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Chinese white ash, resistant to emerald ash borer?

Posted by nick_b79 z4 MN (My Page) on
Sun, Nov 29, 09 at 14:51

Since the emerald ash borer's advance across the Midwest appears inevitable at this point, I was looking into purchasing a few Chinese white ash seedlings, Fraxinus chinensis, as replacements IF they are borer resistant. I was assuming that, since they coevolved along with the borer in Asia, they would be resistant to it. However, I haven't been able to find any actual evidence to back up my assumption and I was wondering if anyone here knew for sure? Also, is there any chance they would cross with native American ashes? Thanks!


Follow-Up Postings:

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RE: Chinese white ash, resistant to emerald ash borer?

Oh, and another question regarding hardiness. I see that Forestfarm lists them as hardy only to Z6, while Reeseville Ridge lists them as Z4 hardy.


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RE: Chinese white ash, resistant to emerald ash borer?

I don't think the problem is so much lack of resistance on the tree's part as it is a lack of natural predators to keep populations under control. They have been experimenting with predatory wasps, but I'm not sure of any have been introduced yet.


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RE: Chinese white ash, resistant to emerald ash borer?

why? why?? why??

plant an oak ... they grow faster.. EAB is not an issue.. and they live in terms of centuries ...

why risk it???

ken


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RE: Chinese white ash, resistant to emerald ash borer?

Well, we already have plenty of oaks on the farm, and the ash does serve a purpose in the ecosystem, albeit a smaller one that that of oaks. What I'm concerned about is that the native ashes will be eliminated in the same way that American chestnuts were, with no related species to fill the gap, and the forest ecosystem will change irreparably. At least a related species like the Chinese ash, or a hybrid of the two, could help to offset the death of the native species.

I'm confused by what you meant by "EAB is not an issue.. and they live in terms of centuries ... ". Could you elaborate a bit more on that? Thanks.


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RE: Chinese white ash, resistant to emerald ash borer?

  • Posted by hortster 6A, southcentral KS (My Page) on
    Sun, Nov 29, 09 at 16:16

Hey, Nick - I think Ken means that we shouldn't "knee-jerk" a solution with such a preliminary view of the problem. Preliminary meaning the first fifty years - we have a tendency to avoid seeing the HUGE process(es) that Ma Nature takes to keep the planet clean and functioning. 'Tweren't built in a day.
Who is to say that if left alone that other native species won't fill in the blanks?
hortster


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RE: Chinese white ash, resistant to emerald ash borer?

  • Posted by whaas 5a Milwaukee (My Page) on
    Sun, Nov 29, 09 at 16:47

EAB is not an issue for oaks and they "can" live for a few centuries.


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RE: Chinese white ash, resistant to emerald ash borer?

Well, there's always oak wilt...


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RE: Chinese white ash, resistant to emerald ash borer?

and sudden oak death... and bacterial leaf scorch... and gypsy moths,.... ;)


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RE: Chinese white ash, resistant to emerald ash borer?

  • Posted by bboy USDA 8 Sunset 5 WA (My Page) on
    Sun, Nov 29, 09 at 19:10

Other native elements might not interact with foreign species in same way as native. This was noticed when native songbirds were studied at arboretum here, they would flit quickly through planted specimens of related but non-native species to concentrate on foraging in native specimens in same genus.

And an introduced species would have to reproduce and naturalize extensively in order to have much impact on an ecosystem-wide basis. Another way to look at this might be "foreign invasion" or "a weed problem".


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RE: Chinese white ash, resistant to emerald ash borer?

Emerald Ash Borer is a major invasion problem in Ohio, and according to an article the university said they planted White Ash in one group and planted Ash trees from the EAB's native range in a second group in the same area. They said that the Borer insects were very attracted to the White Ash but seemed to be significantly less attracted to the Ash trees from China. They concluded that the Emerald Ash Borers did seem to attack/prefer the American trees more, but they did not know why. If the Ash from Asia had evolved some sort of defense to inhibit the Borers or what?


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RE: Chinese white ash, resistant to emerald ash borer?

Research on resistance is currently underway (see link). I've read that Manchurian ash (F. mandshurica) displays resistance to EAB, and hybrids between Manchurian and native Black ash (x 'Northern Treasure') may have a limited amount of resistance. I haven't read anything about F. chinensis being resistant, but I assume the reason is that chinensis is not as readily available to researchers as mandshurica, and hasn't been tested yet. In time, we will know more about resistance in chinensis (and other Asian species).

I believe parasitoids have already been released experimentally at a few selected locations in Michigan.

Here is a link that might be useful: Ohio State Researchers Developing Resistant Ash Hybrid


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RE: Chinese white ash, resistant to emerald ash borer?

the peeps who interpreted what i meant to say were correct ...

additionally though... of all the diversity out there.. why do you want to bang your head on the brick wall called ash ...

just before EAB came along.. in 2000 .... i invested in 6 autumn purple ash at 40$ each ... and spent ten years watching them grow wonderfully ....

i just finished removing the last of them last spring ..

nothing more disappointing than watching your investment.. and emotional attachment die to the vermin ...

and also had some other conservation dist. ash [in other words.. green and white] and they succumbed before the other ... contrary to claims that one version was bug proof ....

so i asked... why.. why.. why?????

you cant find anything other than an ash or an oak????

heck.. i would plant a maple before i would plant an ash ... and i hate maple.. lol ...

perhaps a new post on what we would recommend beyond ash.. would give you a multitude of ideas other than ash ... since you have so many oaks ....

on the other hand.. if you are talking about investing a few bucks.. and are the experimenting type.. and have no qualms about chainsawing them when the bug hits.. go for it .... which as a farm owner you probably are.. as compared to those who get all emotionally attached to the plant babes, and who have a coronary killing a bug infested tree ....... what the heck ... worse thing that happens is you find out an ash is an ash ..... and EAB is indiscriminate ....

good luck

ken

ps: as an aside.. is it possible that it could be against the law to plant ash.. since so many states are destroying them????? i know its a crime to cross state lines with cut ash.. could it be a crime to plant????


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RE: Chinese white ash, resistant to emerald ash borer?

Quick to grow, quick to die.

My favorite Ken quote.

Couldn't resist.


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RE: Chinese white ash, resistant to emerald ash borer?

I have been reading some of the literature from time to time on EAB. It's far from certain that lack of predators is the only problem with EAB. This was demostrated when our native ashes were planted in the EAB native range. These ash trees were quickly killed. Many possible reason's i.e. basically they were the most tasty around (they were the different ones) and so drew EVERY borer within miles, or stressed tress from transplant climate, pollution, any number of factors. Also there is some very very tentative evidence that some of the native predators to the native ash borer's MAY possible be adapting to attack the EAB. This is a very big IF however, and parasitism is still low but much higher than originally recorded. As for imported EAB predators, there are test releases in many areas. Good news is that they seem to survive, but it may be a while before we know how much if any true control they provide.


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RE: Chinese white ash, resistant to emerald ash borer?

Here's another link with some research info on native vs Asian ash species. It indicates that the Asian species apparently do have resistance mechanisms that our native ash are lacking. Hybrids of americana x chinensis exist and are being studied.

The link also mentions that blue ash appears to be the least preferred host of the native species.

Here is a link that might be useful: EAB host range


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RE: Chinese white ash, resistant to emerald ash borer?

"additionally though... of all the diversity out there.. why do you want to bang your head on the brick wall called ash ..."

Ken, I understand what you're saying, but understand that I am not talking about planting hundreds of Chinese ash trees on our property. We have a 25-acre piece of land, a mix of woodland and clearings, on the farm. I have been planting dozens of different species there for years, and saw that Reeseville Ridge Nursery offers 2' tall Chinese ash seedlings for $4 each. So, I thought I'd include 2-3 of them with my next order of 100+ trees this spring.


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RE: Chinese white ash, resistant to emerald ash borer?

  • Posted by lkz5ia z5 west iowa (My Page) on
    Thu, Oct 10, 13 at 21:51

I saw Oikos mention one of the Chinese Ash species in their email lately.
" Chinese Ash Fraxinus rhynchophylla

Immune to Emerald Ash Borer

This is the only ash species left at our farm after the emerald ash borer came and went. I really couldn’t understand why until I tried to prune a few branches off this species and found even with really good loppers the density and toughness of the wood is quite challenging to clip. ( A lot like pruning apricots. ) I was fortunate to get this seed many years ago from Korea where this mountainous species is found throughout China into zone 5. Ours selections are kind of slow growing compared to green ash but easy to establish in dry or poor soils low in organic matter. Late to leaf missing frosts and completely immune to the borer as far as I am aware. Some plants produce a lot of seed, others very little or none. Not really a replacement for our indigenous ash trees but worth planting just for its durability. Due to regulations governing ash, we cannot grow or sell the trees; however seeds are allowed as they contain no borers nor do borers eat them or contain borer eggs or pupae. Possibly in the future we will produce the trees again. -20 F hardiness maybe more. To sprout the seeds, plant right away in the fall and wait until next spring before the trees emerge. Our experience is that is often takes 2 years to germinate-a cold warm cold stratification period, however people who have grown the tree say plant the seeds when green or fresh and they will germinate in one year. "


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