Seedsman Blog

Cannabis Flowering Week by Week in Pictures 

There’s no doubt that the flowering stage is important when it comes to producing a great crop of cannabis. Over the next several weeks, you’ll find those buds developing and it’s a pretty exciting time.  

Of course, it’s vital to know what to look out for as things develop so that you know when to harvest at exactly the right time.  

To help you out, we take a long, hard look at flowering week by week in pictures. While plants can vary slightly in how they look, this should give you a great idea of what to look out for. It can help you plan better for harvest time.  

With all indoor photoperiod plants, you can decide when they go into the flowering stage. You do that simply by changing the amount of light they are exposed to. In the vegetative stage you have probably been using about 18 hours of light and 4 hours of darkness.  

Next it’s time to change this completely with 12 hours of light and 12 hours of dark. From now on, your flowers should start to develop the buds that are going to make up your next cannabis harvest.  

For outdoor plants, things are slightly different because it will depend on the daylight hours where you live. In most temperate places, you’ll find the flowers beginning to bud around September time and it’s just a question of keeping an eye out for the changes.  

There will be variations from strain to strain so don’t expect you crop to follow our example here 100% accurately. Certain phases may come on quicker or even take longer depending on a range of factors. Don’t let it worry you too much, every plant and environment is slightly different.  

Flowering Week By Week in Pictures 

It’s worth doing your research beforehand if you are growing your first crop. Taking a look at the following images will certainly set your mind at rest and confirm that everything is on the right track. Learning the various parts of your plant can help you identify changes easier and it’s worth doing a little bit of homework.  

Once you’re ready to hit the flowering stage indoors, simply change the lighting regime to 12/12.  

Week 1:  

By reducing the light, you’ve basically tricked the plants into thinking that the season has moved on and that winter isn’t too far away. They will enter into the stretch phase and put on a serious period of growth in preparation for flowering . You’ll see smaller leaves develop in abundance at the top of each cola.  

This is normally a good time to add extra nutrients to the soil as your plant is using up an awful amount of energy simply growing. Experts recommend you do this during the first week and also indulge in some light stress training (LST) if you want to improve the size of your crop.  

Week 2:  

This is about the time you may spot a few white pistils popping up if you have female plants. Males will tend to produce the first rudiments of pollen sacks which are different. Some seeds come with a mix of male and female so you’ll now be able to tell which is which. It’s important to separate the males from the female so they don’t start to pollinate. Of course, the female buds are the ones that you are going to be most interested in as these contain all the THC goodness.  

Most strains come with their own nutrient schedule so it’s important to check this and keep to it to avoid over or underfeeding your crop. If it isn’t provided with the seeds you bought, you can always check online.  

Week 3: 

In just the space of a few weeks your plant will have increased in size by about a half but this will now begin to slow down. On the female plants where you noticed hairs last weeks, buds will start to form. We’re now entering a pretty important stage and one where you need to be vigilant.  

Check that you’re giving the right food and that you have the doses figured out correctly. Check leaf areas for any signs that you are overfeeding such as the yellowing of leaves, particularly at the edges. This is a warning sign that something is wrong and is commonly down to what is called ‘nutrient burn’.  

Week 4: 

All the energy now is going into bud growth and you start to smell that tell-tale aroma as the buds get bigger and juicier. This smell is down in no small part to the trichome growth. The rest of the plant will have stopped growing completely now and you don’t have to worry about training the stems.  

Week 5:  

You will see the buds getting much thicker and new ones coming along which show that your crop is in good health. This means you have really gone deep into the full flowering stage so you might want to improve the air flow around your crop to disperse the smell which can become quite overpowering. This can also prevent problems like mold developing. 

This is the time when color changes start to take place in the flower. Those fine hairs which form the pistils may be turning darker or even amber colored. The trichomes, which were a bit harder to see, may start to turn milky. This means you’re not too far off being able to harvest your crop.  

Week 6 to 8: 

You’re now into the late flowering stage of the plants growth. This is the period when you are ready to start collecting those buds and start trimming. You can either go by the instructions you got with your particular strain or keep an eye on the buds themselves. This can be a pretty big judgement call and you need to get it right.  

Flushing Your Plants 

There are some things that you must do before you actually harvest, however. The first is called flushing. This basically removing the nutrients from the soil and replaces them with pH balanced water. It’s done normally about two weeks before the big day. This is not actually for the benefit of the plant but to get rid of nutrients that might well affect the taste/flavor of the final cannabis product once you harvest.  

Spotting the Right Moment to Harvest 

The one major thing you need to do is to pick the right harvest time. This is where you can rely on your strain information or, with experience, do it yourself. The latter is by far the best method.  

Invest in a jewelers eye magnifier and use it to take a long hard look at the trichomes. If these are relatively clear and transparent, you’re not yet ready. Once they start to change to milky white you should really be on your marks. You’ll see them start to change to an amber color and this is when your THC levels are really at the maximum.  

It’s time to harvest your plant! 

How to Harvest Your Cannabis Plant 

This is generally the most nerve-wracking time for newbies but it’s not something you should be afraid of. Our first big tip is to try not to touch the flowers more than you have to. You want to keep those delicate trichomes intact as much as possible and handling them can cause a lot of damage.  

The initial thing to do is get the large fan leaves out of the way so that you can see the rest of your plant clearly. These don’t have much value except for compost and can be discarded. The smaller bud leaves, however, have trichomes on them and are great for making edibles and hash oil. Carefully remove these and put them safe, working around the bud until you reach the sugary coating.  

Finally, cut the buds, leaving enough stem so that you can handle them without touching the valuable part of the plant. This is also a good time to check for issues like mold which can often be a big problem. If you spot it, make sure you separate the bud from the main crop and throw it away. Leaving can mean the mold spreads and contaminates everything else.  

Drying and Curing Your Crop 

The final stage is the drying and curing of your crop, something which needs to be done before it is ready to use. This can take anywhere from up to four to eight weeks and is just as important as any other step in the cultivation process. Get it right and you should have a cannabis crop that is smooth and flavorsome as well as potent.  

We hope that showing you the cannabis flowering week by week in pictures gives you a much better idea of what lies ahead and what to look out for. Understanding the various phases of cannabis plant development comes with practice and experience so don’t be too hard on yourself if you get it wrong first time. Treat it as a learning experience.  

Steven Meredith

Steven Meredith

Steven is a full-time freelance writer based in Wales. He joined the Seedsman team in 2018, contributing articles on a number of topics including global news, cultivation and strain profiles.