 I'm going to talk about shade tolerance and warm season grasses and the reason why I do this is because there's a constant battle in the landscape. People like trees and people like lawns and turf grasses. And the problem is they do not coexist very well. And when there's a competition between a tree and a lawn grass, the tree always wins. There's really no competition there. A tree is 30, 40 plus feet tall. The grass is a couple of inches tall. It's no surprise who wins for light. But I did want to point out a few things, which is all turf grasses. It doesn't matter whether we're talking about a zoysia grass lawn in Birmingham, Kentucky bluegrass lawn in Detroit. It is true that all turf grasses are full sun plants. Think about where you find turf grasses out in nature. It's not a forest understory plant. Grasses come in in the clearings where there's light hitting the ground. They're the first colonizers after, say, a forest fire or some disturbance in the forest. But when the trees get tall enough to shade out the grasses, there they go. It is true that we do have some grasses that can tolerate a little bit of shade better than others do. And that's really what I'm going to spend most of the time talking about. In general, cool-season grasses are less bad in the shade than warm-season grasses. But we are Alabama extension. And so I'm going to make this a very Alabama-centric viewpoint. And we use mostly warm-season grasses in Alabama, which are, in general, the ones that are the worst in the shade, unfortunately. Now, just to hammer home what I was saying before, if you look at a diagram of the dominant biomes in the country, the southeast is really dominated by forests. Yes, we do have some clearings here and there where we had some grasslands. But this is not really grass country, okay? Left to its own device, your lawn would probably end up becoming a forest, and you would lose all the grass out of it. One thing to remember, we don't have too many grasses that we can use for turds that are native to this region. So we end up importing a lot of them, even though the warm-season ones. Now, I have mentioned before warm-season grasses and cool-season grasses. I don't want to go down a rabbit hole too deeply on this, but I do want to mention that there is a basic physiological difference between warm-season grasses, the types of grasses that we're going to grow in Alabama. This is the group of grasses that includes Bermuda grass, Zoysia grass, Centipede grass, St. Augustine grass, Pahaya grass, Seashore pass-pallet, if you guys have heard of those grasses. The cool-season grasses include your typical Yankee grasses, okay? Blue grasses, bent grasses, fescus, and rye grasses. Those are the main groups of cool-season grasses that you'll see used really across most of the country, but not here in the southeast. It's just a little too hot for a little too long in the summertime, and our cool-season grasses can't really take that. And the difference is the way they do photosynthesis, I'm not going to get into the mechanics of photosynthesis and plants, but I will say this, the bottom line is our warm-season grasses, the way they do photosynthesis, takes more energy. And remember, where do plants get their energy from? Sunlight or light, okay? It's a more efficient way of doing photosynthesis when it's hot. It allows the plants to conserve water and therefore be more drought tolerant as well, but it takes more energy. And so therefore, plants that come from generally tropical or subtropical climates, where there tends to be an even amount of sunshine through the year. The sun is at a high angle in the sky most of the year. And it's hot and plants have to worry more about water loss. Those are the environments that favor a C4 plant. A C3 plant is going to be generally favored by a more temperate environment. It takes less energy to make a molecule of glucose using the C3 pathway for photosynthesis. And that's great, means that those plants don't need as much light, but it's not as efficient or as drought tolerant. So in a warm environment, we generally see warm-season grasses. That's great. They're much more drought tolerant. And that's great, but they do need more energy, which means they need more sunlight. Now, how much do they actually need and what happens when they don't get it? We'll get into the how much do they need question here in a minute, but this is a great example of what happens when they don't get the light they need. So this is a lawn that is in heavy shade. You can probably see Magnolia leaves on the ground here. There's Magnolia branches right at the top. There's the picture. There's a big old Magnolia tree and other trees providing a lot of shade in this area. Now, there's green stuff on the ground. And from a distance, you might say, well, that doesn't look so bad. And it may not be so bad depending on what you want to use the lawn for. Now, this happened to be not a private home, but a commercial area where they were doing things like meetings, events, weddings, that sort of thing on the lawn in other places. And so that doesn't help, obviously. But what you find is in the heavy shade there, it's not grass. So you get a close-up and it's mostly Dicondra, which is this little broad leaf with the brownish leaves here. These needle-like leaf plants here. Those aren't actually grasses. That's probably yellow or purple nut sedge, some kind of a sedge. There are some itty-bitty patches of the original zoysia grass that was sodded there peeking through, but not too many. So you've been taken over by the sedges and the Dicondra, the odd patch of some other kind of a weedy grass. And that's what's surviving in the environment much, much better than the grass is. The only way you can fix this is to cut down some trees. So I say it as a joke a lot or at least limb up some trees. So I say it as a joke a lot, but it's actually true. A lot of times, the best tool you can use to increase the health of a lawn is a chainsaw. And the problem is, of course, if you have a beautiful, old magnolia tree shading part of a lawn or you want to have events, you probably don't want to cut that down for a number of different reasons. Aesthetics, the coolness the shade provides. And so then we start talking about, well, what do we have that we can use as an alternative ground cover in really shady areas? And there are actually a lot of things that grow better under heavy shade than turf grasses do. They usually don't have the major desirable characteristics of a turf grass, which is that you can cut it really short and it will take a lot of traffic. Okay, so for example, I mentioned Dicondra. So here is out of that same lawn, another little corner here that gets a lot of shade. And you can see it's almost all Dicondra right here. And the Dicondra is running. It has stones that will spread, but it doesn't have a very deep root system. So it's not very drought tolerant and it's not very tolerant of traffic. So if you have a lot of people walking across the Dicondra lawn, it will rip up. We have Ivy, okay? Ivy does great in the shade compared to a lot of other plants. But you can't mow it down really short and have an event on it. It hides snakes. It climbs up trees and can damage trees and buildings. So there's a lot of cons to something like Ivy as well. We used to use a lot of Asiatic Jasmine on our Auburn University campus. Underneath trees and such, we kind of got away from that. It's not a, it's pretty disease-prone. Doesn't tend to persist as a thick ground cover for us. We've just gone to Pine Straw on the Auburn University campus and mulch in some areas, but mostly Pine Straw where we don't want to keep fighting Mother Nature and keep trying to grow grass in areas where there's not enough light. If you look here in the back of this picture over by the driveway where there's a lot of sun, that's where the nice, thick, healthy Zoysia grass is. So how much light do you actually need? When I first started working at Auburn, and this is probably what most people who work in the landscape industry will tell you, if you try to rank the shade tolerance of warm season grasses, you'll come up with a list that looks like this. And I intentionally used this terminology. I started off talking about the grasses that are worse in the shade and then ones that are not quite as bad and then less bad than that, rather than turning around and telling you, oh, St. Augustine grass is a shade tolerant grass. I mean, it's okay in the shade for a grass, but it doesn't have the same shade tolerance as like an Azalea bush or the English ivy or some of the Mondo grasses, things like that. So I never like to say that such and such a grass loves the shade. That's terrible. No grass loves the shade. You won't find a sod farmer out there deliberately planting trees in the field of St. Augustine grass, because St. Augustine grass loves the shade. It grows great in the full sun, all right? But it's less bad in the shade than most other grasses. So this is our traditional ranking, Bermuda grass, very, very bad in the shade, Seashore Pass Palom, which is something that we see sometimes in Alabama, particularly around sports fields and golf courses, not too much in lawns yet. It's a grass they use a lot more of in Florida and South Texas than they do in Alabama, because it's not very cold tolerant. You can't get it too far away from the coast and expect it to survive the winter. Then we have zoysia grass and centipede grass as a little bit less bad in the shade. And then St. Augustine grass was always the go-to species of warm season grass if you happen to have shade. But there's been some advances in turf grass breeding lately, and there's been some development, especially within the zoysia grass. Newer varieties of zoysia grass tend to be more shade tolerant than older varieties. One way you can measure this is to just use a light meter. So for example, spectrum technologies, they're not the only ones that make these things. It's just the one I happen to have a picture of there, because I have some of these. They make a light meter that you can stick in the ground or use in a greenhouse. It works both places. And if you leave it in the ground for 24 hours or more, it will give you a very rough reading. It's just got four LEDs here that light up. And it'll give you a rough idea of what we call the daily light integral, which is just a measure of the total amount of light energy that's falling on this light meter in a 24-hour period. And the units are moles per square meter per day. It doesn't really matter. But what does matter is the higher the number, the higher the amount of light energy has fallen on that light meter over the past 24 hours. So you can stick these in the ground for 24 hours, pull them out, and get a little bit of an idea whether you have enough light to grow a given grass. So this is some data that's actually kind of old right now, but it's showing the progress we've been making. So Tifway Bermuda grass right here is a very, very common lawn grass, also used very often in the golf courses and sports fields. It's still the standard Bermuda grass in the southeast. And I say still because this stuff was released in 1960. Okay, here we are, 2022. This is still the vast majority of all the hybrid Bermuda grass in the state of Alabama. And you can see here that it's going to require somewhere between in the spring and fall a little bit less because it's not quite as hot, not growing as fast. Summertime, 22 moles of light energy per square meter per day, that's a lot. We look at some of the newer varieties of Bermuda grass and we're seeing these numbers coming down a little bit. So less bad in the shade. Then when you get to Centipede grass, we see numbers here of 14 and 13. That's a lot less light. So this is going to be in most locations in Alabama to get a DOI of 20. You need to have about eight hours of sunlight total, direct sun on a given location. This is translating more to about six hours or so. And then we get down into the St. Augustine grass, you know, 11.6, 11.8. That's roughly more like four or five hours of direct sun. And some of the newer varieties that have come on the market, this is from 2012, there's some newer ones still that are down in this 11 to 12 range of zoys just as much shade tolerance as St. Augustine grasses. And so that's given us some more options of grasses we can use if you're in a position to, you know, maybe you're planting a new area or if you're in a position to switch your grass. You may want to look at the newer zoysia grasses rather than the old standbys like Meyer and Emerald. This is a picture that I just took in March of this year. It was before the trees leafed out. But it's showing you what happens when you have, in this case, a legacy variety of zoysia grass, Emerald zoysia grass planted in a subdivision. This is just a street in a subdivision here in Auburn. And you can see on the right side there, I was driving through this area. It was about 130 local time in March. So that's just after solar noon when we're on daylight savings time. And you can see where the shade problem is just by the outline of the tree branches. Of course, now that the trees have leaves, I need to go back out there and take a picture of the actual shade. But you can see where the problem is going to be. And you can tell how much thinner the grass is here than it is on the extreme right where it's getting a lot of sun or in little pockets where it's getting more sun. This is an area where you should think about, if this grass dies, which it probably will, either coming in, you might have enough light there. I doubt it to try one of the newer varieties of zoysia or you may just want a punt and bring on the pine straw and just have this area be pine straw, maybe put some more zoysia in there and just be done with grass. I talked to the HOA president of this subdivision and it's about a 15 to 20 year old subdivision that looks about right for these trees. And when they first planted those trees, first built the subdivision, they were not big enough to be causing enough of a shade problem to do this to the grass, but now they are. That happens so much. You hit that 15 to 20 year mark on a new house, new subdivision, new commercial development when the landscaping starts to mature for you start to get bigger. All of a sudden, all that area that could progress 10, 15 years ago, there's too much shade there. And you have to start thinking about other things. So now when I think about the relative shade tarts and warm season grasses, Bermuda grasses are still the worst and they always will be the worst as a group. However, I think sometime in the near future, we'll probably have some shade tolerant Bermudas that will overlap with the C-sharpas palums. Centipede and zoysia grass, in my mind, I call these legacy varieties, but the old varieties. So things that came out before about 2000, the zoysia grasses that came out before about 2000, I still lump in with centipede and then the newer zoysia grasses, they're pretty much right in there with the St. Augustine grasses in terms of their relative shade tarts. But it is still definitely possible, as that picture shows, I'll throw it up there again, to have areas where there's just not enough light to grow any turf grass and that's where you have to get creative. So this is just a recap of the numbers there. It is possible if you have the money to do crazy stuff. So this is Hard Rock Stadium and these are two of our former turf grass student interns who were interning there a couple of years ago. They have this roof over the seating area. That stadium didn't always used to have it. It's a Bermuda grass field and when they renovated the stadium and put in that roof, they also put in at the ground level, field level on the stadium wall, these large power supplies for a dedicated circuit for putting grow lights on and they actually have portable, they weren't actually, these are not actually plugging into the grow lights here and then the grow lights out when I was visiting, but they've got these racks of just LED grow lights that they can move around and they have outlets for them all around the outside of the field so they can move them all around the field wherever they need a little bit of extra light. So if you're made of money, there are ways to compensate for shade, but most of us are not an NFL team and so we have to think about designing the landscape so that we only put the grass where there's enough light for the grass to grow, right? So here's a nice example of that. We all see this to a certain degree where right underneath the cluster of trees, we're going to have shade trauma shrubs, azaleas or whatever, we're going to have a different ground cover than turf grass in the shady areas and again as the trees grow, this might have to creep out some as the area that actually is getting enough light to grow good turf grass shrinks and that's okay, even though I'm a turf grass guy, I do spend a lot of time trying to convince people not to grow turf grass in areas where it's not going to do well and part of that is just because it feels so good when you stop beating your head against the wall. Here's a good example. This tree is not too far actually from my office. This is Comer Hall, the main administration building in the College of Ag on campus here at Auburn and on this hillside right underneath this big old oak tree, that's not a turf grass. That's say a Mondo grass which is not actually a turf grass and it's just much better right underneath that tree. Now there are some areas of the Comer lawn that still get a little bit of shade from that tree, but not enough during the day to completely kill grass and so we do have a nice amount of zoysia grass on the front lawn of the building there, but right underneath that tree, underneath the drip line, why bother? I mean, you have other things that can look good that aren't turf grasses, so use those. And then quick, I'm just going to wrap up with this reminder. It isn't always shade with trees either, okay? This is actually my front yard and I have these two pine trees that sit in my front yard and they're really, they're very tall and they don't have any branches for about the first 15 or 20 feet. So this area of my lawn actually gets enough light mostly for me to grass. We'll ignore this little patch of another grass in here and focus on this area right here which is drying out from competition with the feeder roots of these trees for water. That's all that's happening here. So you look as you get farther away from the trees, the grass gets greener and as you get closer to the trees within about a, maybe it's about a 15 foot radius from the trees, this grass is just getting really crispy and drying out. So grass does not just lose the competition for light with trees, it often loses, almost always loses the competition for water too. And so in Alabama, you know, if it doesn't rain for a week or so during the summertime, my grass underneath my trees is going to start to dry out whereas the grass that's closer to the street you're farther away from those trees, doesn't dry out as fast. And then so that's another thing that happens in competition. Okay, so that's about it. There's my contact information up there again and I will go ahead and turn the meeting back over to Dr. A and stop sharing my screen now. Thanks a lot for your attention.