8

Two years ago, emerald ash borer struck my region. I and several of my neighbors made the tree services rich, taking down the trees before they came down on their own and causing damages. I lost three trees total (although I gained 2.5 cords of firewood).

Of those trees, one of them was special. All of them were covered with little D-shaped holes, all of them had pieces of loose bark, and all of them had few if any leaves on their lower branches. But that one had much better bark adhesion, and many more leaves in its upper branches. Further, there are now a few saplings growing around that stump- they are full of leaves and almost 4 feet (1.3m) tall already. I've convinced myself this tree was of hardier stock than the rest, and possibly genetically pre-disposed to EAB resistance. I want to encourage that.

While I burned out the other two stumps, I've left this one, and would like to give these saplings the best chance to make it. I started this April with an Optrol (Imidacloprid) soak, and will continue each year.

What other steps should I take? Among the things I am wondering:

  • Should I pick one sapling and focus on it, pruning back the others? Would this allow that one to maximize use of available nutrients and moisture? Or would it be better to wait a few years and see which ones do best on their own? Or would it be best to let it grow as a multi-tree?
  • The stump. It is maybe just larger than one foot (0.3 - 0.4m) around and the same in height. The saplings are sprouting right at the edges of the stump. Should I cut it lower, cut it away from the edges of the saplings, leave it alone, or other?
  • This year, some blue-white shelf-shaped fungus grew on the stump. Should I do anything about that? Does this change the answer to the above?
5

In addition to the answer already given, the appearance of shelf or bracket fungus on the stump means it's dying, or doomed to die, anyway. The fungal mycelium will have invaded the heartwood of the stump, and the fruiting bodies you now see on the outside are the signal that's its well on its way to breaking down the wood of the tree. The shoots you describe as saplings, if they are coming directly off the stump, are not saplings as such, but merely new shoots, because the roots of the stump are not yet dead. If any actually have some root attached, you could try detaching it, with root, and grow on separately, that might work, but given the presence of EAB in the area, its probably best to burn out the stump and its shoots.

5

I agree with the answers from our fellow gardeners Bamboo and Stormy. Grub out the stump now and don't encourage another EAB visit to your neighbourhood. The remnants of the tree will grow until the stems become thick enough for EAB to make another visit. Searches in this forum will show a few interesting opinions along the lines of "after ten or twelve years in a neighbourhood there are no ash trees left to eat so they will all die off and you can replant". This is a very hopeful and interesting message to homeowners who like their ash trees.

A complete answer ventures into the fields of ecology and the study of invasive organisms where an all purpose answer becomes murky. Within two miles of where I live most ash trees are dead. Drive north an hour and a half and EAB has not reached there yet and they are alive. I can drive south to Maine and see ash trees in urban areas that are alive. Are they resistant or has the EAB not reached there yet?

Within the time frame that most homeowners have patience for you are better off to plant another species of tree that is native and will not provide hours of extra work or expense wondering if the Emerald Ash Borer will make a return visit. If you really want to hedge your bets plant a Gingko which is immune to many pests and now comes in most shapes and sizes you could ask for.

  • Talk about a plant that has survived EVERYTHING for 270 Million years. Oh my gosh. The gingko is actually a threatened species after all those unimaginable years!! And whoa, NOT because of anthropomorphic global warming (gag bs)!! But because everyone only plants the males. Yeah, there are male gingkos and female gingkos. The females produce this fruit that has a smell so rotten it can make one throw up. Oh us humans and our frail sensibilities can wipe out a 270 MILLION year old species just because it stinks. MONEY is killing the gingko. How sad is that! – stormy Nov 3 '16 at 3:08
  • @stormy Yes the female fruit has an unpleasant odor and that is why most plants sold are male. It is a stretch to call the gingko a threatened species. With $150 and a pickup truck I can buy one any day of the week from five or six suppliers. – kevinsky Nov 3 '16 at 10:15
  • I have always been able to find Gingko in the nurseries but I just came across an article that said Gingko was endangered. Was surprised, not convinced, but if it was endangered that smelly female would certainly help in its extermination via humans, don't you think? Grins. If it is true the Gingko is a 'threatened' species after 270 MILLION years, what does that say about us humans, sad, sad, sad!! – stormy Nov 3 '16 at 19:15
  • Gleditsia would be another Genus to recommend, Fabaceae not Rosaceae. I don't know if this is immune to EAB, but it is fine textured, easy maintenance, few diseases, insect problems and can be grown as a shade tree in lawns. Us humans and the world getting smaller is causing these catastrophes we are supposed to fix. The public needs far more information via main stream media. Ash trees should not even be available in that area...until we exterminate or at least develop plants resistant to EAB. Waste of money to replant with Ash or susceptible plants. Not to mention perpetuation of EAB. – stormy Nov 3 '16 at 19:23
  • @stormy - its endangered in the wild (gingko) I think - but commercially grown ones are freely available to buy, I planted one in the communal gardens here five years ago... – Bamboo Nov 8 '16 at 13:20
4

Here's the bad news; one NEVER plants the same genus/species in the same place where a disease or insect killed the former inhabitants. EAB

Because of the spread of EAB it is actually contraindicated and poor stewardship to plant more of their beloved foods to includes Cionanthus and Osmanthus...but there is a Chionanthus retusus that actually adapted to EAB in China. We need to starve this insect to get rid of it. EAB couldn't use Chionanthus because it produces some chemical to ward off these insects.

Bag the Ash trees...unless you want to Bonsai one for indoors?

  • I don't know how the climate of Milford OH compares to the UK, but Ash is a terrible choice of garden tree in the UK quite apart from any disease issues. They grow far too fast, are 100 feet tall and 100 feet diameter fully grown (and after say 10 years, at 30 feet tall they still look like a spindly sapling), and you get hundreds of self-seedlings every year as soon as they start setting seed. They are fine in a woodland setting, but not as a specimen tree unless you have a huge amount of space available for them. A rowan would be a much better choice for planting in a garden. – alephzero Nov 3 '16 at 1:43
  • alephzero I am confused. Are you saying that Sorbus should be planted in a garden as opposed to what? Rowan is Sorbus and totally susceptible to EAB. Tough plants except for the Emerald Ash Borer. EAB came from China where it evolved beside another tree Chionanthus retusus that produces its own 'yucky flavor' so EAB looks elsewhere. This is simply a case where EAB came across the ocean from China to find vulnerable ash trees as well as close relatives that had no immunity. entomologytoday.org/2015/07/22/… – stormy Nov 3 '16 at 3:00
  • Maybe plant a Slippery elm or Hickory instead. Pretty trees, and by now they might survive. – Wayfaring Stranger Nov 3 '16 at 13:00
  • @alephzero- Let's make sure we are not being separated by our common language. For me, the subject tree is located in the back yard which I think is what you Brits mean by garden. My garden is limited to a small patch to the side of the front walk-way where there are decorative shrubs and some perennials. Everything else in front is simply the lawn. In fact, when I think of this tree, the ideas of garden and landscaping are so far away, I initially inquired at Great Outdoors meta where this question would be on-topic. – cobaltduck Nov 3 '16 at 13:24
  • Cobaltduck, the Ash tree is a common, easily procured tree, used for street trees as well as Development type trees. Beautiful. There are lots of different Ash trees. If you have a small yard Ash is not a good choice anyhoo. Honey locust (Gleditsia triacanthos inermis moraine) is a medium sized tree that allows plenty of sun to get to the lawn. My other favorite tree for this situation is Amelanchier spps. which is native to Canada and the Pacific Northwest. It is also part of the Rosaceae family which is the same family as Ash trees so I am still looking into EAB stress on Amelancier. – stormy Nov 3 '16 at 19:49

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.