers need to change their nighttime temps as soon as the plants enter the flowering stage, they likely won’t notice any changes in bud color until around two weeks before the harvest. Don’t get impatient and start further altering the temperature differentials. Either the technique will work, or it won’t. A variety of factors, from plant genetics to plant health, can also influence how effective it will be, but either way, green buds are still better than dead plants so don’t mess with the temperature range any more than necessary.
Most indoor growers simply set up a separate grow room and equip it with air conditioning. Setting up a small grow tent can also work as long as it is insulated enough to protect the rest of the crop from excessive temperature changes. Those who don’t have access to A/C can always move their plants outside if they live in temperate climates that get cool enough at night, but this reduces the ability to control for issues like pests and diseases.
There are no safe alternatives to either choosing strains with the right genetics or altering temperature differentials. Some growers swear by such foolish techniques as phosphorous deprivation, flushing with ice water, or even adding food coloring to the soil. Adding a slight purple tinge to the leaves by depriving the plants of the nutrients they need to grow and thrive or exposing them to food coloring or dye isn’t worth the tradeoff of unhealthy plants, decreased yield, and poor quality buds. Just don’t do it.
Growers who live in cooler climates may wind up with purple-tinged buds regardless of whether they want them or not. Those who live in warm climates often find that there’s nothing they can do to convince otherwise green strains like green crack or bruce banner to stop producing chlorophyll. In both situations, it’s best for outdoor growers to focus on strain genetics if they want to get beautiful, delicious, potent purple buds instead of attempting to control temperature differentials in an outdoor environment, which is next to impossible without an expensive greenhouse setup.
Growing purple buds may or may not be worth the extra effort depending on each grower’s unique situation. Home growers without many resources may want to try strains with genetics that predispose them to anthocyanin production, but likely won’t have it in the budget to construct an entirely new grow room just to grow purple crops. Growing purple buds from green strains can decrease potency, especially if it isn’t done correctly, so most home growers don’t find that it’s worth the effort.
Commercial producers should consider both growing purple strains and changing temperature differentials to give their customers more options. Many consumers will pay more for purple buds, regardless of whether it changes anything else about their smoking experiences. Even if they just like the novelty of it, commercial growers can still capitalize on the increased demand for different types of purple marijuana and can often charge more money for their crops than they otherwise could. Consider whether the ability to meet demand would increase profits to the point where building a separate grow room or changing the entire crop over to different day/night temperature differentials would provide a good return on investment.
There are two different ways to grow purple weed. Growers can either purchase strains that are predisposed to growing purple buds thanks to their genetics and use all the same techniques they do with the rest of their plants, or they can grow their weed a little differently by dropping the nighttime temperatures during the flowering phase to induce lower chlorophyll activity. These are both viable options, but growers shouldn’t let anyone convince them that other methods like nutrient deprivation are a good way to get purple buds. They’re actually a great way to ruin an otherwise good crop and should be avoided at all costs.
Thanks for reading this installment of the i-49 cannabis grow guide. If you want to want to get a smoking good deal on seeds for purple or green plants, come and check out our clearance seed section for the latest great strains.