Answer: It sounds as if you are doing the right things. Phosphorous does not move as readily through the soil as does nitrogen, so that might be part of the reason why you had abundant foliage (which nitrogen produces) but not an enormous amount of berries (which phosphorous promotes). Organic phosphorous sources such as bone meal usually have a lower percentage of total phosphorous than the chemical fertilizers, such as ammonium phosphate at 16-20-0, just to give an example. If you prefer organic sources, scratch the phosphorous down into the soil taking care to stay a few inches away from the roots. Or, you might want to try Miracle-Gro, which is 15-30-15. Water well before and after applying any fertilizer. Bittersweet benefits from a late winter/early spring pruning of old wood. I hope this info helps!
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