ROOTING OF EVERGREEN STEM CUTTINGS IN DIFFERENT SUBSTRATES

          Terminal stem cuttings of three evergreen species: Thuja plicata, Chamaecyparis pisifera ‘Boulevard’ and Juniperus chinensis ‘Hetzii’ were rooted under greenhouse, basal heating and mist conditions in four different rooting substrates: perlite, sand + perlite (2:1), sand + leaf compost (2:1) and peat + perlite (2:1). Cuttings were taken at 03.11.1999 and 27.03 2000 and treated with IBA 2000 ppm and Atonik.
Rooting performances were expressed in terms of rooting percentage, average root number per rooted cutting and length of roots per cutting. Chamaecyparis pisifera ‘Boulevard’ and Juniperus chinensis ‘Hetzii’ rooted better in the sand + leaf compost while, Thuja plicata in sand + perlite.
Sand + perlite substrate was beneficial for increasing root number of Thuja plicata and perlite for Chamaecyparis pisifera ‘Boulevard’ and Juniperus chinensis ‘Hetzii’. Roots length reached the highest value on Chamaecyparis pisifera ‘Boulevard’ and Juniperus chinensis ‘Hetzii’ with perlite rooting substrate and on Thuja plicata using peat + perlite substrate.
The most beneficial effect on rooting percentage was obtained with IBA 2000 ppm treatment.
Autumn cuttings were favorable for Thuja plicata and the spring ones, for Chamaecyparis pisifera ‘Boulevard’ and Juniperus chinensis ‘Hetzii’ with all the rooting substrates.