funsocaltiger

Even though the directions usually tell you to put the spikes 3-6' or something away from the base, I have heard of people using these spikes in containers without any problems for bananas. Jobes does have a spike which has a higher potassium count if you look around and they have a good assortment where you are buying.

Personally, though, I just use slow release Osmocote or similar (Dynamite, MiracleGro) that is a balanced 1:1:1 ratio. No problems there and it is cheaper per lbs for the concentration you getting in general compared to spikes. It'd be nice to find a higher potash ratio slow release but I haven't seen anything myself since most things have more nitrogen if anything.

Laurence