How many plants under light?


I’m going to try MH and HPS lights for this grow this year instead of CFL bulbs. I was thinking of getting on 600w light and have no idea how many plants I can do under it to get a good yield from them. I have 3 fem purple haze and 5 gold leaf seeds on the way from ILGM🙃

I have a green house so space is not an issue.

Thanks for the help in advance!


Hello there @Gizmo,

You’ll be fine with eight plants. If things go the way you want them to. But there is that one or two that may not make it. So that in mind, ya you’ll be fine. I had 10 under one400 watt HP’s. But now there under one 400 watt HP’s nd one 1000 watt HP’s still vegging.



I would say one of each for best yeilds but three would get you same amount of yeilds plus an ounce or so. And cost more and more time. More nutes more money.


Make them work for you . You not work for them.


I have 6 plants under my 600w MH right now. Could easily fit 8. I’m growing in a 5’x5’ tent.


It all depends on how big you grow to accept light lf you grow out bigger foliage before flower you dont need to add more plants. With the lights you have one plant grown to the right veg hight say 4 feet tall topped many times would yeild almost the same of all those plants. Remember if a plant can only accept 200w your 400w is going to waste…even 6 200w plants are only using 200w


Okay thanks for the help. I’ll start with all of them and I’m sure I’ll end up with a couple of males I’ll have to throw out so it should work out fine then. I’m gonna try so LST this grow to see how that works out for me. I’m excited!