The flowering phase
The plant is fully grown and the end is nearly in sight. Now we are approaching the flowering phase, after which you can start harvesting. The first three weeks of the flowering or blooming stage are in fact more a growth phase. After the flowering phase of the plants has been initiated by setting the lighting to a schedule of 12 hours light and 12 hours darkness, they will start flowering and buds will start growing explosively. If you are growing outdoors this will happen as soon the days are starting to get shorter. In which week of flowering phase do the buds grow most depends on the strain and type of cannabis plant you are growing. They can easily double or even triple in size. For the sungrown cannabis the flowering stages are starting when the hours of sun or daylight begins to decrease. I remember the first time I ever grew a plant as if it was yesterday. I was amazed to see that the little plant quickly transformed into a giant. The buds keep swelling, the trichomes start being formed and the specific odor of the plant continues to develop, which makes it hard to wait until the buds can be harvested and you can enjoy the first joint of your own harvest.
Suzy’s Tip: Watch your plant closely and try to tell what it needs. Every plant blooms in its own way, so in some strains, the buds will grow from the beginning, while in other strains they will only grow in size and weight in a later stage. The needs of the plant can also change after a couple of weeks.
If you fertilize well, you actually don't need foliar feeding. Unfortunately, it is very hard to fertilize flowering cannabis well. Even if you think that you are giving the right nutrients, the plants may lack something. If so, you can administer foliar feeding to your plant. The nutrients are rapidly absorbed in this way and any nutritional deficiencies are corrected quickly. The chance of overfertilizing is minimal when administering foliar feeding. When growing inside, the best moment to administer foliar feeding to your plants is half an hour before the lamps go on. The light of the lamps is very powerful from the beginning, so you run the risk of burning the leaves if they are still too wet. Outdoor plants are best being administered foliar feeding early in the day, before the sun is too strong. It's no use giving them feeding when there is no light because then the plants don't grow and they don't need extra feeding. Besides that, you increase the risk of mold if they are too wet. Foliar feeding has to be sprayed on top of the leaves, once or twice per week. When giving foliar feeding, you also have to watch your plant closely to discover which nutrients it needs.
If space is limited, you might want to top or bind down your cannabis plants. Topping is removing the top of the plant. You will get two main tops instead of one. These do not grow as tall as one top but they yield more. You can bind a plant down by pulling the biggest bud down and binding it with slight tension. This will give you the same effect as topping, but you have the advantage that the largest bud is retained. The lower branches will develop better and the plant will grow bigger buds.
For a good flowering period, the plants need sufficient CO2 (carbon dioxide). They need this to grow powerfully during the hours that there is light. The more CO2 is present in the air, the faster the plants will be able to develop and the better they will be able to withstand high temperatures. You can use fans, but in good growing spaces, holes are made in the ground at one side to let air in, while at the other side an extraction system is installed as high as possible. This ensures an optimal circulation of air, from which the plants benefit by using the CO2-rich air that is continually circulating. Fresh air is continually sucked in through the holes in the ground. A fan is also very important. These do not only ensure good air circulation but also give the plants a pleasant breeze which will cause them to grow even better.
The period in which the buds of your cannabis plant start growing quickly is the most important in the flowering period. Depending on the strain, that's usually after about 3 to 5 weeks also called the end of the flowering period. But your should switch to flowering fertilizer just after the 3rd week and before the buds are starting to really develop. You can continue spraying your plant until then because the buds have not yet become hard and compact, but you shouldn't after that. So you can opt for preventatively spraying your plant. When the buds start growing rapidly, you can't do much more than administering blooming nutrients and enjoying the wonderful sight of the buds that are gradually being formed. More and more white hairs will grow and the separate little buds will steadily grow inwards to form one big bud.