by Nebula Haze
Why isn't my weed plant growing buds? How do I get it to start flowering?
Short Answer: Cannabis plants only make buds when they are female and in the flowering stage of life. Otherwise, cannabis plants don't make buds.
To get cannabis to start making buds:
- Most plants must be at least 3-4 weeks old before they will start flowering
- Make sure the plant is female by looking at the preflowers
- Initiate the flowering stage by giving plants 12 hours of complete darkness every night. Most indoor growers accomplish this by putting grow lights on a timer with a 12/12 schedule, while outdoor growers typically wait for the nights to naturally become long as summer goes on (which initiates the flowering stage naturally)
- Buds should start forming in 1-3 weeks as long as the plant is getting uninterrupted darkness for 12 hours every night.
Cannabis plants do not start making sex-specific parts like buds until they reach the "flowering stage" of life. If your cannabis plant is growing without making buds, it means that it's still in the "vegetative" stage of life, or the cannabis plant isn't female.
Vegetative Stage – "Child" stage – plant grows just stems and leaves with no buds
Flowering Stage – "Adult" stage – plants starts growing sex-specific features like buds or pollen sacs.
Whether growing indoors or outdoors, the stage of your cannabis plant is usually determined by light schedules.
So before cannnabis plants start flowering, they are in the vegetative stage which means the plants only grow leaves and stems, with no buds like this:
First stage of Life – Vegetative Stage
(grows only leaves & stems – no buds)
A grower can tell when the vegetative stage has ended because the plant starts growing gender-specific parts in addition to leaves and vegetative growth.
In the second stage of life, the flowering stage, female cannabis plants will start to make buds (flowers). Male cannabis plants will only make pollen sacs (no buds) and are usually discarded by growers.
Second stage of Life – Flowering Stage
(plants start growing gender-specific parts like buds and pollen sacs)
Most growers only nurture and keep only female cannabis plants, since female plants produce buds that contain high levels of THC and other cannabinoids.
Male cannabis plants do not produce buds, only pollen sacs, and can also pollinate your female plants (which reduces yields and causes buds to have seeds), so most growers get rid of male cannabis plants immediately.
Cannabis plants grown outdoors will naturally enter the flowering stage in the fall as the days start getting shorter.
When growing cannabis plants indoors, the grower usually needs to artificially change the light schedule to get plants to start flowering (producing buds).
There's an exception!
The exception to this rule about light schedules is auto-flowering (ruderalis) strains of cannabis, which will automatically start flowering on their own regardless of what light schedule they're kept under. Most auto-flowering plants start making buds around 3-4 weeks after germination, though some strains take a little longer.
Cannabis Light Schedules (What Makes Cannabis Plants Start Producing Buds?)
Auto-Flowering vs Photoperiod Strains (Autos don't care about light schedules)