Good question.
A friend used Osmocote for years and had extremely happy results.
What I would do:
Dig a wide(at least three feet) shallow hole in an area with a lot of dead leaves/grass covering the soil. pull the leaves to the side before digging.
Once the soil is broken up, add Osmocote to the soil and turn again.
Plant a clone and then sprinkle more Osmocote in a ring around the plant, at least a foot away. Make this band about two feet wide.
Pull the leaves and grass back over the disturbed soil and water.
Come back when the plants should be done.
This should only be done where regular summer rains occur. It won't work where I live. We have up to seven months without rain, in central Cali.
The friend I spoke of used inner tubes and 30 gallon peat pots, loosely tied to trees hanging over a local stream, and floating with a few inches of peat pot in the water. He'd check them monthly, while fishing.
This system works beautifully, once mastered. Ever seen a boat full of buds?