Influence of Planting Depth and Mulch on the Growth of Nine Species of Ornamental Plants in Landscape and Container Settings
Six different planting depths and mulch treatments were applied to nine different species of landscape plants in a field study beginning July 5, 2001. Plants were maintained for a two-year study period on the effects of improper planting depths and mulch on the following species; Southern Magnolia Little Gem (Magnolia grandiflora), Bald Cypress (Taxodium distichum), Crape Myrtle (Lagerstromia indica x fauriei Natchez), Azalea (Rhododendron indicum George L. Tabor), Indian Hawthorn (Raphiolepis indica Clara), Loropetalum (Loropetalum chinense Burgundy), Dwarf Gardenia (Gardenia jasminoides Radicans), Dwarf Nandina (Nandina domestica Fire power), and Liriope (Liriope muscari Big Blue). Four growth indexes, and quality ratings were collected over this study. A second experiment was conducted on the same plant species in a container study that involved three different planting depths. Growth index measurements were taken four times over an eight-month period, and shoot and root dry weights were also collected. This research will help to determine the tolerances of these nine species to improper planting techniques and mulch. For this study the following planting depths were used in the field were 7.6 cm above grade, 3.8 cm above grade, at grade, 3.8 cm below grade and 7.6 cm below grade. One half of the plants in the field were mulched at a rate of three-inches with 5/8th screen pine bark mulch. In the container study the following planting depths were used: at grade, 3.8 cm below grade, 7.6 cm below grade.
For all species, growth did not differ among the planting depth treatments in the field. However, there was a significant affect by the application of mulch on seven of the eight species in the field study. In the container study, significant affect of planting depth was observed in all species except bald cypress, Indian hawthorn, and dwarf gardenia.
Advisor:Edward W. Bush; Charles E. Johnson; Allen D. Owings; Paul W. Wilson; Clinton P. Hegwood
School:Louisiana State University in Shreveport
School Location:USA - Louisiana
Source Type:Master's Thesis
Date of Publication:09/14/2004