The following guide is based on an autoflowering cultivar that takes 10 weeks from seed until harvest.
After 7 days the seedlings will begin to grow taller increasing the size of the fan leaves. During this time the plants are in a vegetative state so they will rely on Nitrogen, Phosphorus, and Potassium as well as trace elements to aid in foliar development, stem production and root production.
1. The Life Cycle Of Autos
As the plants get closer to the harvest date of 10 weeks, it is wise to encourage the plants to use up their nutrient reserve. The final two weeks are known as the flushing period, meaning that the plants will use up their reserve amounts of N-P-K and trace elements. It is normal to see deficiencies begin to form as this is a good sign the excess nutrients are being used up. The calyx of the bud will now bulge and swell with a round and pointy appearance. Trichome development will be at the peak maximum and now is a good time to start checking the maturity of your trichomes.
Here at Fast Buds we pride ourselves on producing the fastest flowering autos on the market. Our strains will range between 9-10 weeks, which is extremely quick making them perfect for commercial growers, including novice to expert.
The buds will begin to fatten up and show signs of swelling up, with a prolific resin production. During weeks 8 is when the plants will be fed their last nutrient solution, as they will now be responsible for using up their reserve nutrients that have been stored over the duration of the plant’s life cycle. The plant’s appearance will look chunky, heavy, and full of weight with tightly packed sugar leaves surrounding the buds.
So, to answer your question—how long do autoflowers really take—look at the distribution of dots on the infographic. Please note that the baseline (‘0’) is what a particular breeder promises. And you can mouseover on a dot to glean some more info.
This wasn’t always the case. Just a few years ago, it was a common complaint on forums that an autoflower keeps growing. Obviously, the expression of ruderalis genes in such a plant was too weak, so it wouldn’t flower at 24/0 or 20/4. Sometimes, even a 18/6 light cycle was too much. People were advised to switch to something like 16/8, 14/10, or even 12/12. There’s even a term for this type of plants — superautos. Superautos tend to be big and high-yielding, but take forever if you treat them like normal autos. Today’s breeders do their best to create autoflowering varieties that never require any changes in light schedule.
Let’s start with traditional cannabis strains. They are short-day plants, aka photoperiodic, or simply photoperiod. If they grow naturally, photoperiod varieties only start to flower at the end of summer or at the beginning of fall—when the days become short enough.
Interpreting the Results
Or, if you’re new to the game, let’s take a look at what makes an autoflower seed to harvest time so short.
When planning how many weeks for autoflower you’ll need, take into account the following:
As you can see, these 4 breeders specify autoflower time from seed to harvest more or less realistically. Many growers really do cut down their plants within the given timeframe, and for others, their autoflower seed to harvest time is even shorter. Nevertheless, there are many instances where growers had to wait several weeks longer.
In indoor setups, the flowering begins only if you set your timer to 12 hours of day and 12 hours of night (12/12). And if the days are longer (e.g. 18/6), cannabis just keeps on growing and no flowering happens.