Abstract: An experiment was conducted to determine the suitability of mulches made from Eucalyptus cladocalyx trimmings for the establishment of young California sycamore (Platanus racemosa) trees and whether composting reduced any phytotoxicity symptoms that might be associated with fresh E. cladocalyx. The mulches prepared from fresh and composted E. cladocalyx prevented the growth of annual weeds, increased soil moisture retention, reduced diffusive resistance of California sycamore and increased stem diameter compared to unmulched sycamores. The root length of sycamores was higher in soil profiles under mulched trees than in soil under unmulched ones. E. cladocalyx mulches reflected more photosynthetically active radiation and maintained lower surface temperature than biosolids mulch or unmulched soils. Both freshly chopped and composted eucalyptus branches were effective in promoting growth of sycamore.