Hello & quest on Dutch Elm Disease natural resistance

I've been reading the posts here for a couple of weeks, and thought I'd say hello. Guy, thanks again for letting me know where you all moved to. I'm still "loris" over at GW, despite the changes there, and decrease in traffic (but didn't post often on Trees or Shrubs). Glad to see some familar names, and a chance to "meet" some new people interested in gardening. My particular interests are natives plants and habitat gardening.

I had come across something, from a source that seemed like it was reliable, that had said that in American Elms (Ulmus americana), the young trees tended to do fine, but at a certain height tended to show their susceptability to DED. I found out that I have a relatively small elm tree in my back yard (we asked the arborist from our tree service to ID all the trees and shrubs I wasn't sure about), and am wondering if we got lucky with this one or if it's too soon to tell. Unfortunately, since I tend to pay more attention to information I can use in my garden, I didn't keep track of either the details about this or where I had seen it. I'm thinking they had stated a height of 20' but I'm not sure. Does anybody know about this?

Thanks. -- Lori

We have what seem to be American Elm trees in our mixed hardwood conifer forests in northern WI., but the news is not good. The largest I've seen is about 25' w/ a dia of 5-7in. These are usually dead or dying, with bark peeling and evidence of much insect activity under bark. As I travel about I see standing old specimens w/ their beautiful trademark vase shape so I've no doubt that some trees have more resistance than others and I believe I've read of certain "named" cultivars that have some impressive years behind them. There are also crossbreds with some of the foreign elms which will give added resistance but only get you halfway to the real thing. I remember as late as 1996 walking down an old residential street in Durango, CO. (pretty isolated here from other green areas) and still experiencing the awe of the arched canopy over the street from the old trees on either parkway. Brought back childhood memories of any Chicago suburb. Bring back the elm, and then the chestnut. Ken

Hi Lori, and welcome! The GW crowd continues to grow here.

You could have your elm tested (propagated by cuttings and then innoculated in a lab) if you want spend the bucks, or else just wait and see. But unless you have some reason to think it has some resistance, rather than just blind luck or juvenility working in its favor, don't let the tree get so big that you will have problems removing it later.

Are you sure it's one of the native species (American, red, rock, winged, etc.)? If it's Asian (Siberian, lacebark, or one of the less common species) -- or a hybrid developed for disease resistance -- it will not be killed by Dutch elm disease.

There still are a few big American elms here and there (big = more than 10 feet or so in circumference), and some of them might have resistance. At least, many of us like to hope so. I know of two in my area (both more than 14 feet around) that lost all their elm neighbors but still survive unscathed, and I have heard about others elsewhere.

Big elms should be tested if they were surrounded by other elms that have died, and that's what I plan to have done with "my" two. But for any surviving elms that were isolated from other elms, it's more likely that the disease simply has not found them yet.

Guy S.

At my other place where I lived for 50 years, there were two I believe American Elms. They were there when we moved to the house, which was located at the hill side of an apple orchard. I never saw a problem with the trees other than aphid high in the trees. I finally used Cygon 2 in drilled holes around the trees to get rid of the aphids. The drip from the aphids was turning everything below black. When i sold the house 10 years ago the trees were very large. Never measured the circumference but at that time I believe the diameter was probably 30 inches for the largest one..

That was probably the most difficult thing in selling the house and moving away from all the wonderful trees. I planted just about all the trees except for the Elms. I planted 10 white Spruce (I think they were), 4 to 6 inches tall free from Arbor (what ever that Co. is that gives away trees for Arbor Day) around the edges of the yard. By the time I left half of them had grown so large that had to be removed. The other 5 are still there I noticed last time I drove by. And lots of other by now quite large trees.

DonnaS

Ken, if the trees fare in a similar way around here, sounds like I have some time. I'll have to check again, but I think this tree's trunk is less than 4" wide.

Guy, the arborist had said American elm. If you know the ID features to separate them from each other by heart, and can let me know that'd be great. Otherwise I'll try to read up (it is in a spot though that makes anything other than its trunk a bit hard to see). The tree is close enough to a pin oak that at some point I'll probably have to choose between one or the other. I think the trees we have in a park a few blocks away are American elm, so maybe it's just a matter of time as you warn.

DonnaS, I understand how you hated leaving your trees. Around here if we ever sell I'm almost sure that at an minimum people will put on an addition and kill many trees for that (one of these days I may end up losing the debate with DH and end up adding an addition myself).

Thank you all for your responses!

Lori, do not judge time alive by max dia I see in woods. I see many that die well before this. If it is an american elm what Guy says is true; It is either big with some resistance or a named cultivar from a tree with resistance, most of those would be planted in some "specimen" location not within shaking hands distance to a pin oak. I would take my chances w/ the pin oak and plant a new elm with known resistance somewhere on the property where it gets all the breaks of nature it can. Ken

Thanks Ken. Guess I was coming from this a different direction, since I'm interested in native plants, and loved the idea of helping preserve something that is having a difficult time. I have one flowering dogwood (Cornus florida) out of the 4 that were here when we moved in, and I'm always glad to see when it's still doing ok (this one's in a sunnier spot, so from what I heard has a better chance). Sounds like it's not practical to take this approach in this case of the elm. I found out I had the pin oak at the same time I learned about the American elm, and was pretty happy about that too, since this is the one and only oak I have.

BTW, I realized I really underestimated the size of the elm. I looked when I went to my yard to day, and its width is over 6" already.

Guy help me out here, isn't there some asexual cuttings of "resistant" American elms that are being marketed now with some real years behind them. Seems to me they carry a name w/ Revolutionary war background like "patriot" or "liberty"; and isn't the Morton Arboretum involved in some asexual breeding program on American Elms? I'm not sure, something in the back of my mind, probably wishful thinking, but thought you would know. Ken

American elm clones or cultivars with resistance to Dutch elm disease that are in production/distribution (or nearly so) include:

Delaware #2
Princeton
Washington
Liberty (American Liberty; less resistance than others)
Valley Forge
New Harmony
Jefferson

There are some others named, but probably are not widely available. If it is named, then it better be asexually reproduced or you're not getting the real thing. I believe all these root from cuttings.

Many/most, if not all, the Morton work is with multiple parentage hybrids of non-North American Ulmus species. Great looking trees, just not natives.

Lori, Ken is right, there are some resistant selections and hybrids. There is the Liberty series, Valley Forge, Princeton, and some others (all American elms) plus some Asian hybrids from the Morton Arb program. You need to try to determine if your tree was planted, or spontaneous. If the latter, and assuming it is American elm or another native species, it probably has little or no resistance. But if it was planted, it might be one of the resistant ones.

Even if it's a wild thing, if you value it you could have it innoculated with fungicide every 2-3 years to protect it. Your talking some money, but your pin oak also might need some treatment if it was planted in the wrong soil type (i.e. too alkaline), so you'll need to make some decisions.

Can you post a pic of them so we can see the situation, and then a bark and twig detail of the elm so we might be able to identify the species?

Guy S.

Well, the Viburnum Vallet beat me to the punch again!

Guy S.

Thank you Ken, Viburnum Valley, and Guy for the replies.

I got a hand-me-down digital camera from my BIL recently, but haven’t tried it yet. This sounds like just the push I need to give it a shot, if a picture of the bark is good enough. If my memory is right about this, the elm is tall enough that getting a picture of the twig may be an issue. Probably won’t be able to take pictures until the weekend though unless DH is willing to volunteer.

Don’t know how much this information helps, but these trees are relatively close to the fence that divides our property from our neighbors’ in back. I think they’re far enough it’ll be ok for quite a while (many of the trees in our neighborhood don’t seem to get enough breathing room). The soil usually is moist, and based on the types of plants that succeed or fail, I’m comfortable saying it’s acidic. We’ve been in the house for ages. I don’t remember when the resistant cultivars came out, but I think it’s less than 10 years. If so that would rule out its being planted for resistance.

Lori

Just so you will know their potential, this old elm still survives in the next county south from us:
http://albums.photo.epson.com/j/ViewPhoto?u=1676497&a=30963590&p=73617140

Guy S.

Guy, thanks for this link! If any of you have not done so, and I realize I'm the babe of the forum, go further in Guy"s incredible album of truely monumental trees. I've always wanted to do this, sometimes for not only the champions, but also for those outstanding in their field, if you know what I mean. Great album, and I not even done yet. Computer down in basement and wife upstairs probably saying: "Why hasn't he writen yet?" Ken

BTW, as someone asked today, you can see a side-view of this same tree on the "How Close" thread.

Guy S.

My time estimate was way off, but I finally got a chance to experiment with the digital camera. These shots may not give enough information to confirm the ID of the trees, and provide advice about which to keep, but I thought I'd try . A disclaimer first--recently both sets of neighbors behind me have added on to their houses and removed mature trees and shrubs. The clear view of my neighbor’s swing set and house if not what I would have chosen.

In this picture I'm trying to show the bark of the tree the arborist said is an American elm.

In this picture the larger tree behind the shrub is what’s being called the pin oak, and the skinny tree behind it the American elm.

In this picture the larger tree is the pin oak, and the skinny one behind it, is the elm.

Thanks. -- Lori

oh lori, these are both very nice trees, I'm sorry to have suggested a sacrifice. the "elm" definately larger that those who have died off in our woods (height and diameter). I'll step aside and let you get more professional directions from the others . Regards, ken

I wouldn't remove either of the trees you are remarking upon, based on proximity to one another. The elm is pretty close to the fence; there'll have to be an adjustment as the diameter of the elm increases, but that's pretty doable with picket fencing.

If any tree might merit removal, it would be the small tree furthest to the left and quite close to the fence in the last picture you posted. If it is a species expected to gain any type of circumference, it probably ought to go. If it is an understory type, then you might hang onto it. It's bark made me think of ash.

Thanks Ken and VV. I'll be much happier if it end ups that keeping both trees makes sense.

VV, you and the arborist agree about the skinny tree right near the fence since he identified it as a white ash. I hate seeing any of my native plants go, but at least I have other white ashes, so it won’t hurt me or the wildlife as much.

Lori

Hey Lori, I've got nothing to add but you did it!! You posted your pics and they look good! I knew you could do it...lol....

Hi Terry,

I was pleasantly surprised at how easy it was. Before I read the FAQs I thought I'd have to decide on which photo hosting site to use before I'd be able to add the pictures.

Lori

Heres my beautiful two Valley forge elms.
They are from the Botony Shop and were researched by the
National Arboretum to be disease free. I am so honoured
to have them!!!!!

They are now growing like gangbusters. In fact, I have one
that has decided to sucker and is sending up another tree.
I will shear that one off.

They will grow over 100 feet high.
sheri

Grow, baby, grow! Good for you...that's a nod to the future of a fine species.

You all will be glad to know that is a city here in Montana that is all Elm and most of them are quite old. I have assumed that due to the isolated location and dry climate in Great Falls they are thriving. I will have to take pictures of the many streets of American Elm thriving in Great Falls. The city does all of the trimming and cutting of trees but the city of 20,000+ if full of them. The main streets are draped over with the large laterals hanging over the streets. I grew up in Michigan with all the elms making my childhood fun to climb. But they are all gone now so when I got to GF I was thrilled.

Yep, saw the same thing in Durango Co in 1996. As Yogi said: Deja vu, all over again"

Deputy Dawg reminded me ken. Do you remember Tooter Turtle? I always say "Drizzle drazzle drizzle drone time for this one to come home" when I'm stuck in a difficult challenge.

Yogi Berra: circa Yankees 50's-forever. Even someone from Chi town had to love him.