When to harvest cannabis plants?
There are many reasons why growing weed for personal use may seem like a good plan but is harder than you think. The apparently simplest things are often the most difficult when growing weed. Most mistakes are made with things like watering or feeding. Besides, too many weed plants are still harvested way too early by impatient growers. Anyway, how exactly to determine when to harvest cannabis plants and why is it so important to choose the right moment?
Harvesting cannabis plants at the right time not only affects the overall quality but also the yields. Harvest too soon and your weed will be too weak; harvest too late and it will send you to sleep. But how exactly can you tell when the right time arrives? This article will explain everything you need to know about when to harvest your cannabis crop.
When is my weed ready for harvest?
There are basically two methods you can use to determine whether your cannabis plants are ripe for harvest or not. The first method is a visual method and involves simple observations of the hairs on the pistils, the technical name for the female reproductive part of the cannabis flower. The second method – the trichome method – is a bit more technical. Let us tell you how to know when to harvest your weed plants, explore what both methods involve after which then you can decide which one is right for you or use a mixture of both.
1. The Pistil Method
If you prefer to operate in a more down-to-earth way and feel in tune with your growing plants, the observing pistils (hairs) method could work for you. Besides you don’t need to buy any equipment as long as your eyesight is working well so this method is ideal for those on a budget.
You need to know the signs that indicate your plants are ripe enough to be harvested. Look out for long white threads (the flowering hairs) that come out of the flowers.
The flowers of a female weed plant have long, white, thick hair during the flowering period. These hairs are most often a whitish color during flowering. When about 80% of these white hairs have turned brown, it is time to harvest, although there are exceptions to the rule, depending on what you want from your cannabis plant and on the strain.
Wait until no new white hairs appear in your buds. You will notice that the buds will have started to smell very strongly by this point in the cycle, the entire nursery or grow room will probably smell strongly of weed. The buds also look thick, bulgy and properly padded – mature and ripe, in other words.
40% of the white hairs are brown and dried up
Wait until at least 40% of the white hairs on the tips are brown and dried up. When this is the case, you are at the start of the harvestable period. If you harvest your weed at this moment it will give you a more energetic effect when it is smoked and the weed is not yet at its peak in terms of potential.
40% – 50% of the white hairs are brown and dried up
When 50% to 70% of the hairs are brown and dried up, your weed is at its peak in terms of potential. Your weed now contains the most THC. So if you are looking for potency, now is the time to harvest your weed.
80% – 90% of the white hairs are brown and dried up
When 80 to 90% of the hairs on the tips are brown and dried up, your weed has passed the peak of THC. The weed that you now harvest will give a more relaxing effect that makes it harder to get up from your couch. This is because part of the THC in the weed has been converted into the more relaxing CBN. People who are looking for weed with good painkilling properties would be well advised to harvest their weed at this point.
However, the harvesting time also depends on the species. Some types of weed need to flower longer than others. With some, the flowering process starts later and with some earlier. Yet, the above information provides a pretty solid answer to the question: when to harvest cannabis.
The aforementioned advice is a good guideline but you should be aware that with some strains, it can be much more tricky to work out if the plant is ripe to be harvested. Different strains of marijuana can present in different ways when they are ready for harvest. Some varieties, for example, manage to retain most of their hairs white even when they’re more than ready to be picked.
If you suspect this might be the case for your cannabis plants, the best thing to do is to find out as much as you can from someone who has successfully grown your variety before. This might be the breeder or a grower. It’s also sensible to look for online images of the appearance of your strain when it is ready to be harvested.
Other signs that indicate it’s time to harvest:
- The plant looks less healthy, leaves start to droop, and the number of yellow leaves increases at the bottom.
- The weed plants will stop being so thirsty and use much less water than before.
Warning: Do not grab the buds or manhandle them too much during the flowering period, this will damage the flowering hairs and cause them to die and dry out. Buds that are grabbed very often sometimes even look ready for harvest because all the delicate flowering hairs are damaged by grasping and turn brown as a consequence. You need to be gentle!
2. The Trichrome Method
This method is a bit more technical and does require a bit of scientific knowledge, but if you want to grow cannabis for its THC levels, this method will give you a much higher level of accuracy. Never fear, this article will give you all the info you need to become a cannabis trichome expert and harvest your crop when it is at its pinnacle in terms of THC and other goodies.
What exactly are trichomes?
Trichomes are very important as they are responsible for the THC of the weed plant, the very substance that makes you high. If you look closely at a weed plant in bloom, you will notice very small stems with bulbs on them. These are trichomes but they are pretty hard to see with the naked eye.
With this in mind, you may benefit from using the following magnifying tools to make inspecting of the trichomes easier and more accurate. Using one is not completely necessary but will help you get the timing of your harvest perfectly right.
Jeweller’s Loupe – A jeweller’s loupe is a compact round magnifying glass that is inexpensive and yet more than capable of getting the job done. A cheap one should give you a 40x magnification. You simply hold it over the blooming cannabis plant and peer through the glass.
Digital Microscope – This has to be one of the best gadgets to calculate the right harvesting period. Digital microscopes are available to suit all budgets, but a good-quality digital microscope can now be purchased for under £50 and will allow you to view images of the trichomes on your laptop or any connected device. They are ideal if you want to share images of your trichomes and canvas second opinions.
Now comes the technical part; what to look for when looking through your microscope or jewellers loupe:
The trichomes you are attempting to observe look a bit like tiny mushrooms. You may also notice minute, transparent hair-like trichomes minus the mushroom head. These are unimportant as they won’t have any impact upon the final strength – you need to pay close attention to the trichomes with the little ball on top. It’s this tiny head that holds the power as this is the location where most of the THC and other key chemical properties of cannabis, such as CBD and CBN are concentrated. As these trichomes are the most responsible factor regarding bud potency, knowing how to tell when they’ve achieved their highest THC levels will help you determine exactly the right time to begin your marijuana harvest.
Look for the following signs which indicate when it is time to harvest:
- Clear trichomes If all the trichomes on the plant are still clear or transparent, it is too early to harvest. The plant is not yet fully ripe and should be left to flower for a while longer. However, for inexperienced growers, it can be difficult to judge whether a trichome is clear and glass-like or cloudily opaque. This is where the advantage of a digital microscope that can capture images and allow you to compare online later really becomes crystal clear.
- Clear and milky trichomes If most trichomes begin to turn whitish, you could potentially harvest now – the results will give an energetic vibe and a nice euphoric feeling after smoking.
- Yellow trichomes If you are going to harvest now, you will get a narcotic high which is good for insomniacs.
- Mostly yellow with some whitish trichomes If you were to harvest your plants now, the resulting weed would generate a nice buzzy stoned feeling in your head and body.
- Only brown trichomes Oh dear, you’ve left it too late, the plant has passed its best time. If you harvest now you will have little or no effect from the THC. Better luck next time!
Summary: General tips and tricks
Growing and harvesting marijuana takes a moderate amount of gardening skill and there are always new hints that can provide additional insight. Here is some additional advice about harvesting cannabis based on the colour of the hairs and the state of the trichomes. Follow our rules and you’ll stand a good chance of harvesting perfect weed every time!
- You can tell that your plant is too immature for harvest if it still has white “hairs”, the majority of which still stick straight out; especially if its trichomes are all still clear. Harvesting now will result in low yield and non-potent harvests. Wait until your plant has ceased growing new white pistils and lots of the white hairs have turned into an amber brown and curled inwards.
- THC is at its strongest when most of the trichomes look milky white when observed under a microscope. Approximately 50-70 % of pistils have been browned and harvesting now will lead to a more trippy weed. However, some strains, such as Sativa and Haze have trichomes that never really turn amber. If they’ve turned white for a while and haven’t changed for a few weeks, you may need to get harvesting.
- If you want weed that will get you properly stoned, you need to aim to harvest at the end of the season, when most of the trichomes have turned into a dark amber or gold shade. Experts say that amber trichomes derived from Indica varieties produce the best body highs. A good proportion of the THC will have converted into CBN which is far less psychoactive and is known for its calming and anti-anxiety effects.
- Colour disparities – Don’t be alarmed if you notice red or even purple trichomes – this is normal for some strains. As a rule of thumb, harvest when the majority of pistils are nice and dark.
- Don’t leave things too late If you spot trichomes looking grey or shriveled, you have missed the harvest window. Harvesting now and the end product will make you drowsy without any other pleasant effects. This is not a common problem though, as most growers are far too eager to get harvesting and you the harvest period open for about four to five weeks.
- Cure your buds properly. Curing them for about a month will increase their anti-anxiety and calming properties.
- Do things in stages If you are feeling excited about harvesting your marijuana plant, pull buds off the plant that look the most mature, dry them and check the potency for yourself. You can do this over a few weeks. Harvesting the buds in stages (starting off slowly with small batches) is a good way of abating the excitement. It will also help you work out where your preferences lie. There is nothing wrong with cutting off a few pieces in a go.
- Follow your gut instinct Cannabis harvesting can seem daunting but always listen to your instincts. We think that using a combination of both methods is the best way of helping you choose the optimal time to harvest, but knowing how you want the end product is a very personal thing. This means that even the best methods are just general guidelines. But hopefully, you’re now closer to getting your weed the way you want it.
Final hints before your harvest
1. Be prepared – Before starting your harvest, it is handy to arrange everything in advance, ensure a clean environment, good clean scissors, possibly plastic gloves, and make sure your drying loft is ready to be used. You don’t have to go to the extremes of Walter White in ‘Breaking Bad’, but it’s good to get organised. Start by cutting away all the large leaves, leaving a plant with many small leaves and no large leaves. Cut away half a centimetre of leaves around your buds, the protruding weed leaves will dry and shrink. You could possibly leave THC on it.
2. How to physically harvest the cannabis plant – There are several methods, it really is a matter of trial and error and personal preference.
Leave the plant in the pot or soil and cut off the large leaves. Then cut away the small leaves around the tops so that you end up with a bare plant with only the flowers. You cut a branch every time and cut the leaves off again. So you can cut the twigs per piece, this is a bit more convenient because you don’t have to turn your plant every time.
You can also cut your weed plant in its entirety and lay it down to cut off branches.
Related article: how to harvest weed?
What can you do with leaves or cutting waste?
After harvesting, you have a whole mountain with leaves and clippings. However, many of these residues can still be used for processing in recipes or tea. You can also compost any unwanted vegetation.
You can do a lot of fun and useful things with the waste, but it is important that you know which leaves you should throw away and which leaves can be used.
Cannabis, weed, pot, herb – the list of names for the wonderful plant is endless, but, as you can see, the knowledge of when to harvest, while not completely straightforward, is, nevertheless, less complex than it might first appear.
Our advice is: follow our tips, read as much around the subject as you can – our blog posts are a good starting point – and talk to as many experts as possible. You’ll be an experienced cannabis cultivator before you know it!
Wondering when to harvest weed plants? Cannabis harvest time is determined by 2 methods. Check this blog and learn when your weed is ready to havest!
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.