The problem I had with it was twofold. The first part of the problem was with the soil composition itself. After a few waterings, the soil became compacted and tight. This led to poor drainage as the soil held too much water. The compacted soil also didn't allow for enough oxygen to penetrate the root zone, which was only exacerbated by the excess water it was holding. The result was that the plants regularly showed symptoms of overwatering even though I was allowing enough time for the soil to dry out between waterings.
The second part of the problem had to do with the MG nutes they pack into their soil. I read the bag and understood that no additional nutes were required for the first 3 months of use. However, after the first 3 weeks or so, the plants started showing signs of nitrogen deficiency which got worse by the day. To correct the problem, I treated the plants with a diluted concentration of MG nutes. This is where things got ugly. Within about 24 hours, the nitrogen deficiency started to improve and I thought all was well. But the next day, the plants began showing signs of nute burn. The blast of MG had corrected the nitrogen deficiency, but in the process it lead to excessive amounts of the other nutritional components, resulting in nute burn. Over the next two weeks or so, I tried correcting the problems by flushing it with plain water which only resulted in the nitrogen deficiency returning as well as returning symptoms of overwatering because of the poor drainage. I went back and forth between the nitrogen deficiency, secondary nute burn, and excess water build-up until finally my plants had enough and died.
Now, if all of this happened to me today it would be a different story. Knowing about the poor drainage, I would cut the soil mix with additional perlite. Because I now know that to treat a nutrient deficiency you supplement the plants with only the deficient nutrient, I would give them a shot of Nitrex at the first signs of a nitrogen deficiency, rather than feed the plant a light dose of MG. Basically, the problems I had and the mistakes I made are common to new growers and not the fault of Miracle Grow, per se. However, I also have to acknowledge that I wouldn't have had any of those problems had I not chosen to use the MG soil and nutes. And the fact that the nutes packed into their soil do not provide a sufficiently balanced diet for the plants makes it that much more difficult for new users to have success with it. I would have been better off using a soil mix that provided better drainage and had no chemical nutes pre-loaded. And that's what it comes down to. For new users with limited experience, I don't believe that it is a suitable choice for growing marijuana.
