ed: Once a month ammonium sulfate or a little Osmocote is enough if they are growing fast enough. Mine are actually growing too fast after they get some size so I'm trying to slow them down. I may cut off fertilizer for several months on the plants more than a year old. My Sweetcrisp in a 10 gal pot that I've had 22 months is 5ft tall and almost as wide. It could have 8-10 lbs fruit this year. I've already applied a little Osmocote. That may be all it gets all year. How did yours grow last year?

If you are wanting to use the shotgun approach, here's what I would suggest: Use either Miracle Grow's all purpose continuous release plant food (shake 'n feed with the yellow cap) or Gertens acid loving plant fert. Apply one or the other early in the season after leaves are out. Both are controlled release and will fertilizer for an extended time. Were it me, I'd apply at 1/2 of the rate suggested on the label. BB's don't require a lot of fert (adapted to low fertility soils), and there is a good chance your soil has plenty of P & K already. Then, on a weekly or bi-weekly basis, starting a few weeks later, disolve 1/8th or less of a teaspoon of Ammonium Sulfate per gallon of water, and water the root zone of the plant. That is about 1/2 the concentration rate I typically apply (I use just under 1/4 tsp per gallon), but that is to compensate for the nitrogen already in the controlled release ferts. Cut off the Ammonium Sulfate by the middle or end of July, earlier if you get frost in August. The application of Ammonium Sulfate will push rapid growth, and apply sulfur to continue to keep the pH down. However, if your pH gets too low, you should stop the Ammonium Sulfate application, or switch to urea as your nitrogen source. Avoid nitrogen sources that are nitrate based. I didn't suggest Osmocote as a controlled release fert as approximately 1/2 of the nitrogen is nitrate based, rather than ammonical. People have used it without apparent deleterious effects, but there are better alternatives out there with less nitrates. Water well periodically to ensure salts from a potential over-application of ferts have a chance to be flushed past the root zone. This post was edited by charina on Fri, May 30, 14 at 16:38

Karin, Im not sure cottonseed is the best fertilizer, you picked it because its acidic and organic I presume. But those granular organics, Im not sure the break down and their nutrients become readily available in potting soil. Thats why I add garden soil and or organic fertilzer with live cultures in it. The fungus and bacteria should help process the fertilizer. Maybe sprinkle some compost on top of the cottonseed to innoculate. Also in the winter I doubt it will make any progress on breaking down and becoming available due to the cold soil. The only thing I was able to ever grow blues with is a cheap chemical acid plant food. Its the only thing that would work for plants in the ground here, and so I use it on my new potted blues too. My water is alkaline and my soil is stubborn and neutral ph. I recommend getting soil sulfur and iron phosphate to use also. Probably fertilize your plants twice a year, maybe Feb/March and June/July

You can check out some "before" pics here :) Please note that the before pics were taken in March, 5 months after overseeding and the grass didn't have the chance to fully grow. The "after" pics that I'm posting right now were taken in September, I believe. I went organic right at the beginning of my journey with lawn care and I've never really used chemical fertilizers. I don't live in the US, actually. I'm Polish and I order my SBM and alfalfa pellets online. $15 for a 30 kg (65 lbs) bag + $5 shipping, next day right at my doorstep :) However, I can't find corn gluten meal anywhere here in Poland! Now, not to hijack my own thread, is there anyone who can help me with my original question?