The effects of the environment lobby on the selection and use of growing media

Horticulture has not been immune from criticism on environmental grounds, with the principal concerns of environmental lobbies about growing media being the acquisition of constituents and production of media, as well as the release of nutrients and pesticide residues into groundwater during their use. The depletion of certain types of peatland habitats, especially in countries where these are scarce, has been identified as a threat by environmental pressure groups. The same groups have argued the case for replacement of peat in growing media by more readily renewable materials or indeed by waste products. Lobbyists thus point to a dual benefit of habitat preservation and recycling of waste materials. Environmental groups opposed to the use of peat in horticulture have been especially active in the UK during the 1990s. However, peat is still the preferred medium of professional growers in many countries on grounds of reliability, uniformity and continuity of supply - notwithstanding the presence of influential environmental pressure groups. The effect of these lobbyists has been most pronounced in the amateur or hobby markets for growing media, where there is now considerable interest in the use of alternative materials. The output of waste materials in the form of leachates from intensive horticultural enterprises has contributed to the presence of nutrient ions such as nitrate and residues of pesticides in natural waters, and thus attracted adverse comment from environmental campaigners. Closed regenerative systems of growing within glasshouses and nursery stock enterprises are the subject of much current research worldwide, and moves to legally enforce closed systems are under consideration in several countries.