End of the blooming period
The last weeks of the flowering phase
After weeks of increasing tension and enthusiasm, the long-awaited moment of the harvest has finally come. Your plants should look magnificent now. You probably have a hard time waiting to smoke your first homegrown joint but have a little more patience. You only have to wait a little while now and then your time and energy will be greatly rewarded. As soon the light cycle is on 12/12 hours dark/light the buds are starting to form and swell. The plants have grown a lot in the first weeks of the flowering period and underwent a real transformation, after which the formation of the buds began. More and more white hairs were growing and the separate little buds steadily grew inwards to form one big bud. After about five weeks of flowering, there will now be hard, crystal-rich buds on your plants. How much weight do buds gain in the last weeks of flowering depends on the strain. They should still be beautifully green and the buds should still be growing, even though the major part of their development has already been completed. Production of THC is now at full speed. The leaves around the buds will become increasingly sticky because of the many THC-rich resin glands that are growing.
Now the harvest is getting closer, it’s time to remove the leaves around the buds and the bigger leaves that contain THC. This can also be done later on, but if you do it now, you save time and more light will fall on the lower buds, which allows them to grow a bit more at the last moment. You can dry these leaves to make kief, hash, hash oil or ice hash from it.
Because blooming plants need more phosphorus and potassium, you can give them PK 13/14 as an additional stimulant for their growth and flowering. It will make the buds harder and more compact. You can also administer additional products such as blooming stimulators, blooming boosters, and enzymes. If you are a beginning grower, these products are probably superfluous because they are only of use if everything went well during the growth period. There’s a fair chance that you will have made some mistakes if you are a beginning grower. If you are an experienced grower, these products will enhance your harvest.
In the last two weeks, the buds will mainly mature and grow no more in size. The white trichomes (small resin-secreting stalks/hairs) on the buds will now slowly turn brown.
Because there are still a lot of nutrients in the medium (the precise amount depends on the medium you used) and because the leaves also contain a fair amount of nutrients, you can stop administering them in the last 1.5 to 2 weeks (depending on the medium you use). Depending on the cannabis strain you grow and the climate of the growing area, the maturing takes some time to complete.
Try to make sure that the humidity stays below 50% in the last few weeks of the flowering period. If the humidity is too high, this can lead to stone hard buds, which might develop mold in the last weeks of their growth phase.
If you have discovered mold in a bud, it is as good as lost. Once 80% of the hairs have turned brown, it’s time to prepare for the harvest. The ideal temerature during the flowering phase is between 20° and 29° Celsius. You can influence the type of high you get from smoking your cannabis by harvesting the buds a bit sooner or later. The longer you wait, the stronger the ‘stone’ of the cannabis will be. If you harvest a bit sooner, you get more of a ‘high’ effect. The harvesting time, therefore, depends on your personal preference.
A bud that died or has been infected by mold will also develop brown hairs. You can start harvesting when 80% of the hairs are brown. If most of the buds have brown hairs but a couple of the lower buds still have white hairs, you can still start harvesting. In order to try out the different highs, you can also harvest in phased intervals.
Flushing means rinsing the medium in which the cannabis plants are. Growers then flush with water only. By rinsing you remove all nutrients, bacteria and micro life from the medium. Many growers flush in the last cultures of flowering to improve the taste. The plants break down the chlorophyll and convert it into energy. The buds are not growing in size during flush. The plant yellows and dies. That is actually a shame since you deny the plant the necessary nutrients in a crucial phase. Growers that flush too early therefore miss out on yield and quality. Those who do not flush should cure at least 3 weeks.
The plants have grown a lot in the first weeks of the flowering period. After 5 weeks of flowering, there will be hard, crystal-rich buds on your cannabis plants.
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.