mdo, I can shed a little light on this: With the Emamectin Benzoate-style treatments available now, tradenamed Tree-age (The 'a' has the two little umlauts or whatever they're called above it, and the word is pronounced like the word triage), it is reasonable to expect two solid years of control from a single treatment, and quite possibly three years. For high-value trees like yours, this seems like a reasonable thing to do. Alternatively, the Imidacloprid insecticides will give a single year's control but are easier to apply. So even that's not a crazy thing to do. Environmentally speaking, either one of these methods is fairly low risk to surrounding organisms, being either injected straight into the trunk, or spread on the ground and soaked in via watering or rainfall, depending on which chemistry you reach for. The other half of your question I can answer too: What seems to happen with EAB is similar to other exotic insect invasions-there is a ramping up period, a period of overwhelming infestation, and then, just as you'd probably expect,a leveling off period after the insects have killed most of their hosts. So if you do happen to save yours during the hot time, you would still need to treat to have the surety of protecting the trees, but overall pressure would level off a great deal. These two lines of thought are straight out of very recent arborist's convention/seminars, so they are up to date. The relevance of this winter's cold temps was also a hot topic (Buh dum bum), but in reality, most thought is that while some of the less-deeply positioned larvae may indeed be killed, EAB has two larval forms and one of them is positioned deeper into the trunk, likely meaning the weather will have fairly little impact one way or the other. We can always hope though! +oM

Scot, good point. David, thanks. Sounds good. I was planning to get a Lacey oak which is native to my area and said to be oak wilt resistant, but I was told by two nurseries that none are available from their wholesalers this year. Also just read on line that it had been shown to be susceptible to oak wilt, so guess that variety is out. First I was considering a very different tree just because I liked it's looks and don't need a dense shade tree, Palo Verde 'Desert Museum'. It was widely available last year, but now same thing -- none of the wholesalers are carrying it. Anybody know why? I'm almost tempted to wait for it IF I thought I could get it later. Any ideas? Here is a link that might be useful: FYI Scroll down to The Bad News ...

OK Mike, though Ash trees of your size are literally dirt cheap to self protect each April from EAB. $20 worth of generic drench for 20-25 year old tree like yours. Even if removal and replacement costs over $600 per tree, unfortunately structurally wise your untrained trees will require a lot of corrective pruning. By removing poorly attached limbs, and removing or slowing down any competing leaders. With the observation of adventitious trunk sprouts and prolific flower production, those cruddy round balls that stay on tree even in winter, because of an iconic aphid problem. Either local EAB have already begun damaging your trees, or they are already in poor health. Similar to declining trees mass production of seeds every year, signs that a tree is suffering traumatic event. And prolifically seeds in order to produce offspring to keep its family line going. By observing how each tree looses its leaves in fall, or if individual limbs loose leaves as early as August. One can get an idea of how much damage EAB caused that year, and what limbs might not come back next year. You may even end up with one individual tree dying off before the rest, as arriving EAB attacks weakest ones first. And after most Green Ash killed off locally, borers will primarily begin attacking single leaf Ash, Black Ash, UK Excelsior, then White Ash in earnest. Last to go is Blue Ash, which is North America's oldest ancient progenitor Ash species. Rather than just let all your Ashes be killed off by EAB, then remove. (Not that anyone will even notice trees declining, only after they are removed) I suggest temporarily protecting best one or two, while replacing the rest. Unless you can get discount for group tree removal. This will spread replacement cost out over few years. Or if selling property anyways soon, treat trees and let next owner deal with it. But if trees are dead when selling property, inspectors will notice and compel you to either remove at your cost, or minus worth from final price of property sale. If not planning on replacing anyways, then treatment might be best option. Just think of treatment, like applying beneficial fertilizer each spring. Ironically someone living in city or along major road would have better success planting Ash, than Maple or Linden. Since before arrival of EAB, Ash had proven to be one of most superior urban species. Best extended flood and drought tolerant, survival of road salt, along with super compacted soil and planting too deep. At worst developing into super slow growing dwarf tree, where other species would die. And along with superior surviving Honey locust and Sycamore, young Ash can produce good structure without required formative pruning. Heck, before todays cultivars, 60 years ago Ash was even more iconic than sycamore for producing strong apical dominance. At least all these quality traits hold true for wild and planted ash here throughout the Midwest. And not true for states like California or Hawaii who primarily planted Raywood Ash, a crappy cultivar that structurally puts callery pears to shame. If Nursery or contractor sold you these Ash after 2002, by time EAB officially identified. I would not purchase new trees from anyone who failed to warn you its species faced future problems and had limited lifespan. (But your 20+ old trees look like planted in 1990's when already 6-7 years old) I also suggest self educating yourself on topic of good condition tree selection at Nursery, and correct installation method of B&B trees. One would think that's what experts that grow and plant trees are for. After all, its their career. But while they do know how to do things the right or wrong way, its up to customer to actually request that things be done correctly. Which they will have no problem doing, as long as one just asks. Otherwise contractors save time by installing trees the outdated way, thus shortening its potential lifespan in the end. But today customers may not even notice if tree planted upside down. Since even upside down trees can last some five years, just like incorrectly planted ones do. Here is link to this old house video explaining what a primary root flare is and looks like. https://www.youtube.com/watch?v=fI12XNNqldA And actually one of most beneficial things one can do for new tree, is sweep its root flare clear of any accumulating soil or mulch each April. Because an expanding root flare is a trees evolved tool, preventively severing any circling roots that may strangle tree, by using buttress root pressure. Trees lacking any visible flare above ground, especially trees with trunks that resemble poles entering ground. Are programed for obsolescence within one decade. Worst of examples, are any trees that have landscape walls built and filled with dirt around their now buried bases. Making this fad, literally number one way to kill a tree. Along with Mulch/soil mounding fad which is now expected to claim more trees lives...than EAB and Dutch Elm disease combined! OK Mike, hope I helped you become a smart Ash, ha.

>It started with developing a collaborative relationship with the city's forester and working towards a common goal of re-foresting a park that has a no-dig archaeological restriction. I supplied the new trees< Two key points being the city having a forester in the first place and you paying part of the cost of the project yourself. Here the municipal economic development committee gets about 10 times the participation and support as the tree board, with the City even undercutting the tree board on one occasion during the time that I was involved. During the latter part of my participation the parks department was starting to move in the direction of having some version of a municipal arborist. By adding this responsibility to those of an existing employee, rather than fully funding and recruiting for a dedicated position. Since then a particular type of redevelopment has became prevalent in the area, wherein everything existing is removed and replaced by several story rectangles that fill nearly the entire, sometimes block long space. Once this is continued long enough it's going to start looking like San Francisco in the vicinity of Golden Gate Park around here, that is a bunch of generally homogenous architecture with little more than street planting pockets - if even that much space - left for trees.