Zane Raudenbush, turf and herbicide specialist within the Davey Institute, talks all about how to get the best lawn to celebrate Smart Irrigation month this July. In part one, Zane talks about species of grass, irrigation mistakes and best practices, and more.
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 grass species and identification, read our blog, What Type of Grass Do I Have?
To learn about the best times to plant grass, read our blog, Best Time to Plant New Grass Seed: Pros and Cons for Each Season.
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Have topics you'd like us to cover on the podcast? Email us at podcasts@davey.com. We want to hear from you!
Zane Raudenbush, turf and herbicide specialist within the Davey Institute, talks all about how to get the best lawn to celebrate Smart Irrigation month this July. In part one, Zane talks about species of grass, irrigation mistakes and best practices, and more.
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 grass species and identification, read our blog, What Type of Grass Do I Have?
To learn about the best times to plant grass, read our blog, Best Time to Plant New Grass Seed: Pros and Cons for Each Season.
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
Have topics you'd like us to cover on the podcast? Email us at podcasts@davey.com. We want to hear from you!
Doug Ouster: Welcome to the Davey Tree Expert Company's podcast, Talking Trees. I'm your host Doug Ouster. Each episode showcases one of Davey's certified arborists sharing advice with everyone about caring for your trees and landscapes. We'll talk about everything from introduced pests, seasonal tree care, [unintelligible 00:00:20] damage, how to make your trees thrive, 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 Zane Raudenbush. He's a turfgrass and herbicide specialist for the Davey Tree Expert Company. It's part of our smart irrigation episode. Zane, we're into July. We're talking about watering. Let's talk a little bit about the right way to water our lawn. That's a lot of area to water, though. Start off there. How do we get water to the grass?
Zane Raudenbush: Yes, this is a great topic. You know, from my standpoint the questions are starting to funnel in from people out in the field about what is the directive that we should be telling our customers to water properly. It can be complicated but can also be somewhat simple, Doug. I think the reality is to recognize that water use is going to change throughout the season and as we start to get into the summer months.
One, the temperature is elevated and two, mother nature just often the time between rainfall events starts to be extended and just the amount that we get is reduced. Soil moisture becomes limiting. How do you begin to tackle that I think is-- I first start with what are your expectations? I think that that's a really key place to start is what are your expectations for your property? One of the things that I see sometimes is that the expectations can be a little, I don't want to say unrealistic, but you could use a lot less water if you were just willing to maybe accept or tolerate a reduction in color.
Potentially, a little bit of reduction in quality, we see, can really result in a lot less water use. Close to 70% in some of the studies that are published out there. I think that's the first place is what are your expectations for your property? If you're someone who expects it to be green all the time and really to be pretty plush, you are going to have to be very, very judicious in terms of the amount of water that you put down and when you put it down.
If you're someone who just says I just want to maintain decent quality, we would see that, well, then maybe you can get away with some spot watering in between when mother nature doesn't. I'm dancing around your question a little bit, but I think it's important to get that out there right away, that let's face it, these plants go under a lot of stress in the summer months. Honestly, I see sometimes people with irrigation systems would do themselves a favor by not running them, that they kind of exacerbate some problems through the use of their irrigation system where if they just wouldn't have used it at all, they actually would have resulted in better quality.
Where do we go from here? It depends. Do you have an in-ground irrigation system? Are you moving hoses around your property to irrigate? If you're like me who'd be a hose dragger, and I'll be totally honest with you, I don't water my lawn. I'm that person who does accept that there will be some reduction in quality.
Doug: Yes. Well, I think that's a very interesting point about what you want out of your lawn. In my case, I just want it to stay alive, but if the culture of your neighborhood is such that every house has this nice lawn, that's where I think the water usage is crazy. You said something interesting there about your grass, that you're not watering yours, but you mentioned other species in there. Talk a little bit about that. That's really interesting to me.
Zane: Yes. I lived in Kansas for six years while I was getting my master's and PhD at Kansas State University. In Kansas, one of the predominant turfgrass species that they use is turf-type tall fescue. Where we live in the Pittsburgh Ohio area, you will also see turf-type tall fescue, but you'll see a lot of perennial ryegrass, Kentucky bluegrass. You see a lot of fine fescues. One of the things that turf-type tall fescue does well is it has really good heat tolerance.
Some of these grasses that gets really hot will go under heat stress and you'll start to see a lot of necrotic leaves and they're just not going to tolerate that. Also, tall fescue is a really deep rooter. It can produce much deeper roots than a lot of the other turfgrass species can. It has Achilles' heels, though. It's a bunch-type grass, so compared to something like Kentucky bluegrass that can produce rhizomes under the soil that help it spread and help it recover from traffic or dog urine stains or whatever it might be, turf-type tall fescue is a bunch type grass, so if you would come in there and divot it up or remove turf, it's not going to fill back in.
That's one of its Achilles' heels and it's susceptible to a disease called brown patch, but in the summer months, it maintains really good color much longer than those other species that I mentioned will from my experiences. That was something that I did. I went through a renovation last fall and turned the stand over and made it pretty much all turf-type tall fescue. The color is there. When you look around and my one neighbor has a fine fescue yard and it looks phenomenal in the spring months.
It's a gorgeous lawn but right now it's lost its color. It looks a little rougher, but it will recover when the rainfall comes back. Definitely, things about species are an important piece and that's a whole more holistic conversation. Something our industry is looking very closely at actually is putting the right plant in the right place and managing the expectations that might come along with it. For instance, Kentucky bluegrass, it's my favorite grass. It's a phenomenal grass, great color, great density, the recuperative ability, but its mechanism for going through drought and heat conditions is it goes into dormancy.
This is a grass that can go dormant, that will lose its color, and then when the rainfall and the temperatures are more conducive, will come out of this dormancy, and really quite amazing how much recovery can happen there. The differences in the species certainly can really influence what you might expect to see on your property.
Doug: Can I have a bunch of those different species in there? It sounds great, the one that you have. What is it called? The tall--
Zane: Turf-type tall fescue.
Doug: Then, that fine one sounds great for the spring and then Kentucky bluegrass. Can I mix these all together or it doesn't work that way?
Zane: Yes. You can mix together and it's often a recommendation. It was actually what I attempted to do in my lawn a little bit was a polystand, so it's always good to have-- When you're going to plant grass, there's a couple different recommendations. One, there's what's known as cultivar. My grass, although I say it's turf-type tall fescue, there's actually five different cultivars of turf-type tall fescue.
Those are unique genetic individuals. An idea there would be if one of those individuals is really susceptible to disease like brown patch, we're not going to lose the entire stand or whatever it might be. You're hedging your bet there. Then what I attempted to do was, I actually seeded that with a mixture. I added 10% Kentucky bluegrass by weight to the mixture because I was hoping to get some established. The problem with Kentucky bluegrass is that it's a poor establisher. It's hard to get established from seed.
If you look at my yard and get down there and look at the plants, it's all turf-type tall fescue. To answer your question, what plays well together? I don't think the verdict is out there, but you do have to be careful. Some of these plants are very susceptible to similar diseases, leaf spots, epithelium. Can you mix them? Yes. You also have to be careful about the differences in the leaf color and texture. For instance, you talked about the fine fescues like my neighbor has. That's a grass that really does great in the shade.
I don't typically recommend the use of that grass in a full-sun area because it will lose color in the summer months, but in the full shade, there's no better grass. In low-maintenance areas where you don't want to mow there's no better grass, but it has a very fine leaf texture. It looks like almost a pine needle fascicles, that they're very thin blades and then you get them mixed with a blade that's coarser textured, it's been my experience that a lot of customers don't-- It's a lack of uniformity.
There's a lot to consider, Doug, but to answer your question, they can be mixed and if you would look at some of your local extension publications you'd be able to find what those ideal mixtures are for your area.
Doug: All I want is green. I don't care about leaf, this, that. I just want green, but talk a little bit about having your job and then having neighbors on either side with their lawns. Are they always asking you like, "Hey, how come yours is green now and mine isn't? You're not watering, what's going on with all this?"
Zane: Yes. I get a lot of questions, friends, families, and neighbors. I always joke with people. That's the only time I get text messages, it seems like, from most of my families, when there's a weed or something that needs IDed in their yard. You do get a lot of questions from neighbors. It's always interesting, actually, to see what some of the perceptions are, Doug, in my field, to listen to what people think and believe, and where they got that information from.
It's always interesting to take them down the realm of where I'm headed. I'm all about trying to create a sustainable landscape. I want the color too. It's my profession. I want my property to show that I have that expertise, but at the same time, I have a family with kids and my time is spent doing other things. I'm all about trying to get my landscape to be more sustainable and I do that through great cultural practices of the proper mowing height, the proper mowing frequency, addressing soil issues, as I mentioned, trying to get the ideal species, what I felt like was correct for my yard.
There's a theme sometimes when I go, so it's not uncommon for me, where we have customers whose-- I shouldn't say it's not uncommon. It does happen, unfortunately, where we have customers whose properties aren't up to what they want it to be, to their standards. We go visit those properties and you sometimes just see some inherent issues, that there might not be any topsoil. That's one of the most common things I see in the urban landscape is that people build houses and what those contractors do is they come in and they scrape off all the topsoil into a pile, they build your house, and they try to respread that topsoil as evenly as they can across the property.
It's never perfect and there are places, literally, where there is no topsoil, and turfgrass plants really are not going to grow in what we call subsoil. It's pretty much devoid of any nutrients. The physical properties aren't conducive. What do you do for a customer like that? Talk about soil modification, but ultimately, to fix that problem, we can't fertilize, we can't irrigate our way out of an issue like that. I'm always trying to get people to see that if there is a reduction in quality, what is the true underlying cause. I think too often people are very quick to pull a sprinkler, or to fertilize their way out of a problem that really could be related to a soil or a shade issue.
Tree shade is a really difficult place to grow quality turfgrass under because the light that reaches the turfgrass canopy has already had a lot of the energy taken out from the tree leaves. Those are the things that I focus on and try to educate people that, one, I sometimes see in some of these properties to let someone know, like, "You have a really challenging property to grow quality turfgrass." A beautiful property, it has all these different things, but you have to have a little bit of a give and take. If you have a property that's got 15 100-year-old pin oaks on it, that are gorgeous trees, maintaining a plush lawn underneath of that, that's where the expectations need to be managed a little bit.
That's where we might say, "Let's come and introduce the correct species," if they planted a bunch of Kentucky bluegrass that's going to have powdery mildew issues, and we could go towards a different species. To answer your question, I just keep coming back to, culturally, what can we do to put the plant in the best position possible to maintain good quality?
Doug: Let's get back to our watering.
Zane: Yes. We've digressed there a little bit. We'll get back to it.
Doug: I think we're going to talk for a long time about lots today because we've got a lot of stuff to cover. I love this information. I'm a hose dragger, too. Is there a specific if we're going to water that lawn. Let's say we've got a decent lawn, we've got some decent soil there, we're interested in keeping it green all year long, if possible, is there a certain time of the day that's best to water?
Zane: Yes. Definitely, the time and the frequency are two important factors. For a hose dragger, like myself, I think you are best to really focus your efforts on what you said, the curbside appeal. If you had to divvy up your resources and your time, I would focus on that front yard piece. Then from there, the ideal time, in my opinion, would be anytime between the hours of 5:00 AM to 8:00 AM. There is a much wider window than that. I would say anytime from probably 11:00 PM, all the way to 10:00 AM is your true water window, but that's not really realistic for many of us. When you get up in the morning, and you have that cup of coffee, get your hose out and water.
There's a few reasons that that time is ideal. The times that you want to avoid is certainly right in the middle of the day. We're going to see one, a lot of that water will be lost to evaporation just because of the heat. Water has a relatively high what's called specific heat. The specific heat of water, it's pretty unique water, in general. One, it takes a lot of energy to change the temperature of water by one degree. A lot of energy is required to do that, but once the water temperature is increased, it holds that energy. By irrigating in the middle of the day, you actually will see that you can raise the soil temperature somewhat significantly by irrigating. The middle of day is really a no, no.
Then the other time that we want to avoid is in the late afternoon. Several of the turfgrass diseases require a specific amount of what's called leaf wetness period. You think about leaf wetness, when you walk out in your yard, in the late evenings with no shoes on, you can feel the dew is beginning to form on the leaves. That would begin the period of leaf wetness. That's typically going to be in the summer months, somewhere around that 9:30 PM, nine o'clock timeframe.
Irrigating anywhere, probably between that 6:30 PM to 8:30 PM timeframe, what you end up doing is you wet the leaf blades, and there's not enough time for the leaf blades to dry and you end up extending the period of leaf wetness, and several diseases require 10 to 12 hours of continuous leaf wetness. The late evening and the middle of the day would be the times to avoid. Ideally, I like to see people doing it in the morning. There's very little wind during that time and you're able to one, watch the system and move things around. One, that would be the ideal time, Doug, would be early in the morning.
Doug: Then if you do it early in the morning, those blades will have a chance to dry out too, right?
Zane: Correct. One, there's going to be dew on the leaf blades already, so the leaf wetness piece is null at that point. In fact, we actually see that irrigating can knock that dew off of the leaf blade sometimes and actually decrease the leaf wetness period. There are a lot of benefits to irrigating at that timeframe.
Doug: Next question. How often and how much?
Zane: [laughhs] There's the million-dollar question. This is another one that, during the true heat of the summer months, I think you could probably get away with twice a week. You might see a standard recommendation of irrigating three times a week. That will be related to what is the uniformity of your irrigation system and how much did you water and if you can get those things dialed in, you probably could be twice a week. I typically see people are more like three times a week.
How much? This is the great question. In an ideal world, if you had a crystal ball, you would supply the turfgrass plants with just what they need and nothing more. Anything additional is a waste. The way that we can measure that is we have several different methods. We can look at the soil moisture, we can look at what the weather forecast is, and was, so through the process of what's known as evapotranspiration, and we can actually somewhat estimate how much water was used by the turfgrass plants that day.
The standard recommendation is that turfgrass plants will use about an inch of water per week. This is where, for most homeowners, we can, I don't want to lose anybody here, but the reality is, we don't speak about irrigation in home lawns enough in terms of the amount of water. It's all on time because those irrigation timers are all based on time. How many stations and how much time? Even us, moving these hoses around, I put it in 20 minutes in each spot.
The reality is we would love to know how much water through the use of catch cups and we could go down through an irrigation [unintelligible 00:19:38], but the reality is, we don't have that much time, for a lot of people. That is the true way, Doug. If you said how much, it's a loaded question, but the reality is you really would need to know how much water that sprinkler puts out and to actually capture some of that. That can be done relatively easy with just cans and setting them out and irrigating and then going back and looking at how much water was collected and doing some simple math.
Putting out anywhere three-tenths to a half-inch of water each irrigation cycle would be close to ideal. If you're having runoff and things, that's too much. If you have steep slopes, you might have to do, we call it soak cycles, where you water just to the point of where you're about to have runoff and you stop. Maybe the rest of your lawn that's relatively flat, you can run cycles for 20, 30 minutes a piece, but on a steep slope after 10 minutes, you're generating runoff.
That's not good for our business. That might be a situation where you have to run it for 10 minutes, let something else run, come back and run it for another 10.
Doug: Well, I like the idea of putting that catch can there, whether it's a tuna can or whatever it might be. Put that in place, run the sprinkler, and when that thing's filled up to an inch, we know we've got the water. We're assuming we're on a flat. We've given the grass what it needs, right?
Zane: Correct. Doug, the reality is our industry is under scrutiny for water use. Not so much here in our area, but you start to head out west and you hear about people being paid to take turfgrass out of their lawns and, et cetera.
That's a whole nother conversation, but make no mistake about it. Our industry has recognized that water and how we manage water is a huge part for us. The reality is not everybody has all this training to make these really informed decisions. The thing that's coming down the pipeline is just the use of data and technology and smart controllers. The data's out there already and this is getting away from the dragging hose conversation versus people that have actual inground sprinklers, but we see just massive reductions, 50%, 60%, 70% on the regular basis in terms of the water reduction that we're able to make.
In terms of someone dragging hose, how do you really know how much water you put out there? Unless you use these cups, it's a guess. If you're guessing, I always tell people, you can always put more down. You can always add more, but once it's down, you can't take it away. In terms of irrigating, you'd be better off to err on the side of too little because you can always come back the next day and put it down again, but once you start over-irrigating, that ends to a whole other slew of problems.
It creates anaerobic soils. You to get reduced rooting, disease issues, a lot of thatch production. It's an important tool. It seems like it would be simple and unfortunately, I'm somebody who can probably make it over-complicated. It is simple, but at the end of the day, if you don't know how much water you've put out, you are guessing. To take the time to set a cup or two out. If you're doing that, you're far a step ahead of what I see a lot of people do.
Doug: Great stuff, Zane. We're out of time for this week, but you and I are going to keep talking for part two of this podcast where we'll discuss more about having a great lawn. Remember to tune in every Thursday to the Talking Trees Podcast from the Davey Tree Expert Company. I'm your host, Doug Oster reminding you on the Talking Trees Podcast, trees are the answer.
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