How Trees React to Shifts in Weather Patterns

James Steffel, plant health care coordinator for Davey's North Minneapolis office, discusses how rapidly changing temperature and precipitation patterns can impact your trees.

In this episode we cover:  

• Shifts in the weather in Minneapolis (:38)
• How long has Minneapolis been in a drought? (2:03)
• Heavy rainfall periods in Minneapolis (2:52)
• Minneapolis temperature patterns (4:13)
• How are trees reacting to these weather pattern changes? (5:10)
• Wood-boring insects and weather pattern changes (6:45)
• What can we do to prevent weather pattern changes from impacting our trees? (8:16)
• Emerald ash borer in Minneapolis (10:02)
• The importance of a diverse tree canopy (11:18)
• What James does in his role (12:39)
• What are humates? (15:14)
• Why is this job right for James? (16:57)

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

To learn more about swings in weather patterns, visit our Climate Change page, and read our blog, Climate Facing Trees For U.S. Metropolitan Areas.

Connect with Davey Tree on social media:
Twitter: @DaveyTree
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

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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.

This week, I'm joined by James Steffel. He's a plant Health Care Coordinator for the North Minneapolis office, the Davey Tree Expert Company. James, how are you doing today?

James Steffel: I'm doing pretty good. Glad to be on. Thanks for having me.

Doug: You came up with this idea in talking a little bit about this wide swing in weather patterns that you've seen in your area. Talk a little bit about that, and what made you want to talk about that?

James: Well, basically, over the past decade, we've been just seeing these wide weather swings of historic droughts, to back in 2016, we had the wettest rainfall on record, and it's just been fluctuating back and forth more and more, it seems like, and the trees are responding to that. They're abnormally stressed compared to, if you have a super, super wet year, you're going to have a bunch more funguses, and a bunch of like armillaria, phytophthora, blights, and different things happening, and then it just flips on its head, and then all of a sudden, it gets really, really warm.

We've been just seeing a lot of two-lined chestnut borer, emerald ash borer, and other flatheaded borer issues. These trees are just getting hit from both sides. It's not like it's a gradual change, it's been just exponential growth and heat, and different areas where these trees are just-- They're just responding differently to these different, abnormally adverse weather patterns we've been seeing.

Doug: Let's first talk about that drought period. How long did you have a drought?

James: We've been in about a three-year drought. We've broken it this year, and we're switching to more rain. Last summer, it stopped raining, basically, sometime in May and April, it was raining, and then it just stopped, and it just didn't rain all year. We had somewhere between 18 and 90, 90-degree days, and it was just extremely dry, and everything was just-- It was just really bad.

Lawns were fried up everywhere, trees were getting drought stress response, crab apples, we were getting called out for what people thought was apple scab, and it was just drought stress, and the trees were just shriveling up, and it was pretty bad.

Doug: Then, what about the periods of lots of rain?

James: Well, 2016, 2017. 2016 was, like I mentioned earlier, one of the wettest years, was the wettest year on record with over 42 inches of rainfall. We're averaging like a 28-30 inch, so pretty extreme. It's shifted too. We had super, super wet year with rain that year. Then, the same thing was snowfall packed, like last season, we had one of the lowest snowfall counts ever.

Then, the year prior to that, we had one of highest snowfall counts ever. It's just-- It's fluctuating, where we're either getting dumped on with extreme amount of precipitation, or we're getting virtually none. Where this season, it seems to be, we're getting a lot more than normal, but it just hasn't been like that regular rainfall amount. I now understand that things shift between a super wet year, and a super dry year.

That's natural with weather patterns, but it just seems to be trending to more, more, or less, less. It's not averaging out from what I've seen, at least, in the last 10 years.

Doug: Then, how about temperatures?

James: Temperatures, like I said, this past season, it's been a little cooler. Last three years, it's been really hot. A lot of really 90-degree days, really humid. It's been, especially, in the Twin Cities area, we get that urban heat island effect. I know a lot of cities get that around, where it just gets another 5 to 10 degrees hotter. It's been really hot.

Last winter, actually, was one of the warmest winters on a record. I mean, the ground didn't freeze hardly at all. We had one cold week where it was in the 0s and 10s and teens. The rest of the winter, it felt like I was in Ohio. It felt like I was in a different state in the winter time, because it just wasn't cold.

Doug: Let's talk a little bit about the trees. How have they responded?

James: Basically, with the super, super dry conditions we've seen over the past three years with no rain, I've seen maples that just don't leaf out. They just put on a really big seed year, put as many seeds as they could, and then they just didn't leaf out the next year. We're also-- I've seen the same thing with lilacs. Some of them just, you can see the drought stress where the whole, the outer part of the canopies is just like dead twigs, and the inner parts got some growth left on it.

It's just a drought stress response, because they just weren't getting enough water. Now, on the flip side of that, back in 2016, '17, we started to see a lot of armillaria, and a lot of root rot issues, because all the rain we had. Usually, it's about a year or two behind. I'm still seeing the effects this year of all the bore damage from the past three years of drought.

I'm getting clients calling me on the phone saying, "Hey, James, have you seen all the dead trees on the side of the highway? What's going on? Can you tell me what's going on?" I'm like, "Well, emerald ash bore is here." It didn't get below freezing last winter, so those bores were feeding all winter. The amount of emerald ash bore just exploded in the Twin Cities. It's been getting bad, but from last winter, it's just hit that peak point of, in about 10, 12 years since it moved in. With that light winter, it's just been pretty, pretty bad.

Doug: You said that of, in consort with the drought, that the bores go crazy. I can remember we had a drought, a bad drought in Ohio in 1988. So many of our birches after that were taken by bores.

James: Oh, most definitely. Any type of flatheaded bore we've just seen explode over the last three years. You mentioned there, bronze birch bore, we're seeing signs of that everywhere. Two-lined chestnut bore in our oak trees. I'm talking, 150, 200-year-old oak trees. They're getting into severe decline, because of the fact of this drought. Then, the ash trees with the emerald ash bore too, they've just been really bad.

Bores were really bad. On top of that too, I saw one of the worst mite outbreaks for spruce trees I've ever seen last season, corresponding with that drought. I was seeing trees that I looked at, and I came back a month later, and literally a third of the tree was gone from mites. These are 30-foot spruce trees that have been in the ground for 30 years. We get out there, we can do some treatments on them, and we be proactive, and we can knock it back. It was pretty bad.

Doug: What are the strategies that can be implemented when we have these wild changes in weather?

James: I think, it actually goes back to a lot of different things that you've actually said in your podcast over the past few months. In drought years, watering your trees is really important. Mulch rings are really important. Then, being proactive, doing proactive treatments. Having a evaluation by an arborist on your property to look at your trees, and do these preventative treatments.

Are there different treatments we can do for two-lined chestnut bore, and ash bore? Yes, there are different injections, and insecticidal soil applications that we can do to help, do as a preventative, because that is really the key to be holistic about it, and look at all the different avenues. We could throw the book at it, we could inject it, we could fertilize it, we could do all the other stuff.

If the tree isn't getting water, if it doesn't have a mulch ring around it, we're only doing so much. There's a lot of different aspects you can do. The number one thing you can do is you can consult with a professional to go on your property to evaluate your trees, and to get a really good game plan ahead of the game, instead of behind. Because us trying to fix a tree after it's been eaten up, and half the canopy has been died back, it can be done sometimes, not every time.

I flipped around a couple oak trees with some growth regulators, and humates, and fertilizer, and injections, and let the tree survive. It still doesn't look like it looked like before. It's not the same, but the tree's still there.

Doug: Let me pick your brain a little bit about how you guys are dealing with emerald ash borer, because we came through here in Pennsylvania, we basically lost all our ashes. Is that what's happening there?

James: Luckily, we've learned, because we weren't the first people to get it. We actually do a lot of preventative treatments on ash trees. We do a lot of direct injections. Basically, if it's a really small tree, you can do a soil injection, but basically, most of those trees are either growing up to the point where you do a direct trunk injection of emamectin benzoate [unintelligible 00:10:41] or a insecticide to be a preventative. That happens every two years.

A lot of clients want to do that because they want to preserve their ash tree because ash trees, basically, replaced all the elms when all the elms died of Dutch elm disease, because the Twin Cities, they finally learned on the third round about, they just replaced a lot of the ash trees too in the Twin Cities that weren't treated with three dozen different species. Minneapolis is being progressive about that. Basically, treat or cut down, and replant, or the tree's going to die. That's basically what is going to happen.

Doug: Let's discuss the importance of diversity in our tree canopy.

James: When I'm talking with clients, I like to talk to them about a macro and micro level. I look at what city they're in, and then I just look at their property. If I look at their property and I notice, "Hey, your property is all acers. You've got a sugar maple, you've got a red maple, you've got an autumn blaze. Let's get maybe a swamp white oak in here. Let's get a hackberry, let's get a Kentucky coffee. Let's get some diversity on it."

Then, if I look at their neighborhood, and I also like to see like, "You know what? I haven't seen a single oak in this entire neighborhood. Let's plant an oak, so let's get some diversity in your property, and in your neighborhood." I'll also do that at the same time with, if I'm working with an association too that has 200 units, or something like that, where we'll look at their entire landscape and say, "What are you missing? How are we going to get diversity?"

I know the city of Minneapolis likes-- Their goal is to not have more than 15% of a family. They're not planting any more maples, because they've got 35% of the trees in Minneapolis are maples, just about-- Don't quote me on that, that's just a rough guess, but it's a high percentage.

Doug: Tell me a little bit about your job.

James: I've been at this job for about six years, been at Davey for eight, and I am in charge of all of the liquid services at our office. All the fertilizers, all the humates, all the insecticides, lawn care, and anything that has to do with that. I'm making sure we get good timing. Spring, I'm really busy. Basically, the season starts, we might do some oils in early Spring, and then we're switching into the fungi season.

We're doing crab apple sprays, we're doing rhizosphaeric needle cast sprays, we're doing fertilizers, and then it shifts into the middle of the season, where we're doing more insect control. We're doing injections, spider mite treatments, and other one-offs, smaller stuff. We get some like viburnum leaf borer, and we get other, not as common as like the big fungi season, but then also property evaluations.

Basically, my role would be, I have all of the services that we do for our plant healthcare. Make sure that all of the timings is done correctly, so we're actually-- Our treatments are effective. Working with technicians, training them on proper application, making sure that we're actually applying these products the correct way, so that the products are actually working.

We want to make sure if clients are going to spend money with Davey to protect their trees, that they're getting what they paid for. I'll also do-- Sometimes I'll, if some clients are unhappy with the services, or they don't understand what's going on, I'll talk with the clients and figure out what's going on, and create a solution, so they're happy with what we've done.

I sometimes do a little bit of consulting. It's not my full-time job, but I'll fill in for a sales rep if they're on vacation, or if for some reason someone needs to get out to this property right away to evaluate this tree, or this thing, I'll step up, and I'll do that too. Not every Davey office has a plant healthcare coordinator. It's different in different areas. We just found it's been really, really useful at our office to have one, because I can fill in the cracks, and make sure the ship is steering correctly on a really important aspect of our business.

Doug: One thing that I'm interested in are humates. We've brushed over the topic a couple times on the podcast. Tell me a little bit about why you're using them? How they work, and when they're best applied, and for what?

James: Yes, humates is something we've started in the past few years using, and we're applying them just like we would apply an Arbor Green deep root fertilizer. We're mixing them into the tank, and we're generally applying them in spring and summer. Basically, what a humate's going to do, is it's going to improve the soil structure. We're injecting it into the ground.

It's going to help the pore density a little bit, help the tree uptake nutrients better, and then, really, the tree is then going to be able to help mitigate diseases better itself. We're not fixing anything with the humates. Humates and phosphonates are really beneficial to soil structure. We do it part of our two-step program, where we're doing it in the spring, and we're doing it in the summer to help mitigate diseases, and drought stress by giving the tree these added beneficial nutrients that the tree can then take them, and then naturally defend itself better.

It's not going to fix anything. It's not going to stop a tree from getting these diseases and these blights and everything else, but it's going to help the tree mitigate, and help protect itself naturally.

Doug: Why is this job right for you, and what do you get out of it?

James: I get a lot out of this job, because I never really wanted to be stuck in a cubicle or office all the time, and I've always liked being outside. I ran cross country and track, I played soccer, and cross country skied, and did all this stuff through high school, and a little bit in college, and I've always enjoyed being outside, and I just was looking for something that would allow me to do that.

I think, if anybody is interested in being in nature, and then also likes to actually understand science and everything like that a little bit, I think it's really good, and also, I enjoy the fact that if you're an arborist, you have to have a bunch of different aspects. You kind of-- If you're growing up in the field, you got to go be an athlete.

You got to go be able to carry brush, or a chip, or climb a tree. You also got to go be a little bit of a scientist. You got to go be able to diagnose things. You got to go always be able to learn, and then you got to go be a little bit of physicist too, because sometimes if you're out working in the field, you have to be able to understand if you're going to rig this branch down, where it's going to go.

You get to really be a well-rounded individual, and you get to do a lot of different things, which always really enjoyed being able to not just do the same thing every day, and every day is a new challenge, and every day is a new adventure, because you're always dealing with trees, and trees are difficult to learn sometimes, and they're difficult because they-- You think they're going to do one thing, and they do another thing, so then you come up with a solution for that.

I just think it's a really good fit for me in that regard, because I've always liked challenges, and always liked to look at things in a different way, and I didn't want to be stuck inside on a computer all day. [chuckles]

Doug: All right, James, that's great stuff. You don't know how often I hear from the people that I interview, the first thing is like, "I just-- My love of the outdoors," but there's a lot more than that. We know that for sure. Thanks very much for your time, and it was wonderful to talk to you.

James: All right, appreciate it. Thanks for having me on, Doug. I really appreciate your time, and really enjoyed talking with you.

Doug: All right, thanks again.

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We've talked to lots of arborists over the last few years about the shift in weather patterns, and how it's affecting trees. Now, tune in every Thursday of the Talking Trees podcast from the Davey Tree Expert Company. I am your host, Doug Oster.

Do me a 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 to 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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