the place we bought has red lava rock for a yard. it is pretty good, but the plastic sheeting underneath had rotted away mostly, where necessary i remove it and paly down sand. all my gardening will be raised beds and troughs as the soil in our area of the PNW is reputed to have high arsenic levels (some believe this is why there is such a high level of MS here...) the beds will be placed as level as i can over the lava rock...