How many marijuana plants under a light

A question I get a lot is how many plants do I use under a light?

What I usually do is 1x 600watt per square meter, which can house around 16 to 25 plants. Any other suggestions?


I only put 1 plant per 4 SF. So; In a 4’x4’ tent; I only grow 4-5 plants.

This could be different for clone set ups, such as SOG.

It all depends on what form of growing you are using, Strains grown, and whether from cuttings or seeds.

This question should really be: “How much coverage do I get from different size HID lamps?”

250 watt = 2’x 3’
400 watt = 4’x 4’
600 watt = 6’x 8’
1000 watt = 8’x 8’


Keep in mind that this is an HID measure.

LED might be different. We are doing some LED trials now. I will ipdate this, but I feel the footprint is much different between HID and LED.