Not long after I started breeding Hulthemia roses, I observed that many cross pollinations failed to produce rose hips (hips are the fruit within which rose seeds develop). Presumably this meant that the pollen or seed parent was of lower fertility or that there was some other incompatibility. This made for a lot of work without much to show for it. Realizing that when breeding for Hulthemias, it was the blotch trait that I was trying to capture, and was really not concerned with the heritage (just as long as one of the parents exhibited the blotch), I decided to mix the pollens of the best Hulthemias with each other and use the mixed pollen for cross pollinations. This has allowed for a much better hip "take" (the hips stay on the plant to develop seeds) and a larger number of seedlings from which to select for use in further breeding. I think that this approach has allowed us to make quicker improvements in the Hulthemias by shortening the generation time.
Since each year we have been seeing progress in Hulthemia blotch development (blotch size, blotch intensity, and heat stability of the blotch), I have been using the mixed pollen of the newest (current year seedlings) that exhibit the best blotches. I especially like doing this later in the breeding season (like now), in order to take advantage of those new seedlings that are exhibiting the best blotch heat stability. Last year I posted more about how Hulthemias tend to lose their blotches in the heat in the post entitled The Hulthemia Holy Grail - Blotch Heat Stability.
Below is shown the pollen cup that I have been using to collect the pollen of the newest batch of Hulthemias that are showing the best blotches, even in our heat. I have been applying this pollen to some of the best Hulthemia seed parents, as well as to non-Hulthemia parents, including 'Darlow's Engima', 'Sunny Knock Out', 'Francis Meilland', and some of my own non-Hulthemia seedlings.
Each day fresh pollen is collected from the best new 2012 Hulthemia seedlings. The petals seen in the photos below represent 3 batches of Hulthemias that contributed their pollen for the cross pollination effort this year. These are some of the best Hulthemias that I have seen and represent improvements over prior years.