I have recently put few of my flowering plants into flower, and all the lower new growth start to turn yellow and die except for the top growth. the stalks of the lower new growths r pretty soft and i read that its lack of boron, or a bit too much? i flushed all the plants with Ph'd water, and c if its gonna turn fine. suggestions anybody?tons of my new growths have died so i had to cut them down, please help, thanx. lower new growths starts with yellowing and turning a bit brownish.leaves can turn grey, and the stalks become very soft.