I would grow it in the greenhouse. My plants usually flower in Aug-September in comparison to henryi which usually flowers in June. I have summer heat in the 90's (F) with moderately cool nights (down to 55F in a pleasant summer). Rosthornii sets seed and I usually have bulbs for sale, but no one buys them so I now just let the seed fall and germinate..... Germination is immediate and plants mature quickly. Aaron --- On Thu, 4/4/13, Gene Mirro <mirrog@yahoo.com> wrote: From: Gene Mirro <mirrog@yahoo.com> Subject: [pbs] Growing Lilium rosthornii for seed To: pbs@lists.ibiblio.org Date: Thursday, April 4, 2013, 11:20 PM I read that L. rosthornii blooms after L. henryi, which is already quite late. I would like to collect seed of rosthornii. Summers here are cool and short. Should I grow this species in the greenhouse?