I've heard about using blackstrap unsulphered molasses the last 3 weeks of flowering to increase potency and taste and to stop using ferts until harvest. So I've been doing a little research and I find molasses is a great source of calcium and iron. Not only that but a good source of potassium, magnesium, copper, and manganese. So my question is why just use it the last 3weeks of flowering and not the whole flowering period.. Or even veg and flowering,
Along with regular nutes the whole grow just dont use as much molasses, until late flowering?
I dont know someone help me out here, maybe im missing something..
The reason has to do with the microbes in the soil. Microbes consume the nitrogen, the most important nutrient for veg. growth, and in the process they convert it to a form that the plants roots can uptake. Without this conversion the plants cannot consume the nitrogen in the soil. So, when you introduce a different source of food for the microbes, the sugars in the molasses, they go for the sugars and stop processing the nitrogen in the soil. This leads to nitrogen deficiency in the plant.
Now, molasses DOES have a lot of other useful aspects and I am using it throughout veg. and flowering. But, I add more nutes (nitrogen only) when I feed with molasses. So far this seems to be working, basically I am giving the microbes a larger food source and I haven't seen any issues with nute def. But, definitely use less molasses than you would in flowering, because in flowering the plants stop up taking nitrogen from the soil and start pulling it from their leaves.
edit: I use a fish based liquid fert. which is mainly straight nitrogen and is in a form that the plants roots can consume without being broken down by the microbes.
Edited by Bud Upinsmoke, 28 September 2011 - 06:38 PM.