Carnation growers utilize any of several bulky organic materials for amending greenhouse soils to improve aeration, drainage, and moisture retention. Redwood sawdust has been the standard material used in San Diego County. The trial reported here compared plant growth and flower production of carnations grown with two soil amendments—10 and 20% by volume of Redwood sawdust, and 10 and 20% by volume of processed lignin particles, replicated three times. They were conducted at Hillside Floral Company, Encinitas, and the amendents were incorporated in a Carlsbad sandy loam in raised benches prior to planting. The greenhouse soil had not been previously amended.

The processed lignin amendment used in these tests is a product of the Loamite Division of Pope and Talbot Corporation.