GROWING MEDIA USED BY NURSERIES FOR CONTAINER-GROWN ORNAMENTAL PLANTS IN GIRONA (CATALONIA): A SURVEY OF 1996 AND 2009

Most of the ornamental plant nurseries in Catalonia are located in the Province of Girona in the north-eastern part of Catalonia. The estimated area of land devoted to growing ornamental plants in nurseries in 1996 was 900 ha, compared to the current area of 1600 ha. Based on information provided by business organizations and acquired from surveys of nurseries, the growing media most widely used in 1996 and today were identified and analysed. Changes have occurred in these growing media in terms of the nature of the components, how the growing media are made, and the properties and reproducibility of the mixtures. For example, forest litter and different fractions of fine sand were commonly used in 1996, but have since been replaced with peat moss, composted pine bark and smaller amounts of coconut fibre and trimming compost. In 1996, it was common to prepare growing media at the nursery using com¬ponents from the nursery itself, which meant that the mixtures were not standardized and were difficult to reproduce. Most nurseries currently use growing media supplied by specialized companies that are prepared based on standardized, reproducible formulas. The current trend is to use raw materials with a high degree of biostability to ensure the original properties of the growing medium are maintained during the entire growing period. Results show that the types of growing media used by the ornamental plant nurseries in the area studied, their reproducibility and properties have improved considerably in terms of agricultural results.