I have a Ross root feeder that I absolutely love. It saves money on water but hate paying the cost of the "spikes" for fertilizer. The spikes for the trees are 25-10-10 and so is the fertilizer I picked up at the ag depot that sells it in bulk quantities. Can I use bulk fertilizer for the trees as well? I don't think it will pass through the small holes in the feeder, unless it dissolves. What about crushing the pellets into a powder ?

I did check Home Depot and they are way less expensive than the garden store, but now I have all this fertilizer!!!!

Any experience or success with this?