Submitted to: Southern Nursery Association Research Conference
Publication Type: Proceedings
Publication Acceptance Date: 8/1/2004
Publication Date: 8/1/2004
Citation: Fain, G.B., Paridon, K.L. 2004. Production of bareroot ophiopogon japonicus using calcined clay as a growth substrate. Southern Nursery Association Research Conference. 49:313-316
Interpretive Summary: Many groundcover plants such as mondo grass are marketed and sold as bare root divisions. Barerooting requires the removal of the potting media from the roots. This can be a difficult and labor intensive process especially with organic media. Mondo grass was grown in various substrates including calcined clay. Time required to bareroot and total plant production was determined for each media. It took more time to bareroot plants grown in organic media compared to those grown in calcined clay. Plants grown in calcined clay yielded more divisions on average than any other media. The results of this study indicate that mondo grass grown in calcined clay produce higher quality bibbs than those grown in more standard nursery media with a significant decrease in labor needed to harvest in bareroot production.
Technical Abstract: Ophiopogon japonicus are often marketed and sold as bare root divisions. Barerooting requires the removal of the growth substrate. This can be a difficult labor intensive process and can be destructive to the roots especially with organic container substrates. Profile is a calcined clay product whose base minerals are illite clay and amorphous silica. The raw product is heated in a kiln at 1500C+, which permanently changes the base minerals to a stable calcined clay (also called porous ceramic) particle. These products have been used for many years as soil amendments in golf course greens to improve soil structure. On February 23, 2003, 3 bare root single bibb divisions of Ophiopogon japonicus and Ophiopogon japonicus 'Nana' were potted into 8' wide by 5-1/8' tall containers using either 100% aged pinebark, 8:2 (v:v) pinebark:peatmoss, 100% perlite, 100% 24x48 Profile (P1) porous ceramic or 100% 5x50 Profile (P2) porous ceramic. Hardware cloth was placed in the bottom of each container to prevent loss of substrate through container holes. On September 24, 2003, four workers were randomly assigned two replications of Ophiopogon japonicus from each treatment and instructed to bareroot each container by washing the substrate from the root system using pressurized water. The time required to bareroot each container was recorded. Bibbs were subsequently divided and graded into #1, #2 and #3 grades based on density of foliage and roots. The Ophiopogon japonicus 'Nana' were overwintered and harvested as described above on July 14, 2004. At approximately 210 days after initial potting, the Ophiopogon japonicus were harvested as described. By nursery standards these containers would not have been considered full at the time of harvest. It took approximately 61% more time to bareroot plants grown in pinebark compared to those grown in P1. Plants grown in P1 yielded 52% more bibbs on average than any other substrate. On March 12, 2004 the Ophiopogon japonicus 'Nana' were harvested. It took approximately 81% more time to harvest plants grown in pinebark than those grown in P1. There was no difference in total bibb yield in plants grown in P1 compared to pinebark or pinebark:peat substrates. Plants grown in P1 did yield 210% more #1 bibbs than pinebark:peat and 60% more #2 bibbs than pinebark. The results of this study indicate that Ophiopogon japonicus grown in P1 produce higher quality bibbs than those grown in more standard nursery substrates with a significant decrease in time to harvest for bareroot production.