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how much light to grow marijuana

How much light to grow marijuana

Indoors most growers put their plants on a 12-12 schedule to initiate flowering. Outdoors the plant will naturally start budding in late summer when nights are growing longer and longer as winter approaches. Just make sure plants aren't exposed to light during their dark period!

In optimal conditions if height and space is not an issue, you would probably want to vegetate your cannabis plant for 60 days or more before switching it over to flowering. This gives your plant plenty of time to grow big (so you get bigger yields), and allows new growers to dial in their grow before plants enter the sensitive flowering stage. In the vegetative stage, it is easy to recover from problems, but problems are a lot more serious in the flowering stage, where mistakes can dramatically hurt your final yields.

What is 12-12 Lighting?

So indoor growers have a choice to flower their plants whenever they want… When is the best t ime to start flowering your cannabis indoors?

While not technically a "stage," all grows start with cannabis seeds or clones.

If you're growing cannabis outdoors with seeds, you should wait until a few weeks after the spring equinox to put your seeds outside. In the northern hemisphere this means seeds go outside in-or-after April, In the southern hemisphere seeds go outside in-or-after October.

Most indoor growers provide 18-24 hours of light a day (known as 18-6 or 24-0 light schedules). Giving your cannabis plants more hours of light each day in the flowering stage will encourage faster growth.

Short nights keep cannabis plants in the vegetative stage. You can keep a cannabis plant in the vegetative stage for basically forever as long as the plant continues to get short nights (shorter than 1s-12 hours, depending on the strain).

Outdoor growers wait until their cannabis plants start naturally flowering on their own, usually after mid-summer when days start getting shorter than 12 hours.

How much light to grow marijuana

LED grow lights are very popular among cannabis growers as an alternative to HPS grow lights. They tend to run cooler and also usually come with built-in cooling. They can often be plugged into a wall and simply hung over plants which is definitely easier than setting up an HID grow light. LEDs also have great penetration so they don’t need to be moved frequently like fluorescents.

3 Main Classes of Marijuana Grow Lights

Pros of Fluorescents

“LEC” and “CMH” both refer to Ceramic Metal Halide grow lights, which is a type of HID light that is a bit more efficient than a regular Metal Halide light

CFL Grow Lights

High Pressure Sodium (HPS) Grow Lights

T5 grow lights are one of the most easily available types of grow lights and are used to grow many different types of plants. As a result, they’re available in many garden and home improvement stores.

These cannabis plants are thriving under T5 grow lights

HIDs are very well suited to growing cannabis and very easy to use once they’re set up. If your main goal is to get the highest yields possible, then HIDs are the way to go! However, they do require extra setup compared to the other grow lights because chances are you will need a fan to vent out heat from your grow space.