BackHow to grow autoflowers Part 2: Vegetative and flowering

This article is focused on what to do (and, above all, what NOT to do) to get the best out of your autoflowering marijuana plants. Growing large autos that produce abundant harvests is possible ― you just have to be up to speed with all the secrets of this type of genetics. Let’s get started!

 

As we explained in our previous article, the first few weeks of life of autoflowering seeds are crucial. While all marijuana varieties are at their most vulnerable stage during their first two weeks of life, automatic strains have the added disadvantage that their growth may become stunted if mistakes are made at this phase. When these mistakes are made, novice growers, or growers who have never tried auto genetics before, may end up with flowering plants the size of a bonsai. No need to panic, though, because these varieties are actually really easy to grow ― it’s just a matter of understanding that they have slightly different needs.

 

From the second or third week of life, you might start to suspect that something is wrong if your plant is still pretty small and hasn’t developed much in terms of lateral branching and internodes.

 

 

This autoflower is 2 weeks old and has stopped growing because the grower sprouted the seed when it was still too cold. Therefore, growth has slowed down and the plant hasn’t developed properly.

 

This becomes more evident from the fourth week of life. If the plant develops its first pistils but doesn’t reach a height of more than 5 - 10 centimetres, then there’s clearly been a blockage during its growth.

 

 

These autos are also 2 weeks old. You can see the difference in terms of development and overall appearance when compared to the previous photo.

 

If your plants are too small, you may have made one or more of the following mistakes in their first stage of life:

 

 

Whatever the reason, if your plant has become stunted and has already entered the flowering stage, you should evaluate the magnitude of the disaster and what the best options are. If the plant is really very small, you may want to start all over again ― the great advantage of these genetics is that they have an extremely short life cycle (8 - 10 weeks from germination to harvest), so you may still be in time to take advantage of the season and do things right from scratch.

 

Remember that all growers make mistakes, so don’t be discouraged but try to turn this mishap into a learning experience.

 

 

The plant that had problems during its first days of life (photo 1) has remained small. Although it still has some room for development during the flowering stage, it is pretty obvious that it won’t produce a good harvest.

 

If your plant isn’t explosive but still has a decent size, you may want to let it finish its cycle ― autos continue growing during the flowering period and can double or even triple their size in a matter of weeks. This is an extremely personal decision that will depend on your circumstances and on the resources that you have available: space, pots, number of plants allowed by law, etc.

 

 

The plants in the photo above have reached week 5. Their structure is well developed and, although we don’t recommend placing so many plants together in the same pot, the grower has been able to make the most of each day of their short autoflowering cycle.

 

During their first three weeks of life, autoflowering plants require more frequent watering sessions but with lower quantities so that they don’t drown. From the third week, they’ll have already reached a considerable size and developed a good root system, so they can perfectly absorb a normal amount of water (the same you would use for your photo-dependent genetics) without the danger that the soil becomes waterlogged for too long.

 

Remember that watering is one of the most important parts of cannabis cultivation:

 

 

One of the biggest mistakes you can make when growing automatic seeds is to perform pruning, such as FIM or topping, or to apply training techniques like SCROG or LST (Low Stress Training). Something very important to remember is that you don’t have the time required for these techniques to be effective, since the vegetative period of these genetics lasts only four weeks, so they don’t have enough time to grow and recover. There are some anecdotal cases of growers with a very advanced level of experience who have managed to multiply their autoflower harvests by applying training and pruning techniques. However, these unprecedented cases only occur when the grower has a very high level of expertise and perfectly masters indoor growing in advanced hydroponic systems. When performed with absolute precision, formats such as aeroponics can accelerate the growth and metabolic functions of the plants so they can develop the necessary branching for methods like mainlining to take effect. In our decades of experience, we have seen very few cases like these, and always in indoor hydroponic grows. So, unless you belong to this select group of little geniuses, forget about doing all the fancy stuff and just stick to what works. Another common mistake is to perform transplants, just as you would with photo-dependent feminised seeds ― this causes stress and can stop plant growth. All you have to do when your seeds germinate is to place them in their final pot (ideally at least 11 litre if you’re going to grow in soil).

 

As a final tip, don’t panic if the size of your plants in week 4 doesn’t exceed 20 - 25 cm and pistils are already beginning to appear. Some automatic varieties become taller than others during the vegetative period, but there’s no need to worry: autoflowering strains continue to grow and develop during the flowering, in many cases tripling their size.