Full sun too strong?


I’ve been growing 5 different strains outdoors, in full sun for most of the day. I noticed that 45,000 to 70,000 lux is optimal for flowering. Above 70,000 lux is likely to light burn some indicas. I just measured full sun and I see it is 117,000 lux. I wonder if a couple of my strains have crispy and crusty leaves because they got light burned? The other 3 strains have exactly the same pots, soil, watering, location, etc. and they have normal functional green leaves. The two that did not do well were Aurora Indica and Critical Kush. The healthy ones were Cotton Candy, Cookies Kush, and Blue Cheese: Much more sativa-like forms.

Should I get some mild shade cloth to keep the light down to 70,000 lux?



I don’t know where you are located: I’m in SoCal and have been growing Indica dominant strains like Og Kush, Gold Leaf, Sour Diesel, Jack Herer etc and they get full sun almost daily. No sign of light burn. If you are in the south it’s entirely possible that the light intensity is too much.


San Diego, but it shouldn’t be that different. I’ve seen some photos of Aurora Indica grown indoors and it looks completely different. Maybe I just got a weak clone.

I think maybe sativas grow in full sun in Mexico and Central America, while indicas grow in the tropical jungle with some shade. All my strains that did well have taller branching form that I associate with sative. The two that did poorly are very short and thickly leaved, a form I associate with indicas.


I believe that being able to survive intense sun and being able to thrive in it are two hugely different things. 2 of my 3 strains got burnt to a near crisp while one strain LOVED it.
I had to build emergency shade canopies for 7 of 8 plants.

I personally would shade them if they show any signs of deterioration.


Thanks so much for confirming this! I was looking at every plant disease and deficiency website trying to figure out what was wrong with those two strains. They are just about ready to harvest now but they certainly look pretty nasty. And throwing some shade cloth on my grow cage roof is so easy!

I’m in coastal San Diego, but we’re inland far enough to get some damn strong sun and we do get Santa Ana winds too.