Pentas Water Use and Growth in Simulated Landscapes as Affected by Municipal Compost and Mined Field Clay Soil Amendments
Pentas lanceolata Schum. ‘New Look Red’ plants were grown in compost-amended, mined field clay-amended, or unamended sand soils in drainage lysimeters to evaluate growth, aesthetic quality, and irrigation requirements. Treatments were evaluated with irrigation controlled by tensiometers set to irrigate back to near field capacity when plant-available water in each soil declined to 50%. Compost-amended soils had greater (P < 0.05) mean shoot dry weight, total biomass, shoot-to-root ratios, growth indices, and landscape quality than other amendment treatments. Unamended soils and clay-amended treatments were comparable for all plant parameters. Total irrigation volumes applied were similar among treatments. Compost-amended soils yielded larger canopies, improved quality, and tended toward less cumulative irrigation. Clay amendment was not beneficial.