Apologies on the tardiness of my reply.
Apparently some hart seeds stowed aways in some Utrics I got from Jim 2 springs ago. Not sure how long after I had received the utrics when I spotted some sort of unidentified Drosera sprouting. These turned out to be hartmeyerorum. The plants summered outside on my balcony -- unobstructed SE exposure. They received full sun from 8am to around 12/1 pm after which they were somewhat shaded overhead by other plants though I imagine still received a great deal of reflected light off the glass doors of my door wall. Once temps entered the 40's they were brought indoors where they wintered on a lighted plantstand. Winter temps ranged from the upper 50sF by night and mid 70sF by day. RH was 30 or less which did not seem to bother them one whit. Once temps warmed up in the late spring, they went outside once more. Plants continued to grow and began blooming. Blooming continued through the summer. My last plant from that initial group died just a couple of weeks ago.
Seed production is prodigious but germination, for me at any rate, has been rather erratic. I have had seedlings appear in pots where I never sowed them. Whether these were other stowaway seeds or simply ones that had somehow gotten carried by an errant breeze to a pot 5ft away with an obstacle course of various plants in between, I have no idea. From the same sowing, I currently have some plants that are 2-3 inches tall to others that are only about 1cm -- all in the same pot.
The media the utrics came in was, I believe, peat and coarse silica sand. I currently have plants in pure sphag as that is what I had on hand. Further investigation utilizing different media is warranted.
As annuals, there should be no dormancy.
