Dear Arpoid L; Thisd sounds like Z. aethiopica which I grew for years in Zone 5/6 where it multiplied went toseed self sowed etc. It grew without protection, but was planted near a sidewalk which probably help conserve some heat. best jim W. James W. Waddick Voice: 816 746 1949 8871 NW Brostrom Rd E-MAIL: jim-jim@swbell.net Kansas City MO 64152 Fax: 816 746 1939 Zone 5/6 - Winter low -10=B0F Summer high +100=B0F