Hazelnut Shells Are an Effective Mulch Product for Container Nursery Production

Hazelnut shells, byproducts of nut crop processing, could be used as a regional or locally sourced mulch for container nursery production. This study evaluated the effectiveness of hybrid hazelnut shells as mulch in container plant production by comparing them to four other mulch treatments: control (no mulch), rice hulls, bark, and sawdust. Pots were filled with a commercial substrate, planted with petunias [ Petunia × hybrida Hook. (Regel)], and inoculated with ryegrass and white clover. Substrate moisture, substrate temperature, surface temperature, weed emergence, and plant growth were monitored over a 30-day period. Data were analyzed using analysis of variance and Tukey’s honestly significant difference for mean separation (α = 0.05). Compared with commonly used mulch materials, hazelnut husks were as effective as, or superior to, conventional materials at suppressing weed emergence while maintaining moisture and temperature and supporting plant growth.