As mentioned earlier, there is already some resistance present in the American elm population. Several resistant trees have been identified (showing various degrees of resistance), and there are surely more growing in the wild that have not been identified. Evolution is defined as the change over time in the genetic variation in a population. If some heritable phenotype (characteristic) becomes more or less prevalent in a population, evolution has occurred. In the case of elm trees, resistance to DED has certainly become more prevalent, since such a large percentage of susceptible trees have died. So, evolution has occurred. In this case, it does not take very long, since the genetic variation for resistance was already present in the population. Several resistant cultivars are available, and they are being planted by homeowners and parks all over the place. Pollen from these trees will surely speed up the distribution of DED resistance into the wild populations. You are correct that susceptible trees reach reproductive age before they succumb to DED. It is possible that new mutations which confer resistance will arise in that segment of the population, but there is no telling how long that will take. Such an estimate would require a lot of information that is just not available. In any case, I suspect this path wil be much slower than the one facilitated by the widespread planting of the various resistant cultivars. WRT to the DED genome project, I suspect that is more likely to lead to treatments for susceptible trees, rather than the development of DED resistant trees. An interesting quote from the link above: "itâÂÂs only a matter of time before most the elm trees are gone". I've got some news for you.....most of the elms are already gone! Alex

Last fall when I first went to the house ALL of the trees needed much care. They hadn't been pruned in decades, several were completely dead. The fruit trees were pathetic with much bark stripped off. The elms had much dead wood and needed pruning, but the leaves themselves were eaten away like little caterpillars had munched the tender parts between the veins. The only healthy, large leaves were way up on the tree, which of course I could not reach even with a tall ladder. The trees are not vase-shaped like Valley Forge elms. I would like to be proactive in spraying for whatever is eating the leaves up. I thought at first it was Japanese Beetles, but now I doubt that. It seems that Japanese Beetles have probably not even reached the Rockies yet. As soon as the trees leaf out I'll take some photos. Any idea what I should spray for and when? Thanks so much!

I have not heard that rule of thumb about 25+ year old trees. Here is a quote from an elm researcher: ============================= ""We would get numerous cuttings from people who believed they had an ancient survivor growing in their yard," says Schreiber. "But we soon discovered that most of those trees were just lucky. They had simply not been attacked by the elm bark beetle that spreads the disease." Adds Townsend, "It is not uncommon to find a single elm surviving by chance where others have died." He estimates that only 1 in 100,000 American elm trees is DED-tolerant. "Most of the thousands we tested turned out simply to have escaped exposure." ============================ I would guess that your elms have simply not been exposed. If there was really some resistance genetics there, I would expect some trees that are much larger than the one in the picture. The beetles probably have a hard time finding a few scattered middle aged elms in a mixed species forest. Also, since the beetles don't feed on elms until they are several years old, it may be that, when all the big elms in the area got wiped out, the beetles moved on, leaving a few young trees that grew into the specimens you see now. Alex Here is a link that might be useful: source for quote

I have several wild American Elm growing on my property near Waco, Tx. I still have at least one of these potted (about 2' tall). IF someone wants it, I will send it to you bare-rooted free of charge up until end of April, except you must agree to post here annually its growth results and agree to at least weekly watering if no rainfall during spring -fall for first year. Our American Elm here appear to be DED- free, but the trees are much shorter than described back east. Our native Cedar Elm appear to be the better choice for here, but the few large American Elm growing only along river and creek beds do look nice. I am not an expert on American Elm, only an interested observer on the western fringes of their territory.