So the original soil was topsoil and compost from a local landscaper. Has had plants growing in it for about 6 years and I envision burying stuff in the soil instead of putting it in the compost heap. Have a permanent herb bed at one end, mix of vegies throughout the rest. Very few chemical fertilizers in the soil - mostly fish emulsion or organic. Beds are waist-high and just go right into the ground. So I am thinking some kind of earthworm would be best, rather than the red ones that are used for vermiculture, or am I wrong?