2007 Glasshouse Forum How low can you go?

The 2007 meeting of the Glasshouse Forum was hosted by the National Botanic Garden of Wales.

"In the 6 years that the Great Glasshouse at the National Botanic Garden of Wales has been open to the public, minimum winter temperatures have been reduced by 4c, and yet the plants seem to be thriving. The reduction was forced originally by financial constraints, but has since been maintained because, if the plants are happy, to do otherwise seems wasteful of energy.

Other gardens are similarly reducing heating inputs. But at what point does this have to stop? Is there a real 'minimum', or are we all just doing as has always been done, without questioning received wisdom? A house with 'tropical' temperatures is being constructed at NBG Wales to grow tender plants that tie in to displays in the systematics garden, so this question has become pressing. But should we not all be examining our energy inputs, especially in the light of the Stearn report? What is the point of trying to conserve endangered plants in our glasshouses if, as a result, we contribute

to their extinction in the wild by adding unnecessarily to global warming?"