Most field production of woody ornamental plants involves clean cultivation of rows, performed by either mechanical or chemical means. Grass cover has been shown to reduce erosion, but may have a detrimental effect on the growth and vigor of young trees. Clover cover has been shown to not adversely affect plant growth. The objective of this study was to compare the relative merits of three row covers, clean cultivated, pine bark mulch and kobe lespedeza clover, in combination with two irrigation rates, low and high, on field-grown red bud and crape myrtle plants.
Crape myrtle and red bud plants were tallest and had a larger caliper when grown with a clean row or with pine bark mulch. Kobe lespedeza clover reduced plant growth of both species when supplemental irrigation was not provided. Clover reduced plant height and caliper of red bud even when irrigated. Generally, plants grown under pine bark mulch were more efficient in water use as shown by greater stomatal conductance in August.