Hello Elena,
thanks for your reply. I had the same experience here - some of the cultivars registered as late or very late did never flower late for me, but many of them just needed 2 or 3 years to adapt to our climate and then startet to perform as expected.
Coral Majority e.g. now flowers here from Mid July till Mid August (which is late in my region) - the first years it startet in late June (just before peak bloom).
At the moment my own plants are tested in different European climate zones (in northern Germany where it is cool in summer but not so cold in winter and in our alpine region with colder winters and summers as we have) - up to now all of them start to flower a little bit later than in my own garden.
Maybe you want to take a look at my registrations and give me a feedback - up to now the latest ones are diploids which flower within the first days of October here. But I'm planning on converting the best mother plants to get cold hardy tetraploid ones too that open good after cool nights (around 45-50°F) . You can find them here:
https://garden.org/plants/sear...
The last two years I used frozen pollen from earlier flowering cultivars to get bright and saturated colors, eyes, edges, stripes and other fancy stuff in late seedlings - I hope to see the first results this year. But you have to keep in mind, that the plants shall fit in autumnal bed situations - they may sometimes need other colors or effects than beds in early summer. So how will your ideal Hem for August or September look like?
Could this seedling be a candidate?
Started on Aug 2nd and finished about 4 weeks later - Techny Peach Lace x Late Starter:
