Root Zone Management of Greenhouse-Grown Succulents

Succulent plants are an increasingly popular product sector for greenhouse and nursery growers.  Very little information has been published on the culture of these plants and almost all information available to growers is anecdotal.  Our objective determining the effects of root zone management factors on the efficiency of growing and finishing plants for market.  Taxa included Aeonium ‘Zwartkop’, Agave ‘Blue Glow’, Aloe ‘Fire Ranch’, Echeveria ‘Afterglow’, and Senecio cephalophorus ‘Blazin’ Glory’.  Three independent studies measured growth response to a range of fertilizer rates (0, 50, 100, and 200 mg^.L^-1N from 15N-2.2P-12.5K water soluble fertilizer; 2) three substrate moisture levels ( maintained at  10%, 20%, and 30% volumetric water content as measured by a time domain reflectometry meter) and 3) five growing substrates (bark, commercial bark and peat mix, commercial peat mix, and a wood chip/peat mix)  Parameters measured included plant height, width, root and shoot dry weights as well as overall appearance/marketability of plants. Among fertilizer rates, the higher rates  produced larger, more marketable plants across all species. The 10% volumetric water content (driest) resulted in the smallest plants.  The substrates with peat produced the largest plants; the bark and bark/slate aggregate mix the smallest.