Lights in greenhouse?

I'm growing medicine in my greenhouse and have 4 sativas that are about 4 1/2 feet tall and have been flowering for about 4 weeks and three younger plants (BB and RHS) about 2 feet tall just beginning to flower. They're all in soil in containers rather than in the ground. They've been staying really healthy with just normal sunlight and feeding but now that the weather is changing I'm concerned about them. I've been putting heat on at night for them but after a beautiful sunny start to the fall, it's now getting cloudy here in the Pacific NorthWET and I'm worried that they may need lights. Is natural light enough even if there is no sun or do I need to supplement? I've been gardening since I was a child and usually observe my plants to see what they need, but I don't want to wait til they shows signs of stress if they need supplemental light.

Thanx,
Granny
USDA Zone 8
Sunset Zone 6

they won't show 'stress' over needing more light, they just will slow down in their growth, and produce less ... if you do add lights, it can only help the growth ... be sure to maintain them at 12 hours duration for flowering ... :smokin:

hmmm...slowing down will definitely cause *me* stress ! However, I think these plants will still yield enough for those needing the medicine. My main concern is I have to have them ready by mid-December. This is one of the 4 older Sativas.

my guess is another 4-6 weeks, looking at it ... that particular 'sativa' is a sativa-dominant hybrid, by the way, (partially indica) ... looking very healthy ... :thumbsup:

Thank you, roadcam! I was given 3 young indica (so I was told) plants early summer (am harvesting the last few buds from them now) and I could see a clear difference between those and the new ones so I made the assumption that the 4 were Sativa. I grew them from seed that was given to me so don't know the parent plants. My other 3 younger plants are purchased seed and they are supposed to be Red Hair Skunk and Big Bud.

I haven't decided yet what to do about lights. I have some fluor. but not enough to cover all the plants and not sure I want to buy any more right now. But maybe I'll use what I have on the sides, some extra light is better than none, eh?

yes, it might be a good idea to stuff some fluoros just below the canopy, to light up the branches under the main cola, might be your best use of a limited amount of lamps ... :smokin: