We are asked frequently about the Craig pelargoniums, and what we are doing with them. This is quite a long story, and is likely to cover multiple blog posts.
G2 is preserving the Craig pel collection by converting as many of the vegetatively-propagated varieties as we can into seed. To do this, we are self-pollinating each variety until we collect at least 100 seeds.
When an individual plant is not pollen-fertile, we pollinate it with a sib, if one is available and if the sib is pollen-fertile. In this way, we preserve most of the unique genetics contained in the individual variety.
When a particular variety is not pollen-fertile, and there is no sib available, we cross the variety to two unrelated commercials, of different colors, and different habits. In this way, we preserve the unique genetics of each of the Craig varieties in two distinctly different genetic backgrounds. 
This is obviously a lot of work. We've already been working on this for two years. It appears that there is at least another year of preservation work to do before we are confident that we have done as much as can be done.
Dr. Craig maintained active breeding programs in multiple Pelargonium species. He bred zonal geraniums, tetraploid P. xhortorum. Some of his most successful zonals included 'Misty', a truly uniquely-colored pink (PP7350), 'Jubilee', one of the best outdoor-performing zonal ever released (PP8089); and the top-selling Craig variety for many years, 'Juliet' (aka 'Risque') (PP6654). All of these were released through the Oglevee organization.
In order to protect his zonal inventions, Dr. Craig and Penn State obtained Plant Patents on them. As part of the plant patent applications, Dr. Craig frequently provided detailed chromatograms of their unique pigment profiles. I had the privilege of working with Dr. Masood Arjmand and Kevin Lloyd at Centre Analytical Laboratories during my Ph.D. days as they were developing these "pigment fingerprinting" analytical methods, and then applying them to the Craig pelargoniums. At that time, these "pigment fingerprinting" projects were funded in part by the Ben Franklin program, an economic development organization funded by the state of Pennsylvania.
This is probably a good point to tell you about what was probably the most significant variegated Pelargonium in the U.S. for many years:'Ben Franklin'. 'Ben Franklin' is a diploid xhortorum, just like most of the common seed-propagated geraniums. It resulted from a cross between the European variegated cultivar 'Wilhelm Langeth' and 'Snowmass, a cross which was made in Dr. Craig's greenhouses in 1978. 'Ben Franklin' (PP6218) was released in 1988.
Here is a picture of Ben Franklin.
Dr. Craig's academic research with xhortorum included a significant amount of work with pathogen- and pest-resistance. One of the more unique crosses which were performed in these projects were crosses between tetraploid P. xhortorum and tetraploid P. peltatum. Linda Laughner (PSU MS 1985, now a breeder with Ball Horticultural, Santa Paula, CA) crossed 'Veronica (PP5054)', a brilliant violet-flowered zonal by the dark-red-flowered ivy geranium 'Yale'. 'Veronica', like almost all xhortorums, is mite-resistant but rust-susceptible. 'Yale', as with almost all ivies, is mite-susceptible but rust-resistant. From the few seeds which Linda successfully produced from this interspecific hybridization came a plant which was both rust-resistant and mite-resistant. Furthermore, this seedling and some of its subsequent progeny (we maintain two, 85-8-1 and 85-9-2 in the G2 greenhouses) also displayed that deep unique dark 'Yale' red color from the peltatum side of the cross. This color which was not seen again in zonal Pelargoniums until the wildly successful 2008 release of 'Caliente Fire09' by Syngenta/Goldfisch. We've got both 85-8-1 and 85-9-2 in the greenhouse making seed. When we can spare an inflorescence, I'll take and post a good picture so you can see how rich this color is in the interspecific progeny. 
