What Is Cannabis Foxtailing?

What Is Foxtailing?

Foxtailing is the occurrence of large pillars of calyxes on cannabis flowers. If the cause is genetic, then there is nothing to worry about. If the cause is environmental however, your plants may be subject to excessive levels of stress.

Foxtailing is a phenomenon that drastically changes the physical appearance of cannabis flowers. Usually, healthy and “normal” cannabis flowers take on the form of a compact nugget. This sight is pleasing to the eye and therefore critical to those cultivators looking to boost the chances of selling their crop. Buds that start to foxtail look entirely different from this typical image, taking on the appearance of a large pillar or tower that is made up of buds and leaves layered on top of one another.
Normal cannabis buds are comprised of groups of calyxes. These structures are responsible for bearing the seeds of the plant if pollination takes place. When foxtailing occurs, calyxes begin to stack on top of each other instead of cluster together. This creates the appearance of a tall, brush-like structure that is not dissimilar to the tail of a fox. This is very different from the more symmetrical nature of most buds.

Although foxtailing looks quite strange and is different from the norm, it isn’t exactly negative. There are two primary factors that account for foxtailing. One of them is genetics. If a plant is genetically predisposed to form buds in a foxtailing fashion, then there is absolutely no cause for alarm. The second has to do with environmental stressors. This scenario is less ideal and usually occurs in strains that are not genetically predisposed to foxtailing.

The Two Types of Foxtailing: Good vs. Bad

 Example Of Good Foxtailing

Foxtailing is only a negative occurrence in some circumstances. If the cause is a genetic one, then foxtailing should not be perceived as bad. In this instance, it is a perfectly natural process and isn’t an indication that the grower might be making a few mistakes. Genetic foxtailing does cause plants to display a rather unique structure, but it doesn’t detract from the quality and potency of a crop. The strain Dr. Grinspoon is a good example of a genetic that causes natural foxtailing. In this case, the appearance is so distorted that it looks as though it belongs to a different species entirely.


Some strains of cannabis have been bred – by humans and/or mother nature – to form buds where foxtailing is the norm. Although often foxtailing is caused by heat or light stress, when you’re growing a strain that is genetically predisposed to foxtail, the whole bud joins in on the foxtailing action. This makes it so that genetic foxtailing looks more uniform than the other type of foxtailing.

Good or Bad? In short, there’s nothing wrong with genetic foxtailing. The fact that it’s genetic means that it was going to do it regardless of whatever specific growing technique is being used. These strains are also capable of containing high amounts of THC, so it doesn’t seem that genetic foxtailing reduces the potency of the plant.

This type of foxtailing is the good type. Again, that only means that it’s good by comparison to bad foxtailing in that it doesn’t cause any negative effects.

Example Of Bad Foxtailing

Negative foxtailing occurs when the process isn’t native to the strain. This can be caused by multiple external factors, namely heat and light stress. If a grower has strong lights positioned too close to the top of their plants, it may expose the crop to an undue amounts of stress that causes the physical structure to change. The excessive light and heat received by plants is a cause of unnatural foxtailing that will encourage large and dense growth. These towers may look pleasing to the eye and it may almost seem as if foxtailing has caused larger yields; however, this plant matter will have lost potency and will continue to do so unless something is done to remedy the situation.

Good or Bad? Bad! This type of foxtailing is a sign that your buds are getting too much light and/or too much heat! These odd spires can also be accompanied by light bleaching and cooked leaves. Any one of these signs is a message that your lights need to be backed off immediately to halt any further damage. Although light bleaching and burned leaves are obviously damaged, foxtails don’t look damaged so much as they just look weird, so they don’t register as a threat to new growers. Unfortunately, they’re the harbingers of heat damage which means lost potency; if you see this type of foxtails on your buds, you’ve likely already lost potency to heat and now the mission is to lose as little as you possibly can.

Luckily, this type of foxtailing is usually localized, so you’ll only see it in spots where light intensity is super-high. This usually means they’ll be found in a small circle directly under the light, but that small circle gets larger as the light gets closer.


Now with all that being said, plants are weird! It’s totally possible that many of you growers have already seen a plant that makes the ‘bad’ looking foxtails but all over the plant. Or maybe a plant that only grows in spires! The point is that there is bound to be plants that break these rules, but at least until then you’ll know what you’re dealing with. Good luck and happy growing!