Is this a trimming from a plant with these symptoms, or are you trying to root the clone in water? (doesn't work that way with cannabis) Are you planning to grow in a peat-based soil, or hydroponics?
If you need help through the cloning process, just let us know. But there's a couple (of hundred) posts here describing the techniques, which you can find using the CanCom search function. I think there's a sticky on the subject, too.

Systemic overwatering (consistent overwatering) of a normally healthy plant will develop those blotches. I believe it's the plants trying to uptake all that moisture with no place to vent it, and either it tries to store the moisture in the leaf cells, or swells tissues and blocks the gas exchange. (clogs the stoma) The cells burst under the pressure, causing necrotic spots. Root rot is the common result, as ther roots can not properly function if saturated.

At least that's my take on the situation. I sure wish I paid more attention in biology classes though, lol.

Looks like it was a very nice sativa. :thumbsup:
Rusty Trichome Reviewed by Rusty Trichome on . Black patches hello, I need to know the possible explanation for Black spots or patch to occure is it fungus, virus, or pests???? this picture is a clone from mother plant has same proplem the question here what is a black spot means, on the clone the patch is spreading and detoriorating the leaves gradually and not stopping even after cutting and isolatated from the mother. I need ecperienced explanantion for the possibilities the picture just an example for the eye to see what would look like Rating: 5