Date of Award


Degree Type


Degree Name

Departmental Honors


Plants, Soils, and Climate


Peat is the central component of the soil-less media mix in all greenhouse crop production but it is expensive because it is harvested in Canada and shipped to greenhouses across North America. Wood chips provide a local, low-cost alternative to peat, but observations by growers indicate potential growth reductions from the addition of wood to peat-based media. Here I report the effects of the addition of wood chips to peat-based media. The study included four treatments: two controls (peat/vermiculite: 50/50 and 75/25) and two treatments with wood chips ' (peat/wood chips: 50/50 and 75/25) with three species (sunflowers, soybeans, and cucumbers) in each treatment. All containers were maintained in identical conditions on a greenhouse bench with supplemental light. At harvest on day 26, dry mass, fresh mass, and leaf area were measured and comparative photographs were taken. There was no statistically significant difference between the 25% and 50% treatments, with either the wood or the vermiculite, but both the wood chip treatments reduced growth of all three species. Fresh mass with wood chips in sunflowers was 52% of the control, the cucumbers were 31 % of the controls, and the soybeans were 74% of the control. The detrimental effect of wood chips appears to vary with species.



Faculty Mentor

Bruce Bugbee

Departmental Honors Advisor

Corey Ransom