Foxtailing? Do you agree?

Sorry for pic, not the best…but left side of bud seems to be Foxtailing.
Would you agree?

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Yes. What are your temps? What kind of light/wattage & how high is it above your plants?

Foxtailing can be caused by heat & light stress, but it could also be normal for the strain.


@blackthumbbetty Does foxtailing make for less potency or degrade it at all?

The fox tails will be airier than the rest of the buds, they’ll be hard to trim, and they’ll look weird, but they should still do the job. And do it well.

If heat & light stress are left unchecked, however, the cannabinoids could start degrading.


I had a lot of Fox tailing on my first two grows, especially on my white widow autos. I was told it can impact potency, but I was pleased with the product.

Light is 130w (true) about 10-12in from top for canopy… Only in the mid 70s for temp. Theres two buds doing it. And theyre not the closet.

Foxtailing can also be caused by genetics.

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Well, this is supposed to be bubblegum fem/photo. But its an autoflower…so i have no idea what it is.
Im thinking maybe the light, just a little to close.
Ima let it go and see what happends.

Thanks everyone. :smiley:

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It’s probably your light. That’s awfully close, even for just 130w draw light.


Here is a pic of FOXTAILING

What to Do About Marijuana Foxtailing

Picture some dried and cured, ready-to-smoke bud in your mind. Maybe it’s some you’ve harvested yourself,
maybe it’s some exotic-looking unique strain, or maybe it’s just a generic picture your mind pulls up
when you think ‘weed’.

I’m sure there are a few exceptions, but I’m betting most of you didn’t automatically picture this:

Picture of a cannabis bud with a major “foxtail” coming out the top. In this case, the foxtailing was
caused by too much heat, though some types of foxtails are caused by genetics.
See examples of “good” vs “bad” marijuana foxtailing below!

This picture is the definition of (one type) of foxtailing!

We tend to think of buds having a round, oblong shape with a pretty much even surface like this:

A marijuana cola with a typical shape.

The classic conical bud shape!
Many auto-trimming machines cut off foxtails, so if you used to purchase cannabis regularly you may
have bought buds with foxtails without knowing. That’s not necessarily a bad thing, though!

So, What Exactly Are Foxtails?

The bud we know and love is made up of a bunch of calyces (that’s the plural for “calyx”) and each calyx
is a potential home for a seed. However, those seeds will only develop in cases where pollination or
hermaphroditism (developing both male and female sex organs) occurs.

As female cannabis plants mature and soak up light, they grow calyces in groups which pile up on each
other until they end up looking something like the plant above. Even the more exotic looking strains
tend to form buds with a somewhat even-ish surface:

Buds are made up of many calyxes stacked on top of each other, but generally, buds grow evenly and stick
together in bunches.

Why, aren’t you exotic looking?

“Foxtails” are made of several calyxes stacked on top of each other in a relatively long structure.

Foxtailing bud is a bit different in that the bud has parts where calyces grow on top of each other to
form spires. These spires/towers throw off the overall shape of the bud as we’re used to, so they look
odd to most people. However, there are also plants that grow bud where all (or the vast majority) of
the calyces foxtail.

Even when you can very clearly see each individual calyx (which is natural for some strains), they tend
to be relatively symmetric, with a similar amount of “foxtailing” on all sides. (Why are these buds pink
and purple?)

Example of an exotic purple cannabis bud with natural foxtails

Cole train knows how to foxtail!

Note that on these plants, every calyx is foxtailing…even the calyces on the underside! It appears to
be the same action that’s happening in the picture above, but it’s much more complete.

So, is foxtailing a bad thing? It depends…

I know, I know…no one likes an ‘it depends’ answer. A ‘yes’ or ‘no’ would be a definitive answer and
it feels so nice to feel like you know something for sure! Luckily for us as growers, you can learn to
tell if the foxtailing you’re seeing is good or bad in just a few minutes! Now you can impress your friends!

Note: That was a trick! Impress your friends with cooking and/or Karate, but tell no one if you grow

The Two Types of Foxtailing
(Good vs Bad)

Before we go any further, I have to admit that designating one type of foxtailing ‘good’ is a bit
misleading. I call it ‘good’ in that it doesn’t provide any positive or negative benefits; ‘good’
foxtailing looks a bit funky but ultimately, it’s purely a cosmetic issue. However, ‘bad foxtailing’
really is a bad thing and comes with consequences…

Being able to tell if the foxtailing you’re experiencing is good or bad is as simple as being able to
tell the difference between two foxtailing pictures. Here are two more examples side-by-side:

An easy-to-compare picture with the two types of foxtailing

Let’s start with the one on the left. This type of foxtailing is caused by:

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
we’ll review in a minute.Dr. Grinspoon is a weird-looking form of foxtailing, but it makes good cannabis!

The picture to the right is a strain called ‘Dr. Grinspoon’ (named for the esteemed cannabis activiste
Dr. Lester Grinspoon). The look of this plant could be considered another manifestation of genetic f
oxtailing, and it’s important to note that this action happens everywhere on the plant.

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.

Now for the other picture. The other kind of foxtailing - the bad kind - is usually caused by:

Heat/Light Stress
The second cause of foxtailing is environmental and it’s usually caused by your lights. If you’ve
ever parked a high-powered HPS or LED light (CFLs and T5s aren’t usually strong enough) too close to
your cannabis, you might see it grow these odd spires.

A almost pleasant looking, but definitely bad manifestation of foxtails…

A strong foxtail spire caused by light stress!

The fact that the foxtails only seem to appear at the top means this is a bad thing…

What about when buds keep growing new white pistils over and over? This is another version of
foxtailing that is caused by heat and light stress. If it’s only happening to the parts of the
plant closest to the light, that’s a sign that it’s being caused by stress instead of genetics.

Example of heat and light stress - the extensive new growth at the top of the bud is caused by
the grow light being too close!

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!


Thanks for all the info on foxtailing, my plant top buds look pretty good a few curly caylyx. It’s all the buds below are loose long buds.


Is this foxtailing?

This is ILGM Sour Diesel Auto, 9 weeks in. This is for personal consumption, not for sale so I do not care what they look like. Just curious if the shape of these babies is as a result of my growing, or if this is normal.


Well i think any calyx that pokes out from the cone shape is a kind of foxtailing, I didn’t have many when I used burples, but since switched to hlg I’ve had that and continues to throw white pistols even when my tricomes say they should be done. Don’t get me wrong I love my lights they built awesome bud, they just kinda keep plants in hyper drive. Purple kush is foxtailing too and is a week from chop at week 11, it’s not too bad tho, just have bumpy nuggets lol

you got some good looking buds and still building man they are awesome :smile:


Foxtail city