I don't know whether to fix or harvest this gal, All her leaves look like this even after a week of DM Saturater, liquid light, and spray n grow. 4 different plants with 4 diff nute issues, all raised together and treated the same. WTF?!
It is normal for the leaves to yellow and fall off in flowering. This is completely normal. The yellowing usually begins at the bottom leaves and works its way up. This is because the plant is no longer needing those leaves and is using the chemicals in these leaves to make other chemicals to make into THC. Its like a little factory more or less. Some strains yellow more than others depending on what nutrients you're using. My plants grown in soil seem to yellow a little more than the plants I grow in hydroponics. Take a look at my gallery. I have plants in week 5 of flowering and you can see that the leaves are quite yellow compared to the leaves of my plants vegging. How marijuana grows is it stores up nutrients in the leaves during vegetation. That is why you use nutes with a high nitrogen content during veg and when you switch the lighting over to 12/12 the fertilizers usually have lower levels of nitrogen. You don't want to give the plant lot's of nitrogen during budding because it will be real leafy instead of growing dense buds which is what you want it to do. When the lights are switched to 12/12 it signals to the plant that its life cycle is coming to an end and the plant will begin cannabalizing itself for every bit of available nutrition to make into buds and the plant does this by consuming the leaves it made during the time it was vegging. It is easier for the plant to use the nutrients stored in the leaves then to make new nutrients from the soil if that makes sense. The plant knows what it is doing and at first when i saw this happening i didn't know what was going on either but then i began to read a few really good posts online on this subject and i figured it out. Now i cut off as few leaves as possible and the yields im getting are great.
