In week 5 of flowering, you can observe the buds all over your plant becoming thicker. You may also spot new buds growing in new places such as along the main cola. With buds abounding, your cannabis plants will get fatter every day. This is a surefire sign you are in full flowering mode.
At this point, your plant will have a very intensive odour. Ensure that you have a good ventilation system in place if you grow indoors or in a region that doesn’t allow for legal cultivation. Some of your cannabis plants’ previously white pistil hairs may now be turning darker into a brownish or amber colour. At the same time, when you check the trichomes of your plant, you may spot some of them becoming opaque. The trichomes becoming milky white and the hairs turning darker are all signs of your plants not being too far from harvest. WEEKS 6, 7 AND 8 (LATE FLOWERING STAGE, RIGHT BEFORE HARVEST) Not all cannabis strains require the same amount of time for their flowering, but many varieties will be ready to harvest in these last three weeks. There are, however, not too many strains that will be ready before week 8. Depending on the flowering time of your particular strain, the time for flushing your cannabis plant is normally two weeks before harvest. When you “flush,” you stop administering nutrients and give the plant only plain, pH-balanced water in these final weeks.
This will get rid of (flush out) salts and minerals in the soil which will make for a better and more pure-tasting bud. Otherwise, your smoke will be quite harsh and can have an unpleasant, chemical taste. To find out when it’s time to harvest your plant, you can use a jeweller’s loupe or a small microscope to regularly check your plants’ trichomes. You can observe whether the trichomes turn from clear to a milky white colour. If many of the trichomes you see are still clear and transparent, it means it’s still too early for harvest. But when most of the trichomes have an amber colour and an opaque clarity, this means that the THC content of the buds is at its maximum and the plant is ready for harvest. Timeline of the Cannabis Flowering Stage (12/12 to Harvest) Table of Contents. Week 6-8 – Buds Ripen, Pistils Darken – some strains spend longer in this stage. During the phase of life known as the vegetative stage (the first stage of life for marijuana), a cannabis plant grows about how you’d expect… like a weed! In the vegetative stage a cannabis plant only grows new stems and leaves, and can grow several inches a day with the added ability to recover from just about anything! Even if you run into major problems in the vegetative stage, you can bring your plant back from the brink of death simply by addressing the problem and giving your plant some TLC. In the vegetative stage, your cannabis plant only grows stems and leaves and is resistant to problems. However, things aren’t so rosy in cannabis flowering stage. In the flowering stage your cannabis plant grows very differently, and is much more sensitive to problems. The tricky thing about the flowering stage is that you don’t have much room for error and big mistakes can lower your yields. In order to maximize your yields, it’s important to know what to focus on during each part of the flowering stage. It’s also really helpful to know what to expect so you know when something is going wrong! This flowering stage “walk through” will explain exactly what to expect week-by-week while your plant is making buds, and it’ll tell you what you need to do to ensure you get to harvest with the best bud quality and yields possible! When growing cannabis indoors, the flowering stage begins when you change your grow lights to a 12/12 light cycle (12 hours light, 12 hours darkness each day). Getting those 12 hours of uninterrupted darkness each day gives your plant the signal that it’s time to start flowering. In a way the plant “thinks” winter is coming because the days are getting short. Note: It’s common to think that a cannabis plant getting 12 or less hours of light is what initiates flowering, but it’s actually uninterrupted darkness that does the trick! If the plant gets any light during the dark period, even for just a minute, it won’t make buds! In fact, a flowering plant may even revert back or express hermaphroditism if it gets any light at night! Outdoors, it’s also the days getting shorter that cause a cannabis plant to start making buds in late summer, but outdoor buds develop on different schedules depending on the local climate. This tutorial is meant to explain how a cannabis plant usually develops when grown indoors, since that is done under controlled conditions, and plants tend to grow the same way.
For the purposes of this tutorial, the flowering stage starts the day you switch to 12/12. Autoflowering strains of cannabis don’t need special light periods to start flowering, however the cannabis flowering timeline in this tutorial is a good general guideline for indoor auto-flowering strains, too. Their “vegetative stage” lasts about 3-4 weeks, so as long as you start counting at week 3-4 from seed (when they start getting their first pistils) this flowering timeline will generally apply to autos too, though sometimes they finish up faster.
During the first few weeks after being switched to a 12/12 schedule, your plant will be growing like crazy and rapidly gaining height. In fact, a cannabis plant can (and frequently will) almost double in height after the switch to 12/12.