I bought a liquid 5-1-1 fertilizer and it says mix 1Tbsl per gallon for container plants. This is a dumb question, but is it like 2 cycle oil? Even though one plant is not going to get a gallon of water, it will still get the correct amount of nutrients right? It was the closest to the 5-1-3 ratio I could find.
I think it will get all the fertilizer it need from that - I don't think many could make up a gallon of water and give it to a plant ensuring none drained out and the whole rootball got saturated. If you are concerned about the volume, perhaps you could cut the dose in half, and the water also?