A mechanical device including two concentric space frame structures is used to enhance plant growth. Essentially identical in shape but with the inner space frame smaller than the outer by a 4:5 relationship the space frame structures independently rotate about a common axes line. Each space frame consists of a right square pyramid of rods with its apex pointing upward and a second similar pyramid directly below it by a distance approximately two and one half times the length of each rod comprising the pyramid. The second, lower pyramid however has its apex pointing downward and is turned 45-degrees about a line connecting the two apex points. Eight additional rods complete each space frame. They each, respectively connect a corner of the upper pyramid base to a corner of the lower pyramid base in a manner that is symmetric.