Dear All, I have grown Dahlia imperialis for some years both in very large pots and planted in the open garden here in northern Germany and they grow to exceptionlly large foliage plants. I tried to root a tip cutting in August with the idea in mind to have a small manageable plant in a pot flowering in winter but the tip cutting did not root. I grow several different clones from differend provenance but all seem to be extremely short day dependent so I never saw a flower. For the winter I dig up the roots from the garden and store the potted ones in the cellar. However I have a feeling that this year I may not be able to lift the root of a giant two stemmed specimen about 4m high in one season........ But stem cuttings root ever so easily. And I may try with a thick mulch this winter. I remember a discussion about this plant some time ago where Alberto Castillo mentioned a day length neutral form being cultivated in Argentina which flowers there in the southern hemisphere summer. I tried hard to get any further information on this special clone but no success and no further news from Alberto on this subject. A day length neutral form of this plant would be the perfect solution! Does anybody of you have come across of such a form? There are more "Tree Dahlias" than Dahlia imperialis and the earliest to flower seems to be D. campanulata but I lost this one, it simply did not sprout this spring although the pot is full of firm tubers. Others are D. excelsa which seems to be an uncertain species or perhaps a hybrid and often gets confused with D. imperialis. No flowers seen on D. excelsa either but it is much shorter and does not etiolate so much under glass as does D. imperialis. A very interesting species is the semi epiphytic "climbing" Dahlia macdougalii. It looks like an elder but flowers in winter with large bunches of small white flowers, only on VERY large specimen, though..... The last one of this group of Dahlias is D. tenuicaulis with dark red flowers but this does not seem to be in cultivation. I have brought some of them into my new empty so far unheated greenhouse hoping to see some flowers and will keep you informed in due course (hopefully!) Greetings from Germany, Uli