Talking Trees with Davey Tree

How to Protect Trees & Plants from Rock Salt Damage

January 26, 2023 The Davey Tree Expert Company Season 3 Episode 4
Talking Trees with Davey Tree
How to Protect Trees & Plants from Rock Salt Damage
Show Notes Transcript

Kevin Sproule from Davey's Edmonton, Alberta, office shares advice on how to protect your trees and plants from rock salt damage, as well as how to determine if your tree has experienced salt damage.

In this episode we cover:  

  • How to keep plants safe from salt (0:45)
  • Keeping salt away from the base of trees (1:41)
  • Watering (2:38)
  • Determining if a tree has salt damage (3:15)
  • When to call an arborist (3:58)
  • Fertilizing (4:28)
  • Physical barriers (6:37)
  • Tough winters (7:37)
  • Trees that are more tolerant to salt damage (8:04)
  • Trees that are more susceptible to salt damage (9:01)
  • How Kevin started his career (9:27)
  • Climate in Edmonton (10:33)
  • Free consultations (12:56)
  • How often will an arborist visit a property? (13:42)
  • Relationship with clients (14:22) 

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

To learn more about how to protect your trees from rock salt, read our blog, How to Protect Trees from Winter Salt or Rock Salt Damage.
To learn more about ways your property may be experiencing rock salt damage, read our blog, How Rock Salt May Be Affecting Your Lawn.
To learn more about salt tolerant trees, read our blog, Salt Tolerant Evergreen Trees (By Zone and Region).

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

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


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 this week by Kevin Sproule. He's an assistant district manager, Edmonton, Alberta, Canada for the Davey Tree Expert Company.

Today we're talking all about salt. Kevin, we picked the right day to do this because out here in the East, we are getting freezing rain and snow, so I'm going to have to apply some product out there. What's the first thing that comes to your mind for keeping these trees and shrubs and other plants safe from salt? Because we know those two things don't go together.

Kevin Sproule: The first thing that comes to mind is if you are going to spread salt, try and choose one that has calcium chloride. This is a little less harmful to plants than the generic sodium chloride you'll find in most rock salts. If you are going to use sodium chloride, try and mix in something that will help with the traction, so you could put in some sand or some sawdust, maybe some smaller wood chips, and this just helps aid with the traction so that you're not having to put down as much salt on the ground.

Doug: I'm using a product that has some magnesium in it, where I've read that it's better for pets, better for the plants too, but it's still corrosive, it's still going to cause problems when it interacts with the roots of a tree or shrub. Some other ideas for us to keep the salt or product, whatever it is, away from the base of the tree?

Kevin: There is some cultural practices that you can do, maybe some good habits to start which is something as simple as just not piling as much salt on the base of the trees. Maybe you can change the way that you're shoveling, I know myself I've tried to alter the way that I shovel out my front walk and maybe putting that snow out into the road as opposed to back towards my lawn where the trees are, so something to think about when you're out there shoveling is just where is this salt going to be in the snow when it melts in the spring?

Doug: I'm trying to use the least amount as possible, not only for the plants, not only for the pets but also for the surface in which that I'm throwing this stuff down on which it can be corrosive against sidewalks and the long asphalt driveway that's getting torn up on a bad winter. Other things to think about when we're talking about salt and trees. Certainly, when we get to the spring, at some point we can help out with water, right?

Kevin: Yes. In the spring, when the snow is melting, a good thing you can do is basically flush the soil. You can put out a slow drip pose, maybe underneath your trees, or if you have an irrigation system, maybe turn up the amount of water for the spring. What you're doing is you're literally kind of flush that salt down through the soil and away from where the roots are, so they won't uptake it.

Doug: Is there something that, like, when we get to the spring, if I look at a tree, is there a way for me to tell if it's been damaged by salt? Could it be a lot of different things that could be the problem when I get to the spring?

Kevin: When you get to the spring, typically, salt residue will turn conifer trees or evergreen trees pale green, and you'll have some yellowing needles. On deciduous trees, the symptoms are a little less obvious. You can have a little bit of dieback in the canopy, so some of the branches are starting to die off around the top of the tree, the bark can have a bit of a discoloration, but those are a couple of symptoms that you'll typically see from salt damage.

Doug: Anything else I should think about in the spring when I'm thinking about if we did have a bad winter and I did have to use a lot of product, what I should be doing as far as looking at these plants and making sure that they're happy?

Kevin: Yes. What I recommend is to call your local Davey office and we can come out and have a look and do a diagnosis and try and determine if this is salt, it may be some other issues that were there in previous years, but I would just call your local arborist at Davey Tree, we can come out. One thing I would recommend is maybe after the watering is do a fertilizing just because the salt will suck up that water and it prevents the trees from really getting all the nutrients that they can.

Doug: We talk a lot about fertilizing here at the podcast because it's one of the things that homeowners don't do it the way they should be doing it, and I'm guilty too. I do have my Davey arborist coming and telling me and helping me out with certain trees. Do you guys use the same type of system where you've got a probe that goes down in the ground with a liquid fertilizer? Talk a little bit about that.

Kevin: Yes, absolutely. It's the same system we use up here in Edmonton. We have our own patented fertilizer and it's applied with a probe that goes down about a foot down into the ground, and then it shoots out with high-pressure water in four directions, so you're getting the benefit of the fertilizer, of course, but then with that high pressure, it's actually breaking up the soil components in the ground and helping reduce any compaction that you may have there, which is a common thing really.

Doug: I've seen the results and so if you could talk a little bit more about fertilization. I'm telling you I had this Cherokee princess, I think it is dogwood, and it was just struggling along. It would throw some blooms, but once they started the fertilization process, I got a real happy tree with lots of buds and I'm going to see lots of flowers this spring.

Kevin: That's great. I'm glad to hear it. One of the reasons why fertilizer is so important is that in an urban setting, trees are not getting the natural nutrients that they would get from fallen leaves or old dead trees that have fallen down that recycle those nutrients into the ground, so in an urban setting, you're not typically getting that. A lot of homeowners will clean up the leaves and you're not having those old trees fall on your lawn, and so that's where the fertilizer comes in, and it delivers three of the macronutrients that trees and shrubs are most looking for, nitrogen, phosphorus, and potassium.

Doug: Back to salt, is there anything else you can think of that I haven't asked you about? When we're thinking about salt in our landscape, maybe lawns, and it's usually just the edge of the lawn or the edge of a sidewalk and such. Physical barrier, is that possible or not really?

Kevin: That's not a bad idea. If you could put in some physical barrier, some landscaping product, maybe that prevents the snow from getting over to that area, like what I was saying before if you could try and shovel the snow away from your plants, if you can get away from your lawn completely, that would be great, and then do a good rinse in the spring. If you're in a climate which allows you to water in the winter, let's say you have a warmer break in the winter, it's a good idea to rinse. In the winter up in Edmonton here, we're pretty much frozen for six months, so that's not really an option for us, but in a warmer climate, definitely.

Doug: Do you see a lot of salt damage when you're driving around? If you've got a tough winter like that.

Kevin: Yes. We do for sure. You'll see a very noticeable burn along the edge of the turf and the grass. If there's trees that are right close to the sidewalk or to the road, we'll see some of those symptoms I was talking about before, yellowing needles, some dieback up in the canopy, but it's an issue to be watching out for.

Doug: Are there any trees that are super tough against salt that you would recommend for a spot? Let's say that there's a spot where when you do have a bad winter, the only way to get it clear is to use some product. What would I plant there if I was thinking something that just not quite as sensitive to salt, if there is anything?

Kevin: Yes. Good question. There may be situations where you're looking to plant a tree, or you have a tree that's in an area where you just can't get the salt or the snow away from. One species, a deciduous species is oak. Oak is quite naturally salt tolerant, and so red oak, white oak, bur oaks are a good option, and then for your evergreens or coniferous trees, Austrian pine is quite salt tolerant, and also Colorado blue spruce does well as well.

Doug: Any things that don't even think about it, don't even think about planting this because the salt's going to kill it for sure.

Kevin: I would say probably poplar species, something like that. A spruce tree I've noticed as well too in the landscape doesn't do quite well. You'll definitely notice some yellowing needles in the spring if it has some salt damage.

Doug: Tell me a little bit about how you got into this. Why is this job right for you?

Kevin: Oh, well I got into this job, I've been here about six and a half, seven years. I went to school for forestry way back when, it feels like another lifetime ago, but I went to school for forest technology. I got my two-year post-secondary diploma from our local institute of technology, and then I worked for a little bit doing some surveying, and I was working out of town quite a bit. I still loved the tree work, but I was hoping to get something that I was closer to home, and so I stumbled upon Davey Tree that does tree services but local here in the city so I can be at home every night. It's a perfect blend for me and my family.

Doug: Tell me what you get out of your job. What's the best part about it for you?

Kevin: I love the trees, people often ask me about it. I love the trees. I just love talking to people about their trees and I feel honored that they invite me into their home and share their emotional experience with their own trees and shrubs because there is a bit of an attachment there.

Doug: What's your climate like up there as far as your tree planting times? I always like to pick brain of an arborist on some cool trees that they love to plant in their area that maybe aren't planted as often as they should be. We always say, "right tree right place" but arborists always have something in their mind and in their back pocket that they hope they can get to plant in their area. First, talk about the climate. When is planting season for you?

Kevin: Planting season for us, which start typically I'm going to say in April or May and go till about October, maybe November, depending on the year. We do have a typically shorter season than many climates just because we're so Northern and we just have a short spring and summer basically.

Doug: Then how about some things that you love to plant when you find the right space for them?

Kevin: I am particular to the bur oak tree. Like we were saying before, it is salt tolerant and it's a really nice tree. We typically don't have many oaks up here. It is one of the oak species that does well. I also enjoy linden trees, little leaf lindens. They seem to do well up here and I quite like the shape. They almost grow in a Christmas tree shape but they are deciduous trees. It's a quick way for us.

Doug: Is it real fragrant? Am I thinking of the right tree?

Kevin: Yes. I believe you're right.

Doug: Yes, because someone talked about a linden before on the show and I remember there's this gardener that I knew that worked at an amusement park, where they had a whole bunch of lindens. She said it was so fragrant, it was too much. She just couldn't take it.

Kevin: Right, you got to throw in another species there.

Doug: Yes, definitely. Also, is it true that when you do keep your trees healthier during the season, they're going to do better in the winter if there's salt problems there?

Kevin: Yes, absolutely. In general, for trees, when they are healthy and happy, they can withstand basically what nature throws at them. A tree will have a certain amount of energy for certain things, for growth, for defenses. If you can keep that tree healthy, they're just better to withstand something else. It's much like a person, if you're rundown, you're more likely to catch a cold or something like that. We recommend fertilizing, keeping your tree watered, some mulch, just general things to keep it healthy and that should help prevent salt damage.

Doug: One thing I wanted to remind listeners of is that if you do request a Davey arborist to come to your property, they'll come and take a look for free, right?

Kevin: Yes, absolutely. It's a free consultation for us to come out and have a look. A lot of times customers will have us come out and have a look at a particular tree problem but while we are there, we can notice other issues that are there potentially. It's always a good idea to give us a call and yes, it's absolutely free.

Doug: You know how many times I've heard an arborist told me that story where they come to look at one specific tree like Cherokee Princess Dogwood for instance and then see a giant oak over my garage that is about to crush my car. Thank goodness they did because now the tree is gone. How often do you like to go to a property once you get clients on board?

Kevin: Once they're on board, there's the initial consultation and then I often will go back with the crew that's going to be doing the work just to walk them through and meet up with the customer again. Then typically, we'll do another follow-up afterwards, just to make sure everything went well and their trees and shrubs are happy and healthy.

Doug: Then as the years go on, I like to have my Davey arborist come at least once a year. I have a declining oak forest, so I'm seeing him at least twice a year but that's okay. It's keeping everything safe and I'm learning a lot about my trees. Tell me a little bit before I let you go about this relationship that you put together with these clients over the years and what you get out of it and what you want them to get out of it.

Kevin: Well, one of the things we want to do is create a relationship so that they know that we are taking care or we aren't as invested in their yard as they are really. One of the things I love about this job, like I said is going out and seeing the trees and talking to people about their trees and shrubs. I almost take it on as personally as if it's my own yard when I see them regularly, I do enjoy that.

Doug: All right, Kevin. Well, thank you very much for all that great information. Perfect timing, as I said out here in the East because we are applying some of that salt product or something similar. I appreciate your time. I appreciate all the great information and we will talk to you again sometime.

Kevin: Thank you so much, Doug, and we'll talk later.

Doug: Tune in every Thursday to 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 one of our fun episodes. If you have some ideas for the show or some feedback, I'd love to hear from you. Send me an email at That's As always, we like to remind you on the Talking Trees podcast, "Trees are the answer."


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