A project called 'biodegradable containers, naturally good' was commissioned by the Product Board for Horticulture, the VBN, VBA Auction and certain provinces and effected by DLV Consultancy and Applied Plant Research Institute at Boskoop. Various types of biodegradable pots that use paper and/or peat, coconut fibre, pressed organic material and biodegradable plastics were tested with a wide range of plants: Primula, Viola, Poinsettia, Tibouchina, Lantana, Andomeda, Chamaecyparis and Pieris. The general conclusions were that biodegradable pots are not yet optimally suited to mechanical handling but their strength and light weight are acceptable. In most cases vegetative growth and root growth were inferior to that of the control plants growing in common plastic pots. This might be due to light trasmission, noxious substances being released during the decomposition of the pots or inadequate drainage. The surface of some of the pots was not smooth enough; it proved difficult to loosten plants from the ports when trasplanting. A finer pressing/moulding of the pots together with ridging could overcome this problem. The soiling of the pots by algae and fungi became very apparent on some of the pots while others remained almost completely free during the experiment. Those using paper/peat as raw material need to remain relatively dry. The manufacturers need to examine the characteristics required of biodegradable pots by professional growers ad landscapers in contrast to the distribution chain and consumer. In the latter case, aspects such as firmness, damage proof, attractive and cleanliness are important. The study concluded that it should be possible to adjust production systems to suit the use of biodegradable containers. A report is available from: DLV Consultancy Group. Contact Ms. C. van Raak Tel 0031 411 652525 Pieter van Dalfsen "FlowerTech" www.HortiWorld.nl E-mail: P.van.Dalfsen@PPO.DLO.nl