After visit to Cornwall and seeing both the lost gardens of Heligan and the Eden Project I was convinced that there has been a golden age of Horticulture that started in the 1900s. To realize that a Head Gardener at the Heligan Estate in 1890 would be expected to know what types of manurer, through decomposition would provide sufficient heat to warm the pineapple house to bring African Pineapples to fruit. Too much nitrogen and one would have a fire, not enough and the plants would freeze. There was so much international plant material in transport when compared to what had been available in the mid 1800's. There have been problems from all of the plant material moving about unchecked... I think now with the overwhelming amount of plant material available and electricity and jet transport providing the energy to recreate environments that many of us take this for granted. It is too easy to replace a plant that has died effortlessly. I rather like the idea of Jim's "less in artificial environments" and more of zone tolerant plants in the garden. Don't get me wrong I am a plant geek I just have a hard time with plants not surviving well in the garden. for those that don't know Heligan: http://www.heligan.com/flash_intro.html