Travis McDonald from Davey's South Minneapolis office shares advice on tree care and planting in extreme temperatures, from heat waves to cold and snow.
In this episode we cover:
To find your local Davey office, check out our find a local office page to search by zip code.
To learn more about watering, browse our Watering blogs.
To learn more about mulching, browse our Mulching blogs.
To learn more about the shifting hardiness zones, visit HardinessZones.DaveyInstitute.com.
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!
Travis McDonald from Davey's South Minneapolis office shares advice on tree care and planting in extreme temperatures, from heat waves to cold and snow.
In this episode we cover:
To find your local Davey office, check out our find a local office page to search by zip code.
To learn more about watering, browse our Watering blogs.
To learn more about mulching, browse our Mulching blogs.
To learn more about the shifting hardiness zones, visit HardinessZones.DaveyInstitute.com.
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!
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 Travis McDonald and he's a district manager for the Davey Tree Expert Company near Minneapolis in Minnesota. Today we're talking all about growing in extreme weather conditions. Travis, these crazy weather shifts that we're seeing are over the last several years.
Travis McDonald: Yes, absolutely. It's the temperature swings and the climate changes that have taken place have shown a lot of stress on many different trees that have been around for 100-plus years are now really starting to see signs of decline and really their environment hasn't changed in regard to their location. It's just lack of water and high heat temps throughout the summer. A lot of boulevard trees we're seeing severe decline because of the heat has drastically increased along the road temperatures and so forth and then lack of water. It's so sparse in between rainfall, so we had a very dry summer last year.
Doug: Nobody that grows plants wants to hear about a really dry summer, that's tough, and when it comes to irrigating trees that's no easy task.
Travis: It definitely isn't, but there are some pretty fairly easy ways to monitor your trees and make sure that they're getting ample water. Whether you buy a probe that can do a deep root watering that is extremely beneficial. We've had people that been neighbors side by side with the same type of species of trees and one wanted to follow a watering recommendation that we provided to them.
Throughout the growing season, it was a night and day difference of the health of the overall tree canopy from the person that watered weekly to the person that didn't water at all other than running irrigation for their turf but not doing a deep root watering and that tree showed severe signs of stress early leaf drop in the twig elongation for their growth was very minimal throughout that growing season.
Doug: The USDA released a new hardiness zone map, did yours zone change?
Travis: It did change. We actually changed down to Zone 5 and Zone 4 a little bit further south of us where it actually gives us more options to plant different type of species of trees, but we don't know if that's going to swing back around so people have to be really diligent on what type of plants are going to plant in their yard for longevity and whether the polar vortex rolls back in and we see severe cold temperatures just in one season that can wipe out a lot of those trees.
Prime example a few years ago, we had we've been dealing with emerald ash borer and so the city of Minneapolis has been planning different species of trees to try to not create a monoculture, and with that, they planted a lot of sycamore, and London plane trees and they were starting to get to be pretty good size, but then we had a polar vortex that came in and actually, killed them all off so we have to really be careful on how we choose our plantings until we really start figuring out what climate are we actually going to be in.
Doug: Let's talk a little bit more about the summer dry hot.
Travis: We had a lot of 100-plus degree days and dry was an understatement. We got a little bit of rainfall, but the rainfall would be hard and heavy and fast and that's exactly what you don't want and it would be so intermittent and sparse to where we would go four to five weeks without any rainfall. With that, those trees really showed signs of decline and stress, but the people that were watering properly, their plants look great.
Doug: Let's talk a little bit about watering properly. First off, what time of the day should we be watering our trees?
Travis: Early morning or late in the evening, that is the best practice. Whatever fits your schedule if you can do it early in the morning and do a deep root watering, it's going to be great that plants going to have enough time to absorb that moisture to where it's prepared throughout the heat of the day or that evening after a long hot day that applies water back into the tree.
Doug: You mentioned the probe, is that something that a consumer could get and put it on their hose and use it?
Travis: Oh, yes. They're all over the place and go online to we'll say Amazon for instance, you can find deep root watering probes for a very reasonable price and whether you want to go out there and enjoy the evening and do a deep root watering and move that around but you're going to do a deep root watering that might take up to 30 to 40 minutes on a particular large tree. A quick 10-minute spray with a hose is not going to cut it.
Now, if you don't want to invest in a probe, the best solution that I tell everybody is take a garden hose drag it up to the trunk of the tree, turn it on to a slight trickle about maybe the size of a pencil and let that run for at least an hour. You can maybe move it to one of the other sides, but eventually, that's just going to do a deep root watering and keep it fairly close to the root system of that tree and that drip line.
Doug: It's no big deal, when I water that way, I'll put the hose down I'll go do something else in the garden do this do that, and then come back move it again. Small trees need more water than the big trees or everybody needs water?
Travis: That is a misconception and everybody thinks new trees need a lot of water to really get established, but those old trees need even more water. Think of their canopy size and the elements that they've been undergoing for many, many years try to keep them as healthy as you can you'll have less disease and insect problems with just proper watering that would go a long way.
Doug: With the hot summers that we've been getting, let's talk a little bit about mulch and that is a big topic on this podcast, we talk about it almost every other week and so it's an important part of growing trees, especially in these extreme conditions where that's going to hold some moisture in for you and make that tree a little happier right?
Travis: When it comes to holding moisture to organic breakdown matter to actually keeping the root system actually a little bit cooler. If you have turf right up to the trunk of your tree, what you're going to find is that that root system is actually heating up to the point where it's drying out the soil a lot faster. Now, think of trees in a native setting where they have organic leaf matter and they have lots of other volunteer trees growing up around them, their root system has more of a shade canopy to help maintain that moisture in the soil.
In urban environments, we might just have standalone one or two trees, and that sun is just beating down to the point where that tree doesn't really have any more protection other than its own canopy so that soil dries out a lot faster. Mulching, as an arborist we can't recommend it enough, now you can mulch too much. If you're mulching just for aesthetic purposes and you're rejuvenating your beds, you need to make sure that you're not piling on too much mulch to where you are smothering the root system or putting it up around the trunk of the tree where it's actually confusing the roots to where you can start having stem garden root issues around the bases of trees.
A lot of people call it volcano mulching, but there's a real science to mulching appropriately for trees and the hardest thing to drive home to people in urban settings is they like the grass they like the aesthetic look, but they also really want to take care of their plants and trying to coach them on letting them know if we just added a mulch ring around this tree, it would decrease the stress of this plant and help maintain moisture through the really peak hot day.
Doug: Travis, let me tell you this, the son of the host of the Talking Trees podcast sent an email to me and said, "What do you think of that rubber mulch? My head just about exploded when I got that message because what they're thinking, what he's thinking as a new homeowner, how long do I have to put this down once? Just tell us all the negatives of putting that rubber mulch down, because there are many. [laughs]
Travis: Yes, it's going to heat up, right? It's actually, think of rubber sitting outside in the sun, how much that absorbs heat? Furthermore, it has no beneficiary nutrients that it's providing to the plants. It's strictly just aesthetics at that point. It's no different than putting landscape rock around through all your beds because you want to not have to worry about, either weeding or, touching those beds back up every year to keep things looking aesthetically pleasing.
Putting rocks around trees and landscape plants, you're actually just heating them up even more and drying the soil out. Think of putting your hand into a native area, like along the side of a road where there's a bunch of tree canopy, feel that soil, and then go touch a concrete or, an asphalt surface and tell me what the difference is, and you're going to see a huge difference. Putting rocks around your landscape beds, I don't recommend it as an arborist.
Doug: Well, I had a friend do that too, and I didn't see it until it was done. I wasn't going to say a word. I was over there at the end of the season, and he showed me these trees that are struggling. It's full sun and again, he's thinking, "Okay, I'm never going to have to weed again. I'm putting down a landscape barrier, then I'm putting these, and they're big rocks, like three inches big."
I'm just thinking to myself, "The next person that owns this house, what a pain it's going to be to get those rocks out of there?" If I told him, he would be like, "You mean I spent the entire summer building these rock beds and the trees and shrubs are miserable." The other thing, I know there's going to get weed seeds down in there above those rocks. Then you're going to--
Travis: Absolutely, it's inevitable, right? Something always requires maintenance when you're trying to have an urban environment being controlled. Everything's going to require maintenance. It's just like, "Well, the maintenance that I do, what's going to be the best benefit for the plants that I want to keep around?" A lot of that just comes down to basic maintenance practices. Watering, if you're not having large mulch rings around the trees, all the way to the drip line of the canopy, substituting nutrient deficiencies by doing deep root fertilizations, putting some organic matter back into the soil.
We deal a lot with soil compaction because we're running large mowers over turf consistently and just packing things down. We're never building an organic layer. Therefore, you need to do a lot of soil care, whether that is adding biochar to the existing soil to allow for air and nutrient holding. There's many different things that you can do to really keep these plants healthy in urban environments. It's just, what are you willing to do? Do you really love your trees that much or do you just saying that, but you've got to provide care to them? It all starts with just basic maintenance.
Doug: I've heard from arborists over the last couple of years talking about biochar. How do you guys use it?
Travis: When we are doing, a new planting, let's just say, and somebody wants a new tree in their front yard. Well, 90% of the time, when we go out and dig in anybody's front yard, there's compacted soils. It's a clay base, very little organic matter on top. They got a three or a four inch maybe layer of topsoil. What we end up doing is we always dig the root ball, the whole of the plant, one and a half times the size of the root ball. When we do that, we make sure we do not glaze any of the surrounding areas of the hole that we dug.
We try to loosen it up a little bit. Then we do a proprietary mix of compost, biochar, and topsoil, along with a little bit of fertilizer amendments. With that, that really is what's going to take off and establish the root systems of that newly developing plant. Biochar, it doesn't break down. You can't compact it. Therefore, when you're putting it into the soil, that's going to help keep airspace to allow for those roots to breathe and obtain and hold more moisture because it has an area to actually sit.
We use biochar for those, but we use biochar for large tree canopy renovations where we go in and do an entire canopy restoration around the root system of this plant and mix in compost and biochar to actually give it some organic matter, but also allow for, loosening of compaction. There's other ways you can use biochar as well. You can do a powdered biochar that will help with when you're doing a deep root fertilization, and that provides a lot of value as well if you're not looking to invest heavily into doing an entire soil care project at your home.
Doug: We've talked about the extremes in summer, tell me a little bit about your winter. When I think of Minnesota, I think a tough winter every year. Have you seen changes in winter as we have here in the East?
Travis: Yes, don't get me wrong. I'm originally from New Hampshire and I thought, we always had pretty extreme temperatures and hard winters. I moved out here to Minnesota and why don't you just double that? It's like moving to the tundra. It's got its benefits for sure, but the weather, we've had a lot of really cold winters the last couple of winters. This year, it's going to be in the 60s tomorrow. We're looking at, the second-- no, first week of December. With that, we would already have snow on the ground by now.
Things are dry even now and the temperatures are fairly mild. I don't really know what type of winter we're still going to endure. That's helpful for the plants for sure. Those really cold vortex winters, really take a toll on the plant's health, especially if they go into the fall with drought stress on top of them. The best thing you can do is water all your plants right up until the ground freezes.
Doug: Yes, that's exactly what I was going to ask you about. Even though we talked extensively about watering, during the heat of summer, very important to get those trees ready for whatever's coming in winter, which we don't know. Here in the East, we had mid-December 40s, 50s, and then dropped to wind chills minus 22, which was tough on the plants. Those trees that have been watered and are ready for it are going to do better than those that are under drought stress, right?
Travis: 100%. Especially with evergreens, you'll get a lot of winter desiccation if they're not actually hydrated well before they actually go into dormancy. Everybody thinks like the minute that leaves start dropping on trees, then we're done caring for them in the fall. Those trees' root system is when it's actively growing right up until the ground freezes to prepare itself for next spring and water them. Just because they don't have leaves on them, they still need water.
There's still activity taking place. Evergreens, especially, water those right up until the ground freezes. Two nights ago, I was watering my evergreens. This is December, you usually shut off all your spigots and pull on all your hoses. Well, I'm pulling my hoses back out because things aren't frozen yet. We're really not getting any type of moisture in the soil so I've been watering my evergreens.
Doug: Travis, I'm going to leave it right there. I really appreciate all this great information. As we've seen the changes in weather and these extremes coming, we want to keep our trees going strong because we love our trees.
Travis: Great, we do.
Doug: Thanks again for your time. I'm sure we'll talk again.
Travis: Absolutely, Doug. Thanks a lot. We'll see you later.
Doug: Tune in every Thursday to the Talking Trees podcast from the Davey Tree Expert Company. I'm your host, Doug Oster. Do me a big favor, subscribe to this podcast so that you'll never miss a show. If you've got an idea for an episode or maybe a comment, send us an email at podcasts@davey.com. That's P-O-D-C-A-S-T-S at D-A-V-E-Y dot com. As always, we'd like to remind you on the Talking Trees podcast. Trees are the answer.
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