University Place  Dog Soldat Dealing with Drought: Repair and Prevention  February 9, 2013 UP832   cc >> Okay. Well, good morning. My name is Doug Soldat. I'm a UW Extension specialist in turf grass and urban soils, and I also run the Turf and Grounds Management Program in the Department of Soil Science in the College of Ag and Life Sciences. Most of our students, we have a small program, maybe 15 or so students, and most of them go on to become golf course superintendents, lawn care operators, sales and distribution, sports field managers, things like that. So, this year was incredibly challenging, and I learned a lot about grass and dead grass and things like that. And I'm sure that's what's uniting all of us here in this room is that we have a lot of dead grass. So what we're going to do today is we're going to go through some of the basics behind what happened, what caused it, why did some grass live, why did some grass die. We'll show you a lot of pictures, we'll tell some stories, and then at the end we'll talk about grass selection and moving forward and how to repair the damage that you have and hopefully how to prevent or minimize that damage and death from occurring again. So, evapotranspiration is kind of the big, long scientific word that we use to describe water loss from a system. 

So, rainfall precipitation comes down, and then that leaves the system either by evaporating off the soil surface or moving through the plant leaves. We call that transpiration. And because we can't, when we measure these things, we can't really differentiate between evaporation or transpiration, so we just mash them together and call it evapotranspiration, or ET. So that's what I'm going to show you now. Well, ET happens through the stomata. So this is a stomate which is a little pore in the plants leaves. This is a really close picture of a leaf, and the leaf has these holes in it, basically to get carbon dioxide in to the plant. And then it uses that carbon dioxide to make sugar, but one of the consequences of those holes, or having to get carbon dioxide into the plant, is that that's where water gets lost through. So when those holes open up, water leaves the plant. So this is a graph of the amount of rainfall versus the amount of evapotranspiration in Madison, Wisconsin, last year. 

So, you can see that part, the red line is the evapotranspiration. It's kind of always a low, relatively constant amount. Maybe a quarter to a third of an inch per day. And the rain is more sporadic. You can see those peaks. Sometimes we can get big rain events; sometimes there's not rain. You see that really long stretch, that really long period is about six-seven weeks with almost no rain at all and pretty high evapotranspiration. So that big, blue arrow is pointing to that period which started in, basically, June and lasted until mid-July. And over that period, we had 11.2 inches of ET. So that was the amount of water that was lost from the soil, and only .2 inches was replaced. 

So that's a huge deficit. So that's just like a bank account. The precipitation coming in is the money going into the bank; the evapotranspiration is what's going out. So you see there's a really big deficit there. And that's, basically, what killed your lawn. But the second part of this graph is what happened, it rained in July. You can see that big spike. Right after our blue arrow we get some rain in late July through August, but what I told you and if you listen to anybody on the Internet or the news about when to repair your lawn, we said August 15th to September 15th is the best time to reseed because this is after the summer stress period. But guess what? That was another drought. We had another huge period of dry weather when a lot of people were trying to repair the damage from the first drought. 

So there in that second period in September we had six and a half inches of ET with only 1.4 inches of rainfall. So when you're trying to grow new grass, having adequate water is really, really important, but Mother Nature wasn't helping out much, which is pretty unusual. So those two periods, the drought that killed a lot of the grass and then the second one which hampered a lot of recovery efforts, which means next year we're going to have to try it again and see if we can get some more help. Okay, so grass is a really, I'm really biased because I study grass for a living, but it's one of the coolest plants around because it's growing point, which we call the crown, is at or below the soil surface. That's like the bud. Everything comes from the crown. So you think of oak trees or any other plant you can imagine, and now think about mowing the tops of them off and how well that would work out. It wouldn't work out at all because the other plants have their buds, their growing points, at the tips. So grasses are unique because they have that growing point at or below the soil surface in this thing we call the crown. And the crown looks like that. 

It's like an onion. You never see it because it's always in the middle of all the leaves. So you can't really see this thing other than in a picture, but that's where everything that comes off the plant originates from that crown. So the roots come off the bottom of the crown, the shoots come off of the top, and then you get some other cool structures coming off the side. And so when that thing is alive, the plant's alive. We don't care about the top. We don't care about the leaves. The roots grow and die back. If that crown is alive, the plant is alive. So when that crown dies, that's when the grass dies. 

I said some weird things come off the side. That's what we're going to talk about now. We call that the growth habit of the grass. So, one of the things that can come off the side of that crown is called the tiller, and a tiller is essentially a new grass plant with its own crown. So it just divides, essentially. And grass, your lawn, we think of it as being a perennial. It's really not a perennial. Each individual plant is probably more like an annual. So that crown, average plant, like this with one crown, probably doesn't live much longer than a year. But because it divides off of itself and produces another plant which produces another plant which produces another, it's kind of constantly regenerating. 

So your lawn, even though it looks the same year to year, every time you look at it, it's a whole collection of new plants. So tillering is what all grasses do. Every grass has the ability to split off of itself. And tall fescue and rye grass are called bunch type which means that's the only thing they can do. That's the only way that they can spread non-sexually is by what we call tillering. So if you look at that picture there, you see there's kind of a clump. And there's, I don't know, maybe seven or eight different plants that are coming out of that clump. Those are all tillers from an original mother plant. So the problem with tall fescue and rye grass, which only divide by this, is that you get clumps. It doesn't have the ability to cover and spread in large, cover large areas. 

Now, this is five tillers. The leaves aren't individual plants, but those white stems, those are individual tillers. So you can see maybe a little bit more clearly what that looks like. Now, the rhizomatous growth habit, this is much better because now, coming off that till, we can have tillers coming off that crown, but we can also have rhizomes, and rhizomes are underground stems. So they burrow through the ground, and they can go large distances. Four inches or so. And then they can form new plants. So these spread and fill in dead spots a lot better than plants that just tiller. So our main grass that have rhizomes are Kentucky bluegrass and creeping red fescue. So we like these grasses for their ability to fill in damaged areas. 

Now, these rhizomes are more than just stems. They actually are storage organs with their own buds on them. So, this is a picture I took of some Kentucky bluegrass that was totally dormant during the drought. You can see I've labeled the various parts on there. You've got the leaf, the leaf blade, the leaf shoot, and the roots. So the crown is right at the middle of that, and you can see what I mean about you can't really just look at a crown to see if it's still alive. But you have that really big rhizome that's coming off the end, and every centimeter or quarter inch or so you have little nodes, and each one of those nodes has the ability to start a new plant. So, even if that crown dies, that original crown in this plant, let's say it's dead, that rhizome may still be alive. And when the soil moisture conditions return to optimum conditions, that Kentucky bluegrass plant can regenerate itself from those nodes on the rhizome. So that's one thing we really like about Kentucky bluegrass and creeping red fescue. 

Now, creeping red fescue's rhizomes are not as vigorous as Kentucky bluegrass. So Kentucky bluegrass is going to be a more aggressive spreader than creeping red fescue. Now, this is the best one. [LAUGHTER] This is the reason you all have quack grass, and you can never get rid of it. Does anybody know what the recommendation for getting rid of quack grass is? >> Move. >> Sell your house. [LAUGHTER] Yep. In the winter, preferably, when there's lots of snow. The other one, I heard it out there, Roundup. Probably not just once but again and again and again because those storage organs, those super strong, thick rhizomes have the ability to regenerate even after you killed the original crowns with Roundup. 

So, quack grass, really good rhizomes. So now my question to this group, is this grass dead? >> No. >> Okay. Why not? >> It's dormant. >> It's dormant. Does anybody have dead grass that looked like that at one point? Yeah. Maybe the answer is we don't know. Probably not. That's what I did. The newspaper call a lot and say, is the grass dead? After three weeks of the drought, I said, no, it's not dead, it'll come back. 

And then four weeks, mm. And then at six weeks I was really nervous, like yeah there's probably a lot of dead grass out there. So the point of this question is, is the grass dead? Yeah. There's a lot of dead plants in that picture. Even though it's dormant. But is the lawn dead? That's the better question because remember, the ability to regenerate is really what's key here. This is Kentucky bluegrass. This recovered really, really strongly. This is on the University of Wisconsin campus, and this looked like this for four or five weeks, but because it had rhizomes and Kentucky bluegrass can survive this for an extended period, most of it came back. This is my house. 

This is in July after the rains came, late July. Is that grass dead? Most of it. Yeah, a lot of the green stuff are weeds. How about that stuff by my mailbox? What's that? >> Crabgrass. >> Crabgrass. Yeah, crabgrass. That's like the rockiest part. It's horrible. I try to kill it. I weed-whack it down, and it just comes back. 

So what's going on there? >> Your -- are still alive. >> Well, actually, it has to do with some biochemistry, and you probably did not expect to see this Saturday morning. [LAUGHTER] I tricked you. It's going to be a biochemistry lesson. [LAUGHTER] I just wanted to tell a little story about, basically, biochemistry, but I think it's really interesting. Raise your hand if you know what RuBisCo is. See. RuBisCo is like the most abundant and the most important protein in the history of the world. So that's what I'm trying to convince you that you should pay attention here. So this is, I'll say that again, the most abundant and most important protein in the history of the world. 

It's an enzyme and what RuBisCo does is takes carbon dioxide from the air and it fixes it. It basically makes it into a sugar. So this is why we have life on Earth. RuBisCo, a very specific protein that's an enzyme, grabs carbon dioxide and makes it into a sugar. That's a huge function. It's unbelievable. The problem is, RuBisCo's not very good at its job. So maybe you know somebody like this at work. They sign a paycheck, they're very important to the company, but, okay. So this is RuBisCo. 

It's hugely important, but it has shortcomings. One of its shortcomings is it gets confused. It doesn't know, it can't tell the difference between carbon dioxide and oxygen sometimes. See, I lost them. [LAUGHTER] See you later. So, I promise, it won't all be like this. But anyway, so it grabs, it takes oxygen, and when it grabs oxygen instead of carbon dioxide, it causes the plant all kinds of problems. So if it only grabbed carbon dioxide, there would be no issue. But this is how the vast majority of plants deal with carbon. Crabgrass does this. 

Okay? So crabgrass has a different type of pathway, and what crabgrass does is basically fixes that inefficiency. So it has a different enzyme that grabs the carbon dioxide and it moves it to that bundle sheath cell, that's the big green one. And that bundle sheath cell has no oxygen in it. So it basically takes RuBisCo and moves it into an area where it can't make a mistake. So when temperatures get hot, RuBisCo actually gets worse and worse at figuring out the difference between carbon dioxide and oxygen. So, in hot temperatures, that's when our normal grasses start to decline. Crabgrass, which has this special pathway, RuBisCo can't make a mistake and it can tolerate those high temperatures. So it's actually like that PEP carboxylase, that's the enzyme that's, you can think of it like a shuttle bus. It grabs the carbon dioxide now and it moves it down into the green cell and drops that carbon dioxide off. So it's like get on this bus, we're going to take you to the site where RuBisCo's going to do its job. 

So it's a pretty cool biochemical fix. And that's, of course, why it looks so good here. Yeah, question. >> That's a special pathway there. Is there a particularly good way to get at that uniquely? >> So, the question is, if that's a special pathway, is there a special way to get at that uniquely? >> To get rid of the crabgrass. >> I don't think so. That's a good question. I could hire you and maybe you could work on that. [LAUGHTER] I don't think so. The other thing about this, though, is that people are trying to engineer this pathway into other plants, like especially rice is the world's number one food crop, and rice is a C3 plant but it's grown in a lot of hot regions. 

We could increase the productivity of rice if it had this pathway. So maybe 50 years from now we might have Kentucky bluegrasses that have this little trick. But right now, this is why crabgrass has the advantage. And, basically, the bottom is a grass like crabgrass, grows during the year really well in the summer when it's hot. Kentucky bluegrass is kind of like the top one. Okay, back to my house. This is my yard when I moved in in 2006, and this is the other problem with the drought is the way that urban soils are treated. So, this is just absolutely unacceptable. How can you grow a plant in something like that. And I didn't do a Google search for the most egregious soil on Earth. 

This is just my house. So if this is just what my house looks like, imagine what every other house in Madison looks like. This is the backyard in spring. So this was November. This was the spring. We have that totally compacted subsoil, and now we have about two inches of black dirt brought out on top, and then we expect to have success growing anything in that. So the way I like to talk about this is, let's say my wife wants to put a garden in the backyard, what should I do? Raised bed. That's what everybody says. Exactly. [LAUGHTER] You cannot grow plants, you cannot grow healthy plants in that. 

And I think a lot of people have a bias against lawns. It's a monoculture and all this stuff, but this is the reason we have a lot of pest problems is because we don't treat the soil like we would for any other type of plant. So it's like plant discrimination. You would never expect to grow your food crops in this, but this is kind of the normal situation for lawns. So you wonder why your lawn dies or you have a lot of weeds. It's because of this, not necessarily because of the grass itself. >> Manure helps soil too. >> Yeah, we'll talk about that in a second for sure. >> [INAUDIBLE] >> Yeah, we can go on all day about this. So this is another picture about soil. 

This is our research station out on the west side of Madison, and you can see those tracks, those brown tracks where the maintenance vehicles drive, that starts browning out first because the soil is compacted. So it's the same grass, everything's the same except when you compact that soil or when you have a poor quality soil your plant runs out of water. It doesn't have access to enough water. So you start to see the browning there first. So the question is, how long can this grass survive? Well, it matter what the soil type is. It matters what condition the soil is in. If you have healthy, like most of the pictures there, healthy, green grass, deep soils, you can live a lot longer. That grass can survive much longer than if it has compacted or ruined by construction activity. So, for minimizing the effects of drought, you need deep, uncompacted soils. Core cultivate, which is really kind of a temporary Band-Aid solution. 

That's when we're pulling those cores out of the lawn. It's only really getting the top two, maybe three inches. So the deep compaction is really a bigger problem. But core cultivating will help a little bit. And adding compost, I think twice a year, quarter inch of compost, which you'll come to that amount normally because it's about the maximum amount you can tolerate. It works it way into the canopy. About a quarter inch in the spring, a quarter inch in the fall, really improves that soil over the long term. So this is a research study we did with compost on a whole bunch of different park areas out in New York. So, one site in Buffalo and the other in Rochester, and you can see we're adding different amounts of dairy or poultry compost at different rates per year. And this is a water infiltration rate after three years of making those applications. 

So this is how many inches of water can soak in per hour. So the control, on the bottom there that says five and three, that's when we didn't add compost. And then the fertilizer one is not compost but we did fertilize it. So you can see we increase our infiltration rate by two or three times by adding that compost every year. And if you're increasing water infiltration, you are improving the quality of that soil. So adding compost, extremely laborious, there's not a real easy way to do it, that's the main reason people don't, but it makes a huge difference for soil quality. The other thing I'm going to talk about is grass selection. This is usually what we get fixated on. This is a top question: my grass died, what should I plant? What I would like people to say is: my grass died, I have the opportunity to amend my soil, how should I do that? Grass selection, I think, is secondary to improving the soil. But anyway, we'll talk about it. 

So this is common Kentucky bluegrass. And the turf grass community talks about grasses as common, and that means they're related to the forage varieties. So all the grasses that we have were used for forage. Then we have turf grass breeders coming in the '60s through now, and they select these forage grasses to behave more like what we want our lawn to do. So if you're interested in forage, you want lots of quick growth. If you're interested in lawns, you don't want to mow it. You want a dark green color, all this stuff. So, that's what the breeders have basically done. So this is like a forage Kentucky bluegrass. No herbicides. 

So we established it. We kept the weeds out on year one, and this is three years after that, and all we did for those three years was mow it and put down fertilizer. And this is either no fertilizer, two applications per year, or four fertilizer applications per year. Okay? And that's what the grass looks like. So this one's not going to win any awards. It kind of looks the same. Doesn't look very good at four. Doesn't look very good at zero. So this might be the reason people say don't use a common Kentucky bluegrass. They'll say, use a premium Kentucky bluegrass. 

[LAUGHTER] Okay? Because if you fertilize you premium Kentucky bluegrass, it looks premium, but we know most of the people don't fertilize four times a year. Two times of year is actually sort of rare. How many people fertilize twice a year in this room? How many fertilize more? How many fertilize less? So there's more people fertilizing less than two pounds per year than more, and probably a half of the room is fertilizing twice a year. And this is the group that's interested to get up at 8:00 in the morning and come over to the Expo Center and listen to RuBisCo. [LAUGHTER] So, anyway, the premium Kentucky bluegrass, this is what the sod growers grow, the majority of them. Now, we're working with sod growers, they know this problem, they don't want to sell you grass that evaporates if you don't fertilize it. Essentially, it goes away. So the sod growers are starting to go back to some of the older varieties that are more aggressive and more competitive with weeds under low maintenance situations. But the general statement is most sods are going to be premium Kentucky bluegrass. Perennial rye grass, not a good option. 

Same thing, if you don't fertilize it, it tends to go away. Now, this is a bunch type grass. So the Kentucky bluegrass at four fertilizer applications looks pretty good because if it dies, it can creep back in, but the perennial rye grass doesn't. It doesn't really like our winters very well. So you can see, even at four fertilizer applications per year, there's not a whole lot of perennial rye grass left, and that's related to its lack of rhizomes. Oh, pretty, right? Fine fescue. This is a chewings fine fescue. Very low maintenance grass. We've been recommending the heck out of this for the last five years, and we had to eat a little crow this year with fine fescue, which I'll show you in a minute, but this is why we like fine fescue. Under very low fertility and maintenance, it does really well. 

Its drawbacks are traffic. It doesn't like a lot of traffic. It doesn't like compacted soils. It doesn't like wet soils. And when I say doesn't like, it means it won't grow there. So if you have compaction, wet, high traffic, forget about fine fescue, but if you don't, it's an outstanding grass. Sun or shade in most situations. Tall fescue is a newer one. This is what I have in my yard. It looks very good under low fertility. 

So, you can see there's a lighter green color, but the weed population is really, really low with tall fescue. So, fine fescue, I've been recommending that a lot. Tall fescue doesn't like ice. If you have ice accumulation, it does fine in snow, it does fine in cold, but the second you have low-lying ice areas, tall fescue goes away. So, if you're on a slope, it's a good option. If you're in a low-lying area, it's not. So this is a different study now. With these grasses, all we did was put the seed down. So we raked up the soil, put the seed down, and walked away. There was never any irrigation. 

No fertilizer. No chemicals of any type. Okay? We mowed it once a month. That's why it looks scraggly. So we didn't even mow it properly. But look at the chewings fine fescue. It looks really, really good. Hard fescue, okay for the circumstances. So those are both types of fine fescue. There's hard fescue next to a Kentucky bluegrass. 

But that's what we planted. There's really no Kentucky bluegrass there. So these grasses have the ability, the fine fescues, to survive under extremely low maintenance where Kentucky bluegrass just doesn't. It takes 21 days for Kentucky bluegrass to germinate. By that 21 days, the plot's already covered in weeds. So here's the same study. Chewings fescue versus tall fescue. So you can see why we've been recommending these grasses for low maintenance situations, and both for drought, they both have the reputation of being outstanding in drought conditions. And here's the evidence of that. This is from one of the more recent turf grass textbooks that lists fine fescues as very good in overall resistance. 

Kentucky bluegrass is good. Tall fescue is very good. So those are our two, fine fescue, tall fescue, good at low maintenance, good in drought, but that's not the whole story. This is the real story. This is what we learned this year. Fine fescue died more than any other grass in the state. Far and away. Okay? It didn't matter that the textbook said it was very good. It was not very good. And I think the reason for this, and part of the reason I started off with the crown stuff, is when the crown gets elevated, when it gets up into the air, it doesn't have a chance. 

Part of the reason that crown can stay hydrated if it's below the surface of the soil. But chewings fine fescue, especially, likes to get puffy and grow up. Kind of get soft. You know what I'm talking about? A little thatch. And I think when you get that condition, when that crown get elevated above the soil surface, fine fescue doesn't survive very long at all. So I think it could be a very good grass if you keep that crown down. But unless you're a professional turf grass manager, that might not be the easiest thing in the world. I had fine fescue in a strip in my yard. It all died. This is my neighbor's house. 

They had a beautiful, probably a 50/50 mix of Kentucky bluegrass and fine fescue. This is all dead. Everything that's brown there is all dead. Now, this came back really well. This is another point I wanted to talk about is the stuff that's green there is Kentucky bluegrass. And if you have a Kentucky bluegrass plant, every six, seven, eight inches, it has the ability to completely fill in. This picture was a week or two after the rains came back, but by late fall, I wish I had a picture, but their lawn actually looks pretty decent because the Kentucky bluegrass filled in those gaps where the fine fescue died. But fine fescue did really, really poorly this year. So we're studying this at our west side research station. And this is a rain out shelter we call it. 

Didn't really need it this year, but basically moves on railroad tracks out over the grass area to keep rain off so we can actually study different grass varieties. It's really hard to do that in Wisconsin where it rains so frequently, usually. So we had this rain out shelter and we evaluated drought for about six weeks in the summer. This is a picture early on in the study. You can see quite a good deal after the drought was imposed. And you can see there's some pretty big differences in green color there. So I'm going to share with you some of the pictures and some of the grass varieties that we studied. Excuse me. Okay, so we've talked about creeping red fescue being a good lawn choice from the fact that it has rhizomes, but now we know that it might not be the best choice because of the fact that the crown get elevated and can die. So this is what all the grasses  looked like before the drought. 

So we have this big stainless steel box with a camera in it so the light conditions are controlled. So everything's kind of an equal comparison. So the two types of creeping red fescue that you're looking at on the left side. In the middle is probably one of the most drought resistant varieties of Kentucky bluegrass that we have. And on the right are two different varieties of tall fescue. So these are the three grasses you should be thinking about for reseeding. Kentucky bluegrass, tall fescue, creeping red fescue. This is after four weeks. Now, the soil that we're doing this on is a healthy soil. Your grass didn't look like this after four weeks of drought, but if you had a deep, healthy agricultural type soil that hadn't been compacted, it might look like this. 

So when you hear on the news or the radio that grasses can live four to six weeks with no rain, that's absolutely true if the soil is optimum. But in most of the people in this room, and I'm included in that, our soils aren't optimum. So that window is a lot smaller. So, here's after four weeks. We've got a lot of green color in a lot of those grasses, and even look at that tall fescue in the bottom right. Looks like no problem. It's the tall fescue's really deep, thick roots that has access to more water. Now, this is after five weeks. It's a big change there. Four weeks. 

Five weeks. Now five weeks everything kind of falls off the map except for that bottom tall fescue. This grass gives you another week of green color, but you can see it's variety dependent. That's speedway tall fescue didn't extend that green color at all. Actually, the Kentucky bluegrass looks pretty good, I think. You can see the creeping fescues really browned out quickly. They went from green to almost that whitish color within one week. Okay, so now six weeks of drought and now everything kind of looks the same. We've got a lot of brown hues in there. This is one week after watering. 

Whoa. Wow. So when we say, a lot of the questions we get asked during a drought is, is my grass alive? And we say we don't know because there's not a good way to check. They say, how can we know? Wait two weeks after it rains. Nobody likes that answer but that's basically it. So we water this, some grasses green up right away, and, in fact, the Kentucky bluegrass did almost instantly. That tall fescue on the bottom right grew out, but what about the other ones. Are those grasses dead yet? We really don't know. We need to give the grass another week of growth to see if something comes off the crown or a rhizome or something like that. So this is three weeks after watering. 

And now you can see the true story. The tall fescues lived, the Kentucky bluegrass looks good, but we had some death on those fine fescues. Okay? So, for drought, I like this particular Kentucky bluegrass for sure, and tall fescues do pretty well. But the fine fescues, I think, have been over-sold as being drought tolerant. They tend to have a lot of, especially the boreal creeping red fescue, had a lot of dead areas after six weeks. So, we continue to search for new species, new genes, like we talked about with the C4 pathway, maybe engineering that into a lawn grass would be great. This is a study that's being done at Rutgers where they went out to Yellowstone National Park and they found a grass that could live when the soil temperatures were 120 degrees. So they're taking that back, and they're studying it. None of this is really commercially available or anything, but maybe you can sleep easy at night knowing that these are issues people are working intensively on. Okay, so now we're going to talk about management for kind of the last section of the talk here. 

So what's going on in this picture? This is from Milwaukee Country Club. This is a golf course. Anybody got any guesses? >> [INAUDIBLE] >> What's that? >> Two different types of grass. >> Two different types of grass. That's a great guess, but it's not right. [LAUGHTER] Shade. With square trees? [LAUGHTER] >> [INAUDIBLE] >> Okay, could be the topography. All wrong so far. >> [INAUDIBLE] >> Huh? >> Compaction. >> Could be compaction. 

No. Okay, I'll tell you. You'll never get it. [LAUGHTER] So they trenched in some wires. A trench is like a huge chainsaw. This is root pruning. This is showing the effects of root competition. Not shade, not anything else, but if you cut off those roots, then there's not competition with water for that grass. So this is basically just cutting off the tree roots, and you can see how different that grass looks just from eliminating the competition between the trees. So a lot of times we talk about you can't grow grass under the trees because of the shade, and this kind of shows shade might have something to do with it but probably water competition is the main thing. 

It's kind of a fun thing to talk about. So how much to irrigate? If you want to keep your grass green, you're going to have to replace the evapotranspiration on a weekly basis. That's almost about an inch of water per week, and that's to keep it green. But we don't really have to keep it green all the time. Sometimes you want to, if that's your function, but to keep the crown alive, that's when the grass turns brown but it's still probably alive. We know you need probably about a quarter inch of water every one to two weeks. So we don't have the number really pinpointed, it matters on a lot of factors, but just a very light amount every seven to 14 days will keep those crowns hydrated. If you don't do that, you're just kind of gambling about the soil type and a bunch of other factors. But to keep the grass green, you're going to need about an inch of water. That's one of those old tuna cans, you put that out, figure out how long it takes to fill that up, and that's how much you should water to get an inch. 

You can do the same thing to figure out how long it will take for a quarter inch. Question. >> Is that applicable to compacted soil? >> Is that applicable to compacted soil? That's one of the factors that make this not perfect science. So, the poor quality your soil is, the more water you'd need. That's one of the reasons I really like to focus on soil improvement, adding compost, tilling things up. This is something I see a lot. People like to mow when you shouldn't mow. So this is a lawn that's wilting. It's in the first stages of drought stress, and you go off with a mower and just exacerbate that stress by creating wounds. So this is what that lawn looked like the next week. 

So creating that traffic stress has a huge impact on the survivability. Now, this isn't dead. Those are dead leaves. It's going to take two weeks for those dead leaves to go away and new leaves to come off the crown, but that's not a very nice situation for two weeks. We see a lot of this. We saw this this summer. I think this might even be from near our research station. When you drive on grass and put any type of stress on it when it's wilted, you kill the leaves and you have to wait the two or three weeks for that new plant to come off the crown. This is where my son played T-ball this summer. Is that coming back? No. 

So, this will come back, that won't. So the traffic, you can kill the leaves, that's one thing. When you beat it to this, you're killing the crowns. Mowing height matters. So we talked about access to water, compacted soils have less access to water. The shorter you mow, the shallower your root systems are. So we like to recommend at least a three-inch mowing height. That's going to give you the most access to water. So, I can't talk about all the details of renovating lawn. I'm just going to hit some high points here. 

This is the publication on The Learning Store. It is about eight or nine pages. It's really, really thorough. It talks about seeding versus sodding, grass selection, nine steps to establishment, it sounds like a lot of work but it's not really, lawn renovation. So it talks about partial renovations or complete renovations. So, like I said, download this from The Learning Store to really get into the nitty gritty. But this, again, this is in the outfield where my son plays T-ball. What do you think about this? First of all, is it dead in the middle? >> Yes. >> Yes, because you can see the other grass is green. Will it come back? >> No. 

>> Some of it will. Maybe the edges, it will get smaller and shrink, but this is too big for the Kentucky bluegrass rhizomes to cover. Why did it die in that particular shape? >> [INAUDIBLE] >> You're all right. We don't really know. [LAUGHTER] What it probably is, is a soil issue. This is probably a soil issue. There's something different about this soil than the soil around it. Okay? So what do you do? The problem is the springtime is a really bad time to establish new grass because weeds are growing, and when you establish new grass, you have to prepare the soil which also prepares it for the weeds. So this is a slit seeder. This one is called bluebird. 

You can see it has these knives on the bottom that spin. It creates slits in the soil, and it also has a hopper that drops seed down into those slits. This is probably the best way to go about kind of a minimal disturbance for spring seeding. If we went in and tilled everything up, you're going to have a lot of weeds that are going to also be competing, but if we create these little slits and drop seed in, only that seed that got right in that slit can grow. So it think this is a really good option for smaller areas. You can rent these. They're pretty easy to operate. Commercial grade is going to look a little more like this but same concept. It's got these knives on the bottom and the hopper seed, shoots the seed down into those holes. That's not fun to use. 

It's bulky. It's hard to load in the truck. So if you're a homeowner, smaller area, this is what you want to do. Question. >> Would it be silly to immediately then top it with a quarter inch of compost that you're recommending earlier, or would that just help weeds? >> No, it wouldn't be silly at all. If the compost is a good, high quality source with no weeds, I think that's good practice. It will keep some of the water in the soil. >> Right after that slit seed? >> Sure. Yep. You could do it before too. 

>> Okay. >> How about this guy? How's he doing? [LAUGHTER] It's a lot of work. So there's two things about this picture. Number one, he did it wrong. He should have sprayed a selective, like a Roundup, and waited two weeks for that grass to be totally mushy, and this would have been a lot less work. But the thing is, everybody kind of laughs at this when we show it, but this is the way to really make a difference in your soil. I said soil is the most important thing, and it's probably, the reason the grass died in that area and not others is probably because of the soil. So there's two options you have. You can put new seed, and maybe it will die because it's a poor soil, or you can fix the soil. And I like the fix the soil approach because that's the root cause. 

You can pick different grasses and all that stuff, but the soil is probably the root cause. So we laugh and say this is a lot of work, this is also probably the best solution. But, again, you don't want to just jump right in without killing all the vegetation first. Questions. Sure. >> A lot of that black dirt you get has a lot of sand in it. >> Okay. Yeah, topsoil quality varies, and that's another issue we could spend... >> Do you have any suggestions? >> Any suggestions? What's that? >> Sand is good. >> Sand can be good. 

The clay content is really probably the worst thing you can have. >> I'm all sand. >> You're all sand, compost. Organic matter is going to be the best option. >> Question: when you're slit seeding, should you pull out all the dead stuff first before you slit seed? [INAUDIBLE] >> What's that? >> I said it's an argument. >> It's an argument with your husband. What's your side of the story? [LAUGHTER] >> Just slit seed right through it. >> I'm with you. So, she said just slit seed right through it. So, the problem with dethatching and removing dead material is you're basically preparing the soil for more weeds. 

That's a reason I like to take a minimal approach, also I'm lazy, but a minimal approach to those things because if you do remove all that material, you're just creating spots that weeds can come in. >> So all that work that my husband goes through every year, dethatch. [INAUDIBLE] And every year he gets it in his head to go out there and dethatch, invest in a dethatcher because the neighbor did it. >> Is that your husband? >> No. [LAUGHTER] He's at home. >> He's at home. Okay, so I can say whatever I want. >> [INAUDIBLE] >> Yeah. So this is a good discussion. I see this a lot is some people just get the itch and they want to get out there, and that's what that dethatching is really the best for is curing spring fever. 

[LAUGHTER] But it's really, really not necessary, and I think it does more harm than good. Now, thatch, if you have a lot of thatch, you do have to get rid of it. But we saw thatch problems kind of go away a long time ago when our fertilization rates came back down to Earth. So, if you over-fertilize your lawn, you can get something called thatch which doesn't go away, but really what most people are tackling and getting rid of is just dead leaf material from the winter. And that stuff goes away really quickly when temperatures warm up. So thatch is actually like a woody material. It feels like a bunch of woody stuff. That's what a dethatching machine does. But if you don't have that, if you have a lot of mushy things and it's just brown from the winter, you really don't need to tackle it. >> So, if you did have the woody material building up, where do you tackle? Multiple years of that stuff? >> It takes a long time to do. 

I would say, number one, stop fertilizing as much as you have been. >> Oh, it's from the fertilizing. >> That's how thatch accumulates. Thatch accumulates from over-fertilization, essentially. So I would back off on the fertility. And then I would continue dethatching. The other thing people like about dethatching if they don't need to is it often warms up the soil a little quicker so your lawn does turn green before you neighbor's do. Some people are into that. >> So, how long does it take to actually build up true thatch? It's not probably every year. It's probably every so many years. 

>> Yeah, you wouldn't need to do it every year. For sure. Yep. All right, I'm going to... >> What about a mulcher mower? Doesn't that thatch? >> No, mulcher mowers don't. So, thatch comes from stems. Mulcher mowers just put leaves back into the soil. Leaves are like 97% water and 3% nitrogen. So, it's just like a fertilizer. So the thatch builds up from growing too many stems, not too many leaves. 

So, the mulching mowers are great. Everybody in this room should be mulching, not bagging. All right, so I'm just going to go really quickly, and then I'll just open it up for questions because we don't have much time left. A couple products that are available that you can use during seeding. One is called, the active ingredient is Siduron, sold as Tupersan often. You can put this down to keep weeds out while you're putting out you grass seed. Another one that you can't put down at the time of seeding is Drive or Quinclorac. Now, this will take care of small crabgrass seedings. It's also pretty safe for new grass planting. >> What was the other one? Before that? >> Siduron is the active ingredient. 

Like reading the cereal box, you've got to look at the fine print. It has different... >> [INAUDIBLE] >> It won't be. I don't think. Quinclorac is sold as Drive. So these are two products that work pretty good with young plantings. So, I'll leave this up here while I talk about non-chemical renovations. So non-chemical would be to minimize that soil disturbance. Don't use Kentucky bluegrass. If you want to have Kentucky bluegrass use sod. 

Okay? Tall fescue or fine fescue are your best for non-chemical options because they germinate so much faster and out-compete the weeds. Kentucky bluegrass from seed sits there for so long that you can't really do much about it. So we have two publications about non-chemical or reduced chemical on The Learning Store called Do-It-Yourself Alternative Lawn Care or Organic and Reduced Risk Lawn Care. So, questions? [LAUGHTER] Let's start over here. >> One of the concerns for a lot of people is that we have too many lawns. We have created urban deserts for birds and wildlife. >> Right. >> And so I'm thinking that the chemical amendments to the soil pushes that even further because birds or other creatures that need to feed from worms and bugs and stuff are going to be even more disadvantaged. So one of the things that we started using is the cornmeal. >> Yeah, corn gluten meal. 

Sure. >> So, do you have anything to say about that? >> Yeah. Corn gluten meal is a good organic or alternative option for pre-emergent weed control, but it doesn't work when you're trying to grow new grass because it prevents all seeds from germinating. So, in a situation where we're not reseeding, that would be one of our recommendations, but because you want the grass seed to germinate, you have very few other options from that. You, in the green. >> First of all, you said Kentucky bluegrass, which I starred for my husband, and now at the very end you say no. >> Well, non-chemical because Kentucky bluegrass takes 21 days to germinate so you would have to sod it. >> So no on the Kentucky bluegrass then? >> Well, it's always more complicated. It's definitely not a wholesale no. If you're trying to out-compete weeds in the spring, it's going to be difficult with Kentucky bluegrass. 

Probably a better way to say it is plant the other grasses in the spring and wait until fall to do Kentucky bluegrass when there's less weed competition. But Kentucky bluegrass is a great grass once it's there. The problem is getting it there. >> Okay. Then when you talk about all this compost, I compost but I don't have near enough. >> To cover the lawn. Yeah, that's tough. >> Can you use peat? >> We wouldn't recommend peat. It tends to, when it dries out it becomes hard to wet. The municipal compost, we've been playing around with it, but there's probably too many rocks, and we've found glass in it, to really be comfortable putting on the lawn. 

There's distributors of compost on the show floor that are really high quality, but they tend to be more expensive. >> [INAUDIBLE] >> Milorganite is not going to be a compost. It's going to be more of a fertilizer. Yep. >> So you recommend just leaving -- let it lay? >> Yep, let it lay. >> [INAUDIBLE] >> Yeah. Madison parks is a blend, and it does change kind of ever year based on availability. But it has a lot of Kentucky bluegrass, creeping red fescue. It does tend to be a pretty good mix for the type of stuff we're talking about today. >> -- has a product... 

[INAUDIBLE] >> Yeah, the hydro-seeding. Sure. >> The seed has the fertilizer. >> Yeah. >> What do you think? >> Tell me what the seed is. That's the most important question is, is the seed the right type of grass?  If you have the information, find me on the web and send me the information. We just did that question yesterday. What about Canada green? It's this magical grass that does all these magical things. The marketing is overwhelming. Send me the seed label. 

I can tell you exactly how it's going to behave. But don't listen to the marketing. Yep. >> [INAUDIBLE] >> Yeah, that's the name for the University of Wisconsin Extension's publication depot. >> [INAUDIBLE] >> I just go to Google and type in The Learning Store, and it will come right up. >> If you want to put in a lawn with a mix of grasses, do you have a recommendation that's a mix? >> Yeah, it varies for every situation. So the question was, what's the best mix, basically? >> How do you determine what the best mix is? >> How do you determine what it is? So, again, sometimes it's trial and error for what works for your site. Rocky soils, dry soils where you don't get ice accumulation, I like tall fescue. 90% tall fescue, 10% Kentucky bluegrass. If you have low-lying wet areas, it's not going to be the best option. 

So I still like a lot of the Kentucky bluegrass with small amounts of fine fescue because we did see a lot of fine fescue death, but we might not see another drought like this for 30 years. So it's always hard. >> How about on a sandstone/shale hilltop? >> Tall fescue. Yep. Give it a shot. >> High compacted or high traffic areas. >> Yeah. High traffic areas you're always going to have trouble growing stuff. Probably the most specialty one is a grass called Poa supina, which is like $30 a pound, but it does grow in wet, compacted soils better than almost anything else. If you have shade, not too many grasses are going to grow in that situation very well at all. 

>> [INAUDIBLE] >> Yeah, marketing is really deceiving. Some of them are true. Like that one grass that I showed you, the Kentucky bluegrass in the picture, marketing will tell you it's really drought resistant, it is. Some of them are just marketing and you can't cut through it. So, again, probably since this is a small group, just send me an email and I can help with selection for this year. >> Application techniques for applying compost? >> It's not fun. It's basically shovel it and rake it. That's the reason most people don't do it. The companies are starting to bring on to market more of these top dresser type material that kind of, yep, but if you have an area, you still need mountains of compost to do it. So compost is most suited for smaller areas that you can do by hand still, which is one of the worst things about it. 

>> [INAUDIBLE] >> That's another seminar, ants. [LAUGHTER] Chris Williamson is our turf grass entomologist, and he's an ant expert. >> Does he have a seminar too? >> I'm not sure if he does, but he will respond to your email. >> What's his name? >> Chris Williamson. >> What about worm castings? I want to set up croquet. >> Oh, you've got bumpy, yeah. >> It's bumpy and it's hard to walk with a glass of wine. >> Yeah. [LAUGHTER] >> So what do you do with the worm castings? >> There's not good solution for that. There really isn't. 

Golf courses struggle with that. There's not chemical to apply to get rid of them. They're good, in the most part, but for bumpiness, they're just something you have to deal with. >> [INAUDIBLE] >> Yeah, Chris Williamson has done some of that. Angular top dressings, angular materials, they tend to go away. They don't like that, but it's a lot of work. If you want to put that effort into it, we can get you the resources to help with. >> Email you? >> Yep. All right, we're going to have to wrap it up. Thanks. 

Stick around if you want to ask more questions. [APPLAUSE]