A question..

I dont know if this is a common observation, but I experience that if I put freshly cut clones directly under a high wattage light, they will die immediately. If I put them in darkness they will flower and root slowly. Apparently somewhere in between is better for most strains.


What is the most common light regime, light intensity and spectre used by professionals when rooting cannabis clones?



Im sorry if the question is phrased in a way that makes it difficult to answer, thank you for replies.

arcticsun said:

I dont know if this is a common observation, but I experience that if I put freshly cut clones directly under a high wattage light, they will die immediately. If I put them in darkness they will flower and root slowly. Apparently somewhere in between is better for most strains.

Click to expand...

I might be able to add some light (lol pun) on part of your question. The cuttings in full light are trying to grow without any support from the lack of a root system so they can't replenish there H20 and nutes fast enough . when rooting reguler plants(or it would be the same for Pot) in a greenhouse we used a Misting Table it had bottom heat and it was on a timer set to spray a fine mist of water every 5 mins for a sec during the day...This info might help a little bit.I bow to the regulars.

Very little light for the first 7-10 days...until they get a good root system going. Some people clone in darkness.

Common florescent shop lights on 24/7 until you get roots has never failed me yet. I use a 2 foot 2 bulb fixture that hangs a couple of inches above the dome.

how much high wattage are you talking about Articsun??
I use a 250 mh....2 feet above the clones and 5 days later ive usually got some roots...
if you have to many leaves and you put to much light that might cause some problems as the stem cant get the leaves enough water so the thing ends up keeling over....so many variables....and what are you cloning in?

This is a question that came up in chat the other day, it turned out some rooted in darkness and others tried to give as much light as possible, there was no consensus as to which method was most efficient. Im sorry if this is the wrong forum for this discussion.


My approach has been for years to use common fluorescent lights under 24/7, but I heard of people rooting without lights so i was wondering if I could find some info on how the pro's do it and most importantly why is the one more efficient then the other. Normally I clone in a room that holds a temperature of 25 degrees centigrade and a high rh %, I try to transplant my cuts directly into soil as quickly as possible after they are cut off the mom.


Seems to me that the pain threshold for light for most my cuts are at about 250w at 50 centimeters distance from the cuts. It also seems to me that the more light the cuts are given, within their pain threshold, the faster they will root. Now this is only my subjective perspective. Has there been done any research or is there any scientific reasoning for rooting in darkness?



Thank you all for your replies.