Fortunately, my Emperor was growing in a pot, so I moved it into the garage for a few days during the hard freeze. It didn't get as cold in NC as Midwest, but we still had a couple nights where the low got down to about 27 or so. My Emperor was just starting to leaf out, so it probably would have been damaged. Several of my dissectums that were planted in the ground (Garnet, Crimson Queen, Red Dragon and Viridis) had minor leaf burn from the freeze but nothing major. Red Dragon seens to have suffered the most burn, but that was probably due to its location more than the variety. It was in a more exposed location and the winds were very persistent during the cold snap. My A. japonicum Acontifolium was just starting to leaf out and at first appeared to have a lot of damage. The leaves all appeared to be hanging limp after the freeze. However, it has bounced back and seems to be fine now -- except that the deer keep nibbling on it for some reason. It's my only JM that the deer have ever bothered. I had about a dozen JMs in containers that I moved into the garage during the freeze, and I probably would have had a lot more damage if I hadn't done so.

The whole "atropurpureum" (not atropurpurea like I mistakenly typed) thing is an ongoing topic of discussion. Some sources list 'Atropurpureum' as a distinct cultivar; others consider it a varietal or species variation only. Right or wrong, it is a term often applied to redleaf seedlings without any other cultivar designation. And has been watered down to the point where its application towards anything other than a no-name red leafed seedling is meaningless. So I can't really answer your question very specifically :-) Yes, 'Bloodgood' is a selected variety of "atropurpureum".....you will sometimes still see it listed as Acer palmatum var. atropurpureum 'Bloodgood'. Origins of the other two are less defined -- EI is recorded as a 'chance seedling' but of what?? Typically 'Bloodgood' is considered the parent plant as this tree was on the market for a number of years as "Improved Bloodgood I" before the name was officially changed to 'Emperor I'. Exact parentage of 'Fireglow' is also somewhat murky. In the classification of J. maples, all are included in the Amoenum Atropurpureum group.

I'm not sure I understand your question. Who is the "group"? There is a great deal of research and scientific study worldwide currently being conducted on the various strains of verticillium and developing plants that have resistance, however much of the focus is with more economically significant agricultural crops. How likely this type of research will be applied to more ornamental crops is a bit of a guess, but I'd surmise there is far less financing available to fund this type of study. As to delaying the onset, much can be done by adhering to careful planting practices and scrupulous aftercare. Investigation is being conducted into various soil amendments that may contribute to neutralizing or slowing the emergence of the pathogen but nothing definitive has been concluded. Certainly developing a healthy, bioactive soil system should be helpful, as large populations of beneficial microorganisms can be a deterrent. Acknowledging the cultural requirements of the plants in question and reducing stressors that may reduce resistance and encourage the pathogen is extremely important, as stressed plants are far more likely to become infected than those in robust health. And understanding the pathogen and how it works can help as well. Once the pathogen has infected the tree, there is very little one can do to stop the progress. Generally, once the disease becomes noticeable, it is typically too late to attempt much of anything, although pruning out affected branches/tissue is reputed to help. However, since the pathogen does not always follow a predetermined course once it has invaded the vascular system, pruning may or may not be effective. Older, established trees are sometimes able to compartmentalize the disease and restrict it to a specific section of the canopy - these subjects are more likely to respond to pruning. But one of the characteristics of this disease is often a very rapid decline, after which there is little, if anything, one can do other than remove the tree. It is not curable or reversable, so even more mature trees that have successfully compartmentalized the disease remain at risk of sudden death.

Missed it by 30 minutes!! They are fantastic creatures. We have some very large ones that seem very territorial, one would hover about 18 inches from my nose staring me down! Other times if I'm sitting by the pond they have landed on my knee or hand. You can really study them then and they are so beautiful. Check out the website for the British Dragonfly Society as they have lovely pictures. Anyway BigKid, glad you rescued it!