How Emerald Ash Borer is Making its Way Out West

Scott Gardner, district manager at Davey's Vancouver, British Columbia, office joins Talking Trees to discuss the recent emerald ash borer (EAB) sightings that have plagued multiple Canadian municipalities and parts of the United States. 

In this episode we cover:  

• Vancouver's climate (:48)
• Has emerald ash borer (EAB) reached Vancouver? (1:38)
• Scott's first experience with EAB (3:01)
• EAB prevention measures (4:15)
• Scott's EAB treatment recommendations (5:44)
• How are Candian municipalities using ash trees? (6:53)
• Scott's initial reaction to hearing about EAB in Vancouver (8:52)
• Have affected areas been able to remove trees infected by EAB? (11:30)
• Which trees can replace those that were infected by EAB? (12:28)
• Which trees would Scott like to plant in Vancouver? (13:57)
• When do you remove a tree infected by EAB? (15:33)
• Can EAB be slowed down? (17:09)

To find your local Davey office, check out our find a local office page to search by zip code.

To learn more about emerald ash borer, read our blogs, Protect Your Ash Trees: Spot the Early Signs of EAB and The 101 on Emerald Ash Borer.

Connect with Davey Tree on social media:
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Facebook: @DaveyTree
Instagram: @daveytree
YouTube: The Davey Tree Expert Company
LinkedIn: The Davey Tree Expert Company 

Connect with Doug Oster at www.dougoster.com. 

Have topics you'd like us to cover on the podcast? Email us at podcasts@davey.com. We want to hear from you!

Transcript

Doug Oster: Welcome to the Davey Tree Expert Company's podcast, Talking Trees. I'm your host, Doug Oster. Each week, our expert arborists share advice on seasonal tree care, how to make your trees thrive, arborists' favorite trees, and much, much more. Tune in every Thursday to learn more because here at the Talking Trees podcast, we know trees are the answer. I'm joined again this week by Scott Gardner. He's a district manager at the Vancouver, Canada, Davey Tree office. We're going to talk all about emerald ash borer, Scott. Before we do, I want to say that I got to visit Vancouver a few years ago, and I've never seen hydrangeas bloom like that.

Scott Gardner: Honestly, they just go crazy. It's like a wall of flowers. It's fantastic.

Doug: Before we get into emerald ash borer, talk a little bit about your climate. Is it some amazing place to grow things? Because as I said, when I was just walking through a public park, there were hydrangeas that were the size of 10 by 10, maybe even bigger.

Scott: With it, it's hard to kill things out here. The trees, we have had a lot of drought lately. Outside of the drought, we have a lot of rain and mild temperatures. We don't have really cold winters. We've seen years where sometimes trees will bloom twice in a year, where they normally would only go once. Things thrive in this environment, for sure.

Doug: Yes, it looked great when I was there. Let's get into emerald ash borer. My understanding is you have not seen it yet, but it is very close.

Scott: With it, we have positive exposure to it. We've identified four trees that have been completely killed from it. You can see the tracking, everything else. In looking at some juvenile trees, we've actually identified adults emerging. I collected a few of those maybe three weeks ago.

The Canadian Food Administration is doing an investigation where they're setting out some traps and trying to see how far it's spread. They've identified, I think, 20 different trees that have tested positive. It is here. It is expanding. The population of the trees in Vancouver's proper, where it was discovered, is only 7,000 throughout the entire city. It's a smaller population, but I don't think that that'll affect the expansion given the fact that they grow so exponentially.

Doug: What was your first experience with emerald ash borer?

Scott: When I started in the industry 10 years ago, we were right in the heart of EAB in Ontario. With that, we were taking down 5,000 trees a year. We had 10-plus crews just in the office that I was working at that were dedicated to just removing the trees, limbing them up, bringing the [unintelligible 00:03:30] and just [unintelligible 00:03:31] out the trees. I think we had three or four trucks that were just doing stump grinding on them.

I think there was 500,000 trees in the city that had to be removed from this. It's just a wave of destruction. The worst part about EAB is you can't use cultural practices to really help your trees. There are some injections that can be done, but the watering, fertilizing, doing all the best, thinning, deadwooding, all of those things don't do anything to the effects of the borer. It's very bad for the trees when it comes through.

Doug: It sounded like it was devastating in Ontario. It was devastating over here in Pittsburgh. What is your thinking as it is just arriving now? What do you think is going to happen? What can you do? If you've got a big ash tree, you better treat it, right?

Scott: If you have a big ash tree and you want to keep it, yes, you have to treat it. The other thing that you can do is start looking at replacing it, planting a secondary tree to take over the space, treat it to try to keep it. Even with the treatments, like you have to do the injections every year, every two years. As soon as you stop, it will die so long as the bug is prevalent in the landscape. To eradicate a pest is near impossible. So long as there are ash trees, it will be lingering.

I think when we were doing a workshop on this the other day, they were saying one adult can lay 80 larvae. 1 to 80, do that over three generations, you have millions of emerald ash borer. With that, it only takes one to really create a massive expansion, especially with the populations of the trees being what they are.

Doug: When you are talking to a client, what are you telling them? Are you telling them, if you want to treat it, it's going to be every year, and are you recommending treatment, or does it depend on the situation? Are you recommending like, "Hey, it's eventually going to die anyway, get rid of it"?

Scott: The ironic scenario in BC is the majority of ash trees are owned by municipalities. Private owners don't plant many ash trees. There might be one or two. I think we have a few of the larger complexes that might have some, but the largest stakeholder in this is the municipalities, and they have thousands of them. The idea of treating them is not a small cost or a small price tag. With it, at this point, the biggest thing that we're telling them is to start setting out a plan because it's a massive amount of plants that need to be addressed, and it's inevitable at this point.

Doug: For municipalities, how are they using the ash trees? Is it like a street tree, shade tree type thing?

Scott: Yes, street trees and shade trees. They're not as prevalent. I think Alberta, there isn't any emerald ash borer in Alberta, but they were saying that they had planted over a million ash trees as part of a shelter belt program. Then, I think the city of Edmonton has 80,000 just in the city. With it, the impact in the prairies is going to be a lot larger, similar to Pittsburgh, or what we've seen in Ontario.

In BC, I think they're probably just going to replace the trees and maybe do some treatment to expand the program, depending on how they want to do it. It's a case-by-case scenario where hopefully we try to contain it and minimize or slow the spread, but really the spread, I don't think that it's going to be possible to contain it. I know with Asian long-horned beetle, they've been trying to contain that.

They've had a variety of success with it, depending on how aggressively they treat it. If we are able to contain it here, I would be absolutely surprised and impressed. It's just going to have to be diligent in disposing of the debris properly and not taking firewood up the coast and expanding things. Because that's the problem, right? You cut down all these trees, nice wood, and everybody wants to take it all over the place, but there's larvae in there. It's only a matter of time before it pops out. All it takes is one piece of wood to get that one adult into the wrong place, and we're back at square one.

Doug: As emerald ash borer was approaching your area, what were your thoughts as a tree lover and someone who works with trees every day?

Scott: I've been in the Lower Mainland for the last, let's say, six years, and there has not been a peep about it the whole time. I know a year ago, it was identified in Portland. That was the last time I'd heard about it. It hasn't been something that has-- Nobody's really been planning or doing anything for it up here. It's just a, oh, there's no way it's ever going to make it here. It was only by luck that they found it. There was a junior entomologist that happened to be in the park and one of the beetles landed on their laptop. They cupped it up, sent it to a friend, and the guy's like, this is emerald ash borer.

He happened to know the main guy with the Canadian Food Administration, sent it to him. They identified the location, they surveyed it, and that's how they discovered it. The fact that we know about it this soon is tremendously beneficial so that we have a chance of trying to contain it before it gets to the point that just all of the trees are just dead.

Doug: What do you think is going to happen?

Scott: I think they're all gone. The skeptic in me is, I think that there's a chance that we're going to do a heavy quarantine, remove all the trees in the area, treat the ones around it to try to contain it so that they don't have the ability to spread. I think that that may last. The amount of expansion within the city based on the maps that I've seen make it seem like it's growing fairly rapidly. If we find that it has jumped to another municipality, so the Lower Mainland is filled with maybe 20 different municipalities, if it got to any of the other municipalities and is in multiple pockets, I would say it's too late, they're all gone. Wishful thinking, I would say, hopefully we can remove the affected trees, treat the ones around it, and try to contain it. I'm very skeptical.

Doug: Yes, I know. Have we heard of any municipality, any area where they've been able to do that? Everybody wants to do that when they hear EAB is on the way, but that emerald ash borer seems to be able to keep moving.

Scott: The fact that it's even here is just a testament to how pervasive it can be. Because, yes, it's been down in Portland, but how did it jump from there to here? Why is it so prevalent here now? That's the thing. There is no real reason why. The theory has been that it came in the ports, it came in packaging, or something of that sort. It would be great to know how it spreads, but there isn't really much evidence to where it actually came from. We only know where it ended up.

Doug: Assuming that certainly many of these trees are going to die, and we know it has to be right tree, right place, but what are you thinking about the replacements?

Scott: Since we've been looking at the different populations of ash trees in different cities, you see different diversity of tree species in those different areas. If you look at Edmonton, I think they have between 20% and 30% of their population of trees as ash trees. The biggest thing is going to be having diversity so that when a pest comes through, rather than having 30% to 40% of your canopy being destroyed from one pest, have it that you have 20, 30, 40 different species divided and have it that you don't have more than 10%, 20%, 30% of your population as one tree.

I know it's tempting to have a beautiful boulevard with the same trees the whole way down, arching the whole thing. You've seen it in the movies, you love it, but the problem is it makes it a lot more susceptible that you're going to lose that entire row. If you did want to have single rows of streets that were the same species, at least have it that you're only losing one street worth of trees, not half the city.

Doug: How about some species that you would love to grow in Vancouver that maybe isn't getting planted as much, and we can have a nice diverse street tree, shade tree area?

Scott: I want to say locust. The other problem with the Lower Mainland here is there's a very high population of prunus, so the cherry trees. If there's something that hits the cherry trees, that's another 20%, 30% of the population that's going to be dropping. I think definitely staying away from that. I would say locust trees is one. The temperature here--

Doug: They're Indestructible, right? Indestructible locust trees.

Scott: Yes, I want indestructible trees. That's what I would be recommending. The other thing is we commented earlier on about this being a great place that anything can live. Now, we've been going on five years of two to three months of drought. With it, we're seeing maples and cypress and cedars, mature trees, just dying. No sign of anything else, just straight from the water and the heat stress. I would say if we're going to be planting trees, I would be looking for varieties that are very heat-tolerant, or not susceptible to heat damage, and not wanting as much water. Because those ones, they're the ones that are going to be on the chopping block next.

Doug: All right. I'm going to propose a scenario here. Let's say that you are contacted by a municipality. They have ash trees going all down the street. They've seen the EAB there. Do you wait until, and they say, "We can't treat. There's not enough money to treat all these trees"? Do you wait until the beetle starts to do its thing before you remove the tree, or do you remove the tree before the beetle gets to it?

Scott: If they're not planning on treating, I would remove right away. The thing with it is, you're going to have to remove it anyways. The biggest thing is to spread that cost over a longer time horizon. Once the trees are being removed after five years, then they start to crumble, fall apart. They become unsafe to deal with. They become unsafe for the public. If they've decided that they're not going to be treating, I would say, and you know that EAB is in the environment, I would say start removing right away. If, say, you have three to five years of removing as you're leading up to a full infestation and spread, remove those, you have five years before, five years after it. Now you have a 10-year timeframe, as opposed to waiting for them to be completely dead in five years. Then having it that they're falling apart, be in a rush, have to put up your budget, have to spend more on it. That would be my advice to municipalities.

Doug: We're both skeptical on whether that pest can be slowed down. If anybody can do it, you guys are on the very beginning of seeing it. I hope that you can at least slow it down because it is such a devastating thing to lose, in our case here, all the ash trees.

Scott: Yes, honestly, I would love if we were able to identify it and actually contain it here. It would be fantastic if it does become possible. Like you said, we're both skeptical to that. We're human, right? All it takes is one person breaking the policies, moving a piece of logwood for it to all go out the window. My skeptical side will say that's probably not going to happen. If we are able to accomplish it, as-- because there are so many stakeholders, there's the municipalities, there's multiple companies, there's just the general public. If, as a group, we can all come together and tackle this, and actually eradicate it, that would be fantastic.

Doug: Scott, I hope that that works. I hope the next time that we talk, we'll talk about something more positive, okay?

Scott: Sounds good, Doug. It's always a pleasure talking.

Doug: Thanks again. We'll check in again with Scott for an update on how things are progressing there in Vancouver in an upcoming episode. Now tune in every Thursday to the Talking Trees podcast from the Davey Tree Expert Company. I'm your host, Doug Oster, and do me a big favor. Subscribe to the podcast so you'll never miss a show. If you've got an idea for an episode, maybe a comment, send us an email at podcasts@davey.com. That's P-O-D-C-A-S-T-S@D-A-V-E-Y.com. As always, we'd like to remind you on the Talking Trees podcast, trees are the answer.

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