The Importance Of Pistils To Cannabis Growers
Cannabis growers that understand the cannabis life cycle and can tell the difference between male and female plants before flowering will always enjoy more success than the witless weed grower. Pistils can tell you a whole lot about your cannabis plants. In this blog, we take a closer look at why they are so important.
WHAT IS A PISTIL?
A pistil is a female cannabis plant sex organ. To the ordinary decent home grower, a pistil is a hair that protrudes from a calyx on a female flower. They are also known as stigmas. When a pistillate hair comes into contact with pollen from a male cannabis plant, it is then pollinated.
Instead of focusing on producing more resinous flowers the female cannabis plant begins to develop seeds. The cannabis will be less potent, and seeds will form in the bracts that contain the ovule. Sensimilla, which means seedless, is entirely dependent on female cannabis plants not getting pollinated.
WHAT CAN A PISTIL TELL YOU ABOUT YOUR YOUNG CANNABIS PLANTS?
Typically male cannabis plants will develop preflowers sooner than their female counterparts in the cannabis garden. 3-6 weeks post germination you should be able to confirm that your feminized photoperiod seeds really are all females even if they are still in vegetative growth. Likewise, if you have regular seeds, you should be able to identify the male plants for removal before flowering.
Pistils tend to poke out from nodes pretty randomly on young cannabis plants. Carefully inspect your cannabis plants and you will spot preflowers sooner or later during vegetative growth. Sometimes they are obvious, close to the top of the plants and easy to spot. But this is not guaranteed so really examine the plants carefully.
Beside a stipule which is itself a green hair like growth on the stem, you will see the preflowers. You are hoping to see a wispy white hair at the node. If you see any kind of ball and no hair you’ve got a male. Until you can see a white hair emerging from a few nodes you really can’t be sure you’ve got a female cannabis plant.
You may have to wait as long as 8 weeks of vegetative growth with some strains to confirm female cannabis plants. However, after 4-6 weeks most growers can at least weed out the males. And keep an eye on one or two uncertain plants in early bloom if need be.
WHAT CAN A PISTIL TELL YOU ABOUT YOUR MATURE CANNABIS PLANTS?
Autoflowering cannabis plants tend to suddenly erupt with flowers quicker than you would expect. Somewhere between day 15-35 post-germination, your feminized autoflowering cannabis seeds will have multiple white pistils bursting forth from the first flowers. A week or so later and buds are beginning to swell up with calyx’s and sparkling with resin. Pistils will rapidly change colour from white to orange/red in days rather than weeks.
With photoperiod cannabis strains’ flowering has three sub-stages: early bloom, mid-bloom and late bloom. Pistils are a great indicator of how your female cannabis plants are progressing. With the onset of a 12/12 light cycle, the pistils will be completely white. Somewhere around week 4-6, midway through flowering, is when the first orange, red and/or pink colours begin to emerge and proliferate. Not until sometime during weeks 7-10 following a good flush with pure water or a light flushing solution will a majority of the pistils be beautiful ripe shades of red, orange and brown.
DO ONLY FEMALE CANNABIS PLANTS HAVE PISTILS?
Female plants and intersex plants will display pistils. Unfortunately, intersex plants will also produce pollen and are as great a threat to your females as a rogue male cannabis plant. Moreover, stress can cause any cannabis plant to develop intersex traits. Some varieties of industrial hemp are bred specifically for their hermaphrodite characteristics.
Do you want Sensimilla? Then you need to make sure none of your female plant’s pistils get pollinated. This means you must continue to monitor your plants throughout flowering. Disturbances in the dark cycle are perhaps the greatest stress factor that contributes to hermies.
HOW CAN PISTILS HELP YOU DECIDE WHEN TO HARVEST?
Before the advent of microscopes and zoom lenses, ganja farmers had to rely on their intuition when harvesting cannabis. The good old-fashioned eyeball inspection of cannabis flowers is a tried and trusted pre-harvest practice. When 75% or more of the pistils are full of vibrant colours, most cannabis growers will call time on cultivation. Flowers covered in red, orange, pink and brown hairs are definitely mature.
Without advanced optics, you’ll also be able to see the shimmer of trichomes. Besides, buds will be sticky to the touch — although you shouldn’t handle them excessively unless you’re making charras. Furthermore, the pungent aroma of ripe reefer should be a loud cue your female cannabis plant is finished. All five senses have a role to play. Pistils are a valuable visual aid throughout the cannabis lifecycle.
Whether you grow your weed from autoflowering, feminized or regular seeds, it pays to know about pistils. Here’s what every cannabis grower needs to know.
Why Some Buds Keep Making New Pistils
If you’re lucky, your cannabis plants buds will all be ready for harvest around the same time as their neighboring buds. However, some cannabis strains naturally finish their buds at the top of the plant first, while other cannabis strains do the opposite. When buds are at different stages of maturity depending on their location on the plant, it can be hard to know when to harvest!
It’s okay to harvest your cannabis plant in parts!
Most growers choose to harvest the entire plant at once, but some cannabis strains make that difficult. For example these buds are at very different stages of development even though they’re on the same plant at the same time!
When parts of the plant mature faster than others, it’s completely okay to harvest in parts starting with the most mature buds. Then you can harvest the rest of the buds as they appear ready.
Many growers accept that some buds are going to be at different stages of development and just try to harvest the plant when most buds look the most ready. That might even be a good thing since you get to try out the slightly different effects from harvesting buds at different stages!
But sometimes you’ll have a case where a marijuana plant keeps making more and more new pistils right when the plant seems just about ready to harvest. Often you can tell something is not quite right…
When is it not normal to keep getting new pistils?
It’s not normal when your plant is making new pistils only on the parts of the buds that are closest to the light. This can stress the buds by heat or because the light levels are too high.
Note: If your plant is also growing weird, round leaves, it’s possible your plant is revegging.
Never-ending pistils is most likely to be heat or light stress if the buds seem to be losing their round, pointy shape from the new growth.
Buds growing in strange shapes can be a sign of heat or light stress. This plant got new buds growing with white pistils right as the rest of the buds started looking done. Each new bud or “foxtail” is covered in lots of new sugar leaves because the plant is actually growing brand new buds like towers or mini colas emerging from the old ones.
Another very common sign of heat or light damage is when buds are becoming fist-shaped because of new growth, especially if it’s happening mostly on the parts of the buds closest to the light
In the following example, the cannabis bud has been damaged by both too much light and too much heat. Although the rest of the buds on the plant appear almost ready to harvest, this bud closest to the light keeps putting out more and more white pistils as new buds grow on top of the old one.
Sometimes you see long and thin foxtails on the sides closest to the light. Luckily, buds formed as part of foxtails or heat stress are just as good to smoke as any other buds, despite their unusual shape 🙂
If you see these symptoms, you should be looking at the older parts of the buds to decide when your plant is ready to harvest. Don’t pay attention to the newest growth because it will look immature even if the plant is ready!
What to Do If It’s Heat or Light Damage
- Look at older growth to decide when to harvest, not the newest parts
- Control the heat if you can! Getting the top canopy a few degrees cooler can make a huge difference in your efforts to stop foxtailing!
- Even if the temperature is okay, move your grow lights further away if possible because sometimes bud damage is caused by light burn. Light stress without heat is most common with HPS and LED grow lights that are kept too close.
- Any buds formed this way are still perfectly good to use for smoking, vaping, edibles, etc. For cosmetic purposes some people reshape buds during the trimming process, but it’s a matter of personal preference!
- Consider giving your plant shorter days (longer nights) to “hurry” it to finish flowering. By giving plants a 11/13 or 10/14 light schedule (13-14 hours of complete darkness/day), you will encourage your plant to finish flowering sooner.
When is it Normal for Buds to Put Out New Pistils?
It’s important to remember that it is normal for some strains to put out new waves of pistils two or three times during the flowering stage, even without heat or light damage.
Sativa strains tend to do this the most, though it can happen to many different types of strains. Sometimes the new growth may even look like fox tails, but if it’s happening evenly all over the plant chances are it’s normal and caused by the strain 🙂
Fox tails and new white pistils are normal if they’re staying small and happening evenly all over the buds. This type of fox tail is caused by the strain, not heat or light stress. You see this most commonly on Haze and Sativa strains.
Speaking of Sativas, did you know that some Sativa and Haze strains will usually not make any amber trichomes? If you’re waiting for trichomes to turn amber before you harvest a Sativa strain, you may be waiting a long time. If your plant has been flowering for more than 3 months, sometimes it’s best to wait until the trichomes are mostly cloudy and go from there, without waiting for any amber trichomes.
If your Sativa keeps putting out more and more pistils in a healthy way, and you want to “hurry it along,” you can reduce the number of hours of light they get a day from 12/12 to 11/13 or even 10/14. Giving plants longer nights during the flowering stage causes them to mature faster, and it may be needed to get Sativa strains (some of which come from the equator) to “finish up” in a reasonable amount of time.
More Examples of Heat-Damaged Cannabis Buds
One of the things that many growers immediately notice about heat damaged buds is they keep growing tons of new sugar leaves. Since the plant is no longer in the vegetative stage it won’t make regular fan leaves anymore, but it still will desperately try to grow new leaves to power the growth of these new buds.
Some strains naturally grow more sugar leaves than others but when there’s tons of them and the sugar leaves themselves look odd like this (and the odd growth happens mostly to buds closest to the light) you know for sure it is not normal!
In the picture below, the grow space wasn’t even hot at all. The buds started foxtailing because the LED grow light was too close and the plant started getting light burn. Your plants can be burned by too powerful light even if it’s the right temperature.
This fist shaped bud keeps putting out new pistils on top as a result of heat damage. The rest of the plants already looks completely ready to harvest! In this case, ignore the top pistils and harvest the plant 🙂
Here’s another example of a fist-shaped bud with tons of new white pistils and sugar leaves on top as a result of stress. This case was caused by an LED grow light being kept too close even though the temperature was good.
These buds were also affected by LED grow lights being too close. Notice the odd-shaped buds near the top of the cola. In contrast, the lower buds were shaped normally.
When I first started growing I didn’t realize what was happening when I saw fox tails and strange bud shapes on my cannabis plants. I didn’t realize my plants were trying to tell me something! Now that you know what your plant is saying with its bud shapes, you know what to do!
Some cannabis strains mature faster on top, while others mature faster on bottom. But some plants keep putting out waves of brand new white pistils on top buds, and that can be a problem.