I have a rhubarb plant that hasn't done well in years past. It starts out good then insects start to eat the leaves and it dies back. Last fall I used 12-12-12 fertilizer and it is growing very well this year. It shot up three large stocks with seed flowers that I let go to see what would happen. The plant looks very healthy and large. Have I cured my problems by feeding it? When is the best time to cut the stems to make jam from it? The stems are green, not red, never did get red.