Evaluation of green/pruning wastes compost and vermicompost, slumgum compost and their mixes as growing media for horticultural production

•The physicochemical parameters and GI ratios of GPC, GPV and SLC are determined.•Rosemary, lettuce and onion are plants sensitive to high compost dosages.•Leyland cypress and ornamental plants show good growth rates with 65% and 50% respectively of GPC dosage on substrates.•Leyland cypress growth is increased when 10% of slumgum compost is included as compared to the peat substrate.•25% GPV mixed with peat could be used as a growth medium for rosemary, Leyland cypress, lettuce, onion, petunia and pansy.

Three composts were used as plant growing media: green and pruning wastes compost (GPC) and vermicompost (GPV) and slumgum compost (SLC). Their main physico-chemical and biological characteristics were studied and nine growth substrates were prepared in order to establish production essays for rosemary, Leyland cypress, lettuce, onion, petunia, and pansy. GPC compost and GPV vermicompost had excellent physico-chemical characteristics, allowing them to be considered good substrates. The high E.C. and the low GI values for SLC means that it should not be used in high proportions. However, the high concentration of N could permit its use in suitable fertilizers, especially in Leyland cypress. Rosemary, lettuce and onion were seen the more sensitive species to high dosage of compost. Leyland cypress, petunia and pansies recorded good growth rates with high GPC dosage. Finally, GPV, at a proportion of 25% of the substrate, could be a good sustainable practice for plant production.