On 5 Jun 2014, at 22:11, J. Agoston wrote: > With F. imperialis i had no luck keeping them longer than 1-2 years... A professional horticulturist once told me that F. imperialis needs extra potassium. But before doing that, I would find climatic records for your location and for a location where F. i. is known to thrive - probably in Iran - and compare the two. It may be that the pattern of weather with you differs too much from that in F.i.'s native haunts. I have a problem that is analogous: Japanese plants fail in my garden because (I believe) the annual pattern of rainfall is exactly opposite from that in Japan. We have dry summers and wet winters, the winter wet aggravated by poor subsurface drainage in my garden. Japan has wet summers and dry winters. If a Japanese native doesn't desiccate to nothingness in summer, it rots away during the winter. Such plants can be grown in pots if you remember to store them under cover during the winter. -- Rodger Whitlock Victoria, British Columbia, Canada Z. 7-8, cool Mediterranean climate