Dear All, After having written the TOW on Dahlia earlier this summer, I promised an update later in the year. I did some investigation and tried to find out more about species Dahlia. Having spoken to several people about the tree dahlias the situation becomes more confusing the more I know about it: On one hand I was told that the difference between D. imperialis and D. excelsa is that D.imperialis produces perennial woody tree-like trunks and branches several meters above soil level whereas D. excelsa produces annual tree-like shoots from the base that do not branch. In another garden I saw plants which were labelled exactly the other way round...... both plants cannot be distinguished by their foliage and it was too early to have seen flowers. However, I was told that cultivation in large pots has produced flowers as early as August in a plant that was considered D. imperialis. There is also the opinion that both D. imperialis and D. excelsa are varieties of one single species. As the plants that are cultivated in England and other northern contries are usually killed by frost before they flower being used as architectural foliage plants we will perhaps not know which ones they in fact are..... unless they flower. I saw a large bed of D. dissecta, the first flowers open and a lot of buds, light pink flowers over very finely cut leaave, quite attractive. Also D. merkii and D. sherfii, D. laciniata, D. coccinea in forms, D macdougallii, the epiphytic Dahlia which flowers in November. I is more a large climber than an epiphyte and looks like an elder..... (Sambucus) The trouble with species Dahlias is their tendency to get virus infections that kill them very quickly and the fact that they hybridize in an uncontrolled way so that the species itself is easily lost. Well... hope this was of interest for you, bye for today, Uli