University Place

[gentle music] - Bruce Spangenberg: Okay, good morning.

I'm Bruce Spangenberg.

I'm a Horticulture Outreach Specialist with UW Extension in the horticulture department.

And today's program is "Wisconsin Lawn Calendar."

You should have a handout.

That basically identical handout is on our website.

That's in our fact sheet I put together last summer.

So, we have the electronic version.

You also have the paper version, and basically... the premise of that fact sheet, we're dealing with cool season grasses, which, you know, Kentucky bluegrass, fine fescues, perennial ryegrass, those are the dominant lawn grasses here in Wisconsin.

And the idea behind the calendar idea is to make sure you properly time the practices 'cause of what can happen.

You know, I also emphasize minimal use of chemicals.

If you time things at the right time, different practices that I'll talk about, it maximizes the benefit for the turf.

It also minimizes the chances of problems.

So, you're much less likely to have to deal with weeds or disease or something else that's gonna be an additional chore.

It's also possible chemical use, that type of thing.

And also keep in mind, and I'll emphasize as I go along, not every lawn-- You're not gonna do all these practices on your lawn in one year, and your lawn may not need any of these practices, certain ones that I talk about.

So, you need to match the practices to the needs of your lawn.

And I'll elaborate on that a little bit as we go along.

So, a couple of disclaimers I mentioned, there's a number of things that I'll talk about.

I'm not suggesting you're gonna do all these things on one lawn in one season, depending on what they are, and there are some natural conflicts that occur.

And again, I'll touch on this as I go along.

Primarily, if you're dealing with any kind of new seeding combined with an established turf, 'cause that creates a conflict if you're using a herbicide, 'cause most of the herbicides cannot be used on newly established turf, or they may damage seedlings that are germinating.

And things like fertilizer rates are going to differ.

Typically, they're gonna be much less on a newly seeded turf versus the established turf, and even your watering schedules a little bit different, 'cause you gotta take into account that young seedling versus established plant.

They have different needs.

And, of course, we have the weather.

Not much we can do about that, but you know, we suggest the optimum time to seed might be, you know, the first week of September.

Well, if it's 90 degrees and it hasn't rained in three weeks, it's probably not a good idea.

You might wanna wait a little bit.

So, sometimes you have to make a few adjustments based on those unusual extremes, either hot or cold, wet or dry, that type of thing.

So, we're gonna start out with spring.

And spring is a key time for our cool-season grasses for their growth and development.

And you basically set the stage for the season as you go along.

A lot of things that you do in the spring are gonna impact that turf right away, and they'll carry on throughout the summer, even into the fall.

And basically, what you want to keep in mind with spring, especially once the snow melts and the warm weather comes in, hurry up and wait, okay?

You don't wanna get out there too soon and start fertilizing, that type of thing.

And again, I'll talk about some of this.

You really want to gauge how quickly you do things in the spring on how your lawn's responding to the weather and where you are in the state.

Obviously, here in the southern part of the state versus the north, you're gonna see some differences, and I'll touch on that.

So, our spring calendar, there's quite a bit on here.

And again, it depends on some of your needs, but cleaning up debris is typically gonna be the start.

You know, how did the winter go?

You can rake up dead grass and debris that's accumulated.

And typically, your lawn looks kind of like the picture here.

It's spotty.

You know, I've got some areas that might be six inches high and dark green.

Another area like you see here that might be totally bare.

That might be a problem with ice over the winter.

It could be snow mold, some other things.

It may just be an area that's slower to respond.

So, give it some time.

You can do some raking.

If you're raking here in the spring and you're pulling up debris with a hand rake, that is not thatch.

I'll touch on thatch in a little bit.

A true thatch layer is much denser than that, but basically get the debris up and then start in with mowing.

We'll talk about mowing.

We'll talk about crabgrass control.

Obviously, that was a huge problem last year here in Wisconsin.

We'll talk about fertilizing and also core aerating.

Those are really the things to emphasize in the spring.

I've also listed establishment, overseeding, broadleaf weed control.

But you notice they're not highlighted.

They're kind of down at the bottom.

That's not the best time to do those.

You're really better off those to be an early fall activity rather than a spring activity.

But occasionally, you know, if you have bare soil, you just moved in, you got bare soil, you don't wanna wait 'til late September or late August, early September to seed your lawn.

You're gonna do it in the spring.

But you may have some drawbacks.

So, we try to emphasize, you know, the optimum time.

So, one of the things I'm gonna touch on right up front is mowing.

We kind of take it for granted.

But mowing has a huge impact on your lawn.

And again, that will carry through throughout the season.

It has a huge influence on problems, especially weed problems.

So, the lawn in this picture is simply mowed too short.

Weeds are starting to encroach.

That's one of the simplest adjustments you can make that has a huge payback, a huge positive impact on your lawn.

Simply raise your mowing height.

So, if we look at mowing guidelines.

Really three things to keep in mind.

The three questions are always how often do I mow, what mowing height, and what do I do with the clippings?

So, the frequency, base that on how is your grass growing.

You can't simply say, you know, every Saturday morning I'm gonna mow, or every Monday afternoon, whatever it is.

You base it on how is that grass growing.

We have what we call the rule of one third, which simply says, don't remove more than one third every time you mow.

So, in the spring, when it's cool and it's raining, you might have to mow every five days to keep up.

In the summer, when things dry out, you might have to mow every three weeks 'cause the grass simply isn't growing.

So, base it on how that grass is responding to its environment.

And then, your mowing height, one suggestion is if you have a rotary mower, just set it as high as it goes.

That's gonna be probably three and a half, might even be four inches, but try to get at least into that three-inch range and you'll see a huge difference.

The lawn will look better.

It'll have deeper roots.

It'll tolerate hot weather better, tolerate dry conditions better, and you'll have fewer weed problems.

So, again, that's a simple adjustment you can make.

Kentucky bluegrass is our dominant lawn grass.

The fine fescues are our dominant lawn grasses.

They prefer to be mowed higher.

Don't mow 'em at an inch and a half.

They're gonna struggle.

They're gonna be stressed.

And then, the clipping issue, return your clippings.

Assuming you're following that rule of one third, those clippings are pretty high in moisture.

They're gonna decompose pretty quickly and they're gonna recycle nitrogen.

I'm gonna talk about nitrogen here in a minute.

Putting your program together for the year.

You can basically get the equivalent of one fertilizer application simply by returning your clippings all season long.

You're recycling that nitrogen back into the turf.

Now, crabgrass is always another concern in the spring.

And again, last year was a banner year, unfortunately, for crabgrass here in Wisconsin, especially in the southern part of the state.

But the thing to remember with crabgrass, it's an annual weed.

So, every crabgrass plant you saw last year in your lawn is dead.

It died last fall.

It has to come back by seed this spring.

And it's a warm-season annual, meaning it likes warm weather.

So, it's gonna take quite a while for crabgrass to germinate.

You know, the first warm day in the spring, crabgrass is not germinating in your lawn.

And sometimes, people get concerned.

You know, "I've got to put that crabgrass preventer out because it got 60 degrees today."

You got a long ways to go.

The soil temperatures need to get up about 60 degrees and stay there for several consecutive days.

So, soil temperature versus air temperature takes a lot longer to warm up that soil in the spring.

And then, where crabgrass is gonna typically thrive.

It likes full sun and it likes a thinner open turf.

It likes to have sunlight hitting the soil.

That gives its upper hand as far as germinating and getting established.

So, if you see something like this, like we saw a lot of last year, all these light green grasses are crabgrass plants.

Unfortunately, that's in also in a lawn that's been mowed excessively short.

So, that's, you know, basically why that crabgrass is flourishing because a lot of light is hitting the soil.

So, our management program, if we start out for crabgrass, if we start out with the cultural side, by far the biggest impact is raise your mowing height.

That's the number one thing you can do whether you do anything else at all.

For crabgrass management, raise your mowing height.

You'll see a big difference.

Avoid cultivation in the summer.

So, if you're gonna do some overseeding, if you're gonna do some dethatching, those kinds of things, ideally you're gonna do that in the cool weather when the lawn responds quickly.

If you do those kind of things in late June, early July, the cool season grasses are very slow to recover.

Crabgrass is thriving, so it's very likely to invade.

And then, sound for irrigation and fertilizing, and I'll talk about fertilizing here in just a second.

Fertilizing has a huge impact on weed control because basically all our lawn grasses, especially Kentucky bluegrass, needs nitrogen to flourish.

And you give it some nitrogen within reason.

And we'll talk about rates, that grass will be thicker.

It will naturally resist weed invasions.

So, again, that's one of your defenses against weeds.

Fertilize your lawn, mow it higher.

Now, if you have a situation where you had a tremendous amount of crabgrass in the past and you're working on trying to get your lawn thicker, you may need to come in with a preemergent herbicide this spring.

And if you go to garden centers, they have a lot of these available.

If they have the do-it-yourself three or four-step program, they always include a preemergent crabgrass control.

If you're hiring lawn care, you're pretty much guaranteed the lawn care service is also gonna put a preemergent down.

Now, the way a preemergent herbicide works is it actually kills the root of the crabgrass plant as it comes out of the seed.

It doesn't sterilize the soil.

But it has to be down on the soil before that crabgrass seed germinates, so you can't wait and see.

Crabgrass starts to germinate and then put the herbicide down.

You missed it on the timing, so.

Does your lawn need a preemergent herbicide?

It just really depends on the history.

But again, if you focus on the cultural practices, you can get away from having to use the herbicide.

On the other hand, like I said, last year, if you had a tremendous amount, you know there's a lot of seed there this year, you might wanna use a preemergent, work on the other cultural practices.

So, hopefully next year then you won't need to use the preemergent.

You can cut down on the chemical use.

Most likely, you're gonna find it combined with fertilizer.

I'll talk about fertilizing here next.

And I put the forsythia bloom on the slide there.

You also see a picture of forsythia on your handout.

There's that connection.

And again, this is all based on temperature in the spring.

But when forsythia are blooming, that's an idea of now you might want to think about putting preemergent down.

Typically, crabgrass is gonna germinate after forsythia blooms.

So, really a better signal would be the blossoms are starting to drop on the forsythia.

That's about the time you wanna put your preemergent down.

So, that's just a clue.

Now, there are postemergent herbicides available.

And what the difference is, a postemergent means the crabgrass plant already is up.

You spray it on the plant and you kill it if the herbicide worked properly.

Most of those work best when the crabgrass plant is very small.

If the plant's already gone to seed, established plants like you see here in the picture, at that point, it's really questionable whether you need to use that herbicide.

Probably won't work real well.

And the other thing is, a few weeks later, as you get toward the end of summer, first part of fall, that crabgrass plant is gonna die on its own anyways.

So, if crabgrass gets away from you one year and your lawn is just infested, remember, they all die.

They're gonna die in the fall.

You start over next year.

So, just, you might have to tolerate it there for a few weeks and then move on rather than messing around trying to apply another herbicide.

That's really not necessary.

And again, you're using more chemical than you need to.

Okay, so fertilization.

The goal is the lawn on the left.

Your worry is you're gonna do something, end up with the lawn on the right where you've got some problems there.

So, basically, when we deal with fertilizing, don't be afraid to fertilize your lawn.

Do it in moderation.

We'll talk about rates and how to choose a good fertilizer and when to put it down.

What happened on that lawn on the right-hand side, there's some miscommunication with the lawn care service and a homeowner.

So, a fertilizer was applied.

The weather was cold, nothing much happened.

The homeowner insisted the lawn care company come back and reapply, which they did.

Still stayed cold, nothing happened.

The homeowner put a third application on.

Then the weather got warm and it rained, and you can see what happened.

So, be careful in the spring, anytime, but especially in the spring.

Just wait for the weather.

Wait for your lawn to start to grow before you fertilize it.

So, when we talk about fertilizing and "How do I fertilize my lawn," is really a three-part question.

You need to pick out a good fertilizer.

You need to focus on the rate or how much you put down.

And then, when do I put it down?

That's really your question.

So, as far as types of fertilizers, we have two categories.

And I'll show you some examples here in a second.

But we have what we call fast or controlled release, which essentially, when you deal with a fertilizer of any type, when you first take it out of the bag and put it down on the soil, it's not instantly available to the lawn.

It needs to go through some kind of conversion to what we call nitrate, a form of nitrogen.

That's what the grass takes in.

So, a fast release does that very quickly, which is good in one sense.

The lawn gets the nitrogen.

But the downside is you can cause overgrowth.

You can burn the grass, those kinds of things.

Controlled release has some mechanism to delay and slowly make that nitrogen available to the grass over a longer period of time.

So, typically, that's what we suggest for turf, is to give that small amount over a long time rather than all at once with a lot of nitrogen.

We talk about rates, how much to apply.

As I mentioned, clippings recycle some nitrogen.

So, automatically, if you're returning your clippings all season long, you are putting down a fertilizer application that's spread out over several weeks.

Keep in mind that lawn in the shade requires less nitrogen than a lawn in the sun, and sometimes people do the opposite.

A lot of our turfgrasses aren't real well-suited for shade.

They struggle.

So, then people decide, "Well, it's not doing too well.

Let's give it another shot of nitrogen."

That's actually the worst thing to do.

Turf in the shade simply doesn't need as much nitrogen as in the sun.

And then our timing, we focus mostly on spring and fall.

Avoid the hot weather months.

Again, we're dealing with cool season turfgrasses.

So, I mentioned fast and controlled release.

Here's some examples of fast release and controlled release.

Now, if you buy a fertilizer and you look at the package, the bag, the box, whatever it comes in, typically it's a bag with lawn fertilizers, you'll have what we call a guaranteed analysis section on the label, and it will list all these different nitrogen sources that are used to make that product.

So, you may see a combination of fast and slow release or controlled release, but you want to focus on having more of the controlled release in there.

Typically, there's a little bit of fast release just so you get some green up.

Like, just like when you hire a lawn care company, and they may use a quality controlled-release fertilizer, but they're also gonna add a little bit of fast release because you pay them to fertilize your lawn.

You wanna see some results.

You know, if they say, "Well, wait two weeks," you're thinking, "Well, what happened?"

A little bit of extra fast release there will get some quick green up, not excessive.

And then the controlled release kicks in later.

So fast-release sources have been around for quite a while.

Urea, ammonium nitrate, ammonium sulfate are the three most common.

Urea is probably the most commonly used on lawns.

They have a very high analysis, very high percent nitrogen.

They also have a very high what we call a "salt index," which is what burns plants, burns root systems.

So, that's a major drawback.

So, if you're gonna use a fast-release source, you do it in moderation.

Controlled release, lots of examples here.

Ureaform, it's been around for a long time.

Sulfur-coated urea, and there's a lot of these polymer-coated ureas now, basically have a coating on them that slowly breaks down and allows the nitrogen to be released to the grass.

IBDU has been used a lot on golf courses.

It's abbreviated for obvious reasons to try to spell that and pronounce it.

But isobutylidenediurea is a compound basically.

Activated sewage sludge or Milorganite is another one that's been around a long time.

It's a quality slow-release product, does not have the contaminants that it once had from industrial waste that might have been in there.

And then most of the organic fertilizers are gonna be slow release or controlled release.

And one of the ways you can determine that, when you look at the guaranteed analysis, you may see that last thing listed there, water insoluble nitrogen, or it may say capital W, capital I, capital N. That's referring to, again, a nitrogen that's very stable and slowly breaks down.

A lot of these controlled-release sources rely on bacteria in the soil to slowly break them down.

Some, it's just a function of moisture and time.

But they do cost more.

That is a drawback.

But it is money well spent because again, they're gonna give that lawn smaller amounts of nitrogen over a longer period of time.

And what you don't wanna do in the spring is you don't want a big flush of growth, 'cause a lot of times, you know, there's competition.

I want the greenest lawn on my block.

Dark green is not necessarily better than medium green, so again, moderation.

We'll talk about the rate here in a second.

So, look at fertilizer sources.

Look closely at what's in that product.

And again, if you lined up fertilizers based on price, what you'd probably see if you went back and looked at the guaranteed analysis, those on the low end of cost are probably very high in fast release.

Those on the high end of cost are probably very high in controlled release.

And there's always some exceptions in there.

But I would emphasize again, if you're looking at the health of your lawn, it's money well spent.

Spend a little bit extra money in that fertilizer, you're gonna see some big dividends as far as what it will do and the problems that you avoid.

Like that one lawn you saw with all the dead grass on it.

So, specifically then in the spring, what do we do with our fertilizer program?

Timing-wise, the easiest thing to do, the best recommendation is base it on what is your lawn doing.

And ideally the best time to fertilize it would be after the second mowing.

Okay, so rather than say, "Well, I'm gonna fertilize on May 1 or April 30 or May 15," wherever you are in the state, base it on how that lawn is growing.

So, some years, that's gonna be possibly late April.

Other years, it's gonna be mid May, just depending on how the season goes.

But essentially, there's enough nitrogen around when lawns break dormancy in the spring, they don't need extra.

So, once they kind of-- things get more uniform on your lawn, you mowed it a couple of times, that's usually a good time to fertilize it.

Now, if you go back to when I talked about the preemergent crabgrass control combined with fertilizer, that timing is still good.

You're not gomma have crabgrass germinating at your second mowing.

It's gonna be much later than that.

So, if you're buying the combined product, which is typically how you're gonna find those preemergent crabgrass herbicides, fertilize at the same time.

Do it after the second mowing.

That would be perfect timing here in the spring.

As I mentioned, use controlled-release fertilizers.

And then, our rate is gonna be about one pound of nitrogen per thousand square feet.

If you look at most fertilizer products, they'll have, like, a setting guide on there.

It'll say, you know, if you have a Scott's spreader or a whatever company spreader, use setting D or whatever it is.

Normally, that's gonna be calibrated to be about one pound.

Now, you can do the math.

I hesitate to do math in front of a group, especially in the morning, so, we're not gonna go through that.

But you can go through that process.

But most products now, most companies are buying into that one-pound rate.

Some of the controlled-release products might be slightly higher than that, which really is not a big issue.

You know, if it ends up being a pound and a quarter, even a pound and a half, if it's a high quality, high percent controlled-release fertilizer, that's fine.

A pound and a half of urea, on the other hand, is not a good thing because you're fonna get a huge surge of growth and you're gonna have some problems.

What happens in the spring?

You know, I mentioned the grasses.

That's a good time for them.

They're revitalizing there.

It's an active growth time.

But if you put on too much nitrogen, you will get top growth, dark green grass.

You're mowing it every three days.

But that's at the expense of the root system.

And that's gonna haunt you the rest of the summer.

So, that's why moderation, use controlled release, wait for that grass for that second mowing to time it right in the spring.

Now, a couple other things here.

I mention thatch now, and I have it in that handout.

Talked about core aerating.

I mentioned though, if you're raking your lawn first thing in the spring and debris easily comes up, that's not a true thatch layer.

True thatch layers like you see here in the picture, it's a dense layer of living and dead material.

And it's really not clippings, it's root system.

It's stolons and rhizomes.

And Kentucky bluegrass has rhizomes.

So, you get a lot of organic material and a very dense layer on the surface.

And as it gets thicker, what happens is most of your living grass plant roots are now in thatch rather than in the soil, and they're gonna be stressed much more.

It's a very good environment for diseases, insects.

It's difficult to fertilize, difficult even to water sometimes when you get a real dense thatch layer.

So, the most common cause of thatch is soil related.

And typically a classic scenario, and we see a lot of this in the southern part of the state in residential areas, you have a fairly heavy clay, and that may be part of the process when the home was built.

A lot of the good topsoil disappeared and you're left with clay subsoil, or poor clay fill that was brought in.

That might be compacted, and you compound it by overfertilizing and overwatering.

We see more serious thatch problems like in this picture on sodded turf rather than seeded.

And the reason is when you put down sod over a poorly prepared soil, you brought in this established plant, may even have a little bit of thatch with it, now you set it down on this clay and the roots simply don't go down.

They go lateral or they come up, and you get this layer that gets thicker and thicker, and it gets harder and harder to manage that turf.

So, when we talk about thatch and you see different recommendations, they'll talk about dethatchers you can rent and you can tear the thatch out.

You're not addressing the cause.

That's why we really suggest core aerating rather than dethatching as a better long-term solution.

So, here's an excessive thatch.

This is actually an individual several years ago brought me the-- We talked on the phone and they brought me a sample.

They literally brought me a box of their front lawn.

They lifted it right off the soil thinking they had a grub problem.

They actually had a really thick thatch layer.

This was like an inch and a half, a really excessive layer.

And what had happened, it was a sodded turf over a compacted clay, and they were watering it with an in-ground irrigation system too much, and also fertilized it quite a bit.

But what happened now is basically all that root system was no longer anchored in soil.

It was all intertwined with thatch in a thatch layer.

So, the solution is focus on the soil issue.

So, that's why on that spring calendar I put in core aerating.

Spring and fall is a good time to aerate.

I mentioned it now here in the spring part of the schedule.

If you had a choice to do it once a year, I'd probably do it early fall rather than spring.

If I had a sodded lawn and I knew I had a soil issue underneath, I would do it spring and fall.

Do that for a few years at least, to try to get things going in the right direction, because basically what core aerating will do is correct the cause, but it also degrades the thatch layer.

It helps increase microbes 'cause one of the problems you have when you have that compacted soil and that wet environment, you have very few beneficial bacteria to degrade that thatch layer, so that's why it's accumulating.

As you aerate, you turn that scenario around.

You increase the oxygen, better microbe environment, better root environment.

So, now your turf roots go deeper and your microbes break down the thatch that's sitting there.

So, really good practice.

And even if you don't have a thatch layer, periodically aerating your lawn is money very well spent, whether you rent it or hire somebody to do it.

Anything you can do to help your root system enhances your lawn, you know, and in the long term, helps reduce chemical use, helps hold off some of the problems or avoid some of the problems that might occur.

So, the process on the bottom of that aerator, you have these hollow tines that go through the thatch into the soil.

They pull that core or that plug up like you see on the right-hand side there, and you wanna leave that on the surface.

That's what we call top dressing.

So, now you place some soil on top of the thatch, the bacteria build up, and they start to degrade the thatch from the top down.

You've also made the holes in the soil through the thatch.

So, microbe populations build up.

And now it starts to degrade the thatch from the bottom up.

Plus you've improved the soil better for the grass to grow.

So, it's something that's really, well, highly recommended I should say, as far as lawn care is concerned.

And if you're looking at an overall budget, you might even wanna skip a fertilizer application and spend that money on aerating.

Or go in with your neighbors, rent an aerator and have all your lawns done in one morning, and it's really something that can benefit.

But in particular, if you know you have a sodded turf, you know, a very common scenario, it's a sodded front lawn, a seeded backyard, that sodded front yard is gonna see thatch problems a lot more readily than that backyard.

And that's where the aerating comes in as a major benefit.

Okay, now we move to summer.

And basically, cool season grasses in summer, it's a slow time.

Depending on how bad or how severe, however you wanna word that.

Some people like really hot summers, but the hotter and drier, the more likely that turf is to slow down and even go dormant.

Now, sometimes we get a cool, wet summer and grass stays green and you're mowing it consistently all summer, but we're gonna assume you're gonna get warm weather in there.

So, it's kind of a time off for your lawn.

Not a lot of activity here.

So, most of our cultural practices, we're avoiding.

Now, as we get toward late summer, that's a key time to prep for doing things like overseeding or renovation that you might be doing in September.

So, our calendar here is pretty short.

Irrigation and mowing.

So, again, I already touched on mowing.

Also scouting for insects, in particular grubs.

That's sometimes a concern in the summer.

Now, I put a question mark on there, broadleaf weed control and fertilization.

For the most part, avoid 'em.

If you're gonna fertilize in summer, that would need to be on an irrigated lawn.

And you are inviting problems, you know?

So, if you put a good quality controlled-release fertilizer down in spring, like I said, I would avoid summer.

And your next time to fertilize is gonna be about Labor Day, which will be coming to here in a few minutes.

On the other hand, if you have a really high-maintenance turf, you could fertilize it in, let's say, June.

You know, some schedule-- or some recommendations say, "Follow the seasons."

They'll say Mother's Day, Father's Day, Labor Day.

If you're gonna do that Father's Day time, definitely controlled release and probably use it at a lighter rate than the one pound.

But for the most part, I would skip it just to avoid problems altogether.

As long as you've done that May application.

So, as far as watering, a couple recommendations.

We say water to the depth of the root system.

That's simply to take into account if you just seeded a lawn, you have to water more frequently and not as deep 'cause the seeds are up close to the surface.

If you're dealing with an established turf, you're gonna water less often, but you're gonna water deeper because the roots are down deeper.

So, that's why you make the adjustment.

But that's why I mentioned at the beginning, you do have a conflict.

And I'm gonna get into overseeding here in a couple minutes.

If you overseeded, you need to water it, if it hasn't rained, more frequently to help those seedlings along compared to the established turfs.

You have kind of a mixture there.

So, always go on the side of the new turf, the seeded turf.

But assuming you're gonna water, some suggestions here as far as when to water.

What we call "foot printing," when grass starts to wilt, and you walk on it, it does not bounce back right away.

Your footprints kind of stay there.

Usually gets kind of a dull look to it, a darker, dull look.

That's telling you it's time to water it.

What you don't wanna do is wait until it turns brown and then decide to water it to make it turn green again.

Even though it looks better, if this is the heat of the summer, you've actually stressed that turf.

Because to go from brown to green requires energy that the plant has inside of it.

Summer is not a good time to replenish that energy for cool season grasses.

So, even though you made it turn green and it looks better, you actually drain more of its reserves away.

And if you do this a couple times, so if you make a turn green, dries out again and it turns brown, you water it again, turns green, eventually it's not gonna turn green 'cause you burned it out.

So, one recommendation if you don't wanna water, make that decision early on.

Mow as high as you can, and our cool season grasses can tolerate dormancy in summer.

You know, it's perfectly acceptable for a bluegrass plant to stay dormant for a month.

It's not gonna die.

It is brown, but it's not gonna die.

So, if you're dealing with watering, you don't wanna spend the money on the water bill, start mowing as high as you can in June before the hot weather rolls in and let it go dormant, but don't bounce back and forth.

Be careful not to overwater.

And the classic, again, we see is when someone has spent the money to put in an in-ground irrigation system.

They sodded their lawn.

They wanna take advantage of the system.

They set it improperly and the lawn is too wet.

This is a lawn that this individual had sodded.

After two months, they commented, when they walk on it, they could feel it shifting under their feet.

The reason: It's sitting in water.

It never had a chance to dry out.

You can temporarily sod on concrete and keep the sod alive, but eventually, it's gonna have some serious issues.

So, let the soil dry out before you water again.

This one, again, way too much water.

Now, I mentioned grubs here.

Just because that is the most serious insect problem, we're gonna see if we do see an insect problem on lawns here in Wisconsin.

Grubs like full sun to lay their eggs.

So, the adults are beetles.

They're looking for warm turf, full sun areas, and they need moisture in the soil.

So, if you happen to have the irrigated lawn in the hot or the dry summer in July and early August, all your neighbor's lawns have gone dormant or half dormant.

Yours is nice and green, and then it gets to be the end of summer and your lawn's infested with grubs and your neighbors have none, that's why.

That was an oasis for those beetles to go to lay their eggs.

Now, if we have a rainy midsummer and all the lawns have adequate or equal amounts of moisture, odds are those beetles are just gonna disperse and lay their eggs randomly, and you won't likely see a heavily infested lawn with grubs.

So, if you have brown areas, what you wanna do is check where the brown meets the green and try to pull that grass back.

Now, that picture on the left, the raccoons have done it for you.

Raccoons and skunks will come in and tear up lawns, looking for grubs to eat.

And unfortunately, they don't count.

So, they don't say, "Well, this lawn's infested.

This one isn't."

Raccoons just start digging and looking, and they might tear up your lawn even though there's only a couple grubs in there.

But typically, if you're gonna look in that root zone, you normally have about ten grubs per square foot.

That's usually about the level where you're gonna see lawns turning brown.

So, really, we wanna emphasize here, make sure you have a grub problem before you consider applying insecticide.

Don't, here in the spring, by a four-step program that includes an insecticide.

There's no way you can predict that right now you're gonna need that.

Odds are you will not need it.

Wait and see if grubs start to show up.

You can treat accordingly, but don't just routinely put an insecticide down for a problem that does not exist.

Again, it's a good way to save chemical use, reduce chemicals out in the environment.

Normally, if you're gonna see the grub damage, it's gonna be late summer, maybe early fall.

So, check you got areas turning brown.

You're not sure what's going on.

Try to peel that turf back and look where the brown meets the green.

That's probably where you're gonna see those grubs waiting for you there.

There are a number of grub materials to consider.

And I'll show you a couple examples here in a second, but basically read the label, follow the label directions, whether it's an organic control or a synthetic, it is considered a pesticide.

Make sure you follow the label directions on that.

And the material has to get into the soil where the grubs are.

So, not only do you wanna water the material in after you apply it, it's also a good idea to water before you apply it to get some moisture in that soil so the insecticide doesn't just dry on the soil surface and it never gets down where the grubs are.

And then, monitor results.

The reason I put that comment on there, don't expect brown grass to turn green just because you treated for the grubs, because the grubs have eaten the roots away.

It's gonna take some time for that turf to recover.

You might have to do some more reseeding in the fall.

And grubs also do not instantly die when you apply an insecticide.

It might take 10 days, 14 days.

So, if you go out there the next day and check and you see that grub's still sitting there, that's fine.

It's probably gonna stop feeding pretty quick and then slowly dissipate.

But a couple scenarios on insecticides.

There are a number of materials out there.

I just listed three of 'em here as an example.

If you're using a synthetic insecticide and you take what we call the "wait-and-see approach," wait and see if the grubs actually show up, the material trichlorfon, which is sold as Dylox, or it might say 24-hour grub control or quick-acting grub control, that's an insecticide that works very quickly and also degrades very quickly in the soil.

It doesn't persist.

It's also not considered highly toxic to earthworms.

So, it's not-- Even though it's synthetic, it's pretty environmentally friendly.

And again, the way you would use that is wait and see.

I've got grubs, I found them, I apply the insecticide, I water it in, and I'll get results.

I'm not gonna put it down two weeks ahead of time because it's gonna dissipate in the soil.

A couple of organic or biologicals, there's another spell check challenge there, the Heterorhabditis bacteriophora.

We just call 'em Hb nematodes.

Nematodes are living, microscopic worm-like organisms.

And there are some that are parasitic on white grubs.

They don't harm earthworms, but they go after white grubs.

So, you can apply these to your soil and get biological control.

The challenge is you're handling a living microbe, basically.

So, if it sits on a hot shelf in your garage, they may be killed before you apply 'em to the soil in your lawn.

So, that's always a challenge with some of these biologicals.

They work very good in a lab setting or a field test setting, but it's hard to replicate them into a product you can package it, ship it, get it to somebody, and then have them use it and have it work.

We also have a BT.

Some of you, I'm sure, are familiar with Bacillus thuringiensis, especially the kurstaki variety that's used on caterpillars.

We have one here.

The GrubGone is a typical product, but the BT galleriae is actually a bacteria that you can apply to the soil that will kill grubs.

So, it's an alternative to synthetic insecticides.

And there are some other options out there as well.

There are some materials that you put down sooner 'cause they'll last longer.

I would question those of you in particular, if you've never had a grub problem, don't start applying those insecticides when you don't need to.

It's not a environmentally sound way to manage turf pests.

But always read the label directions.

Monitor your lawns quickly.

If you've had grubs in the past, you know, be on the heads up there.

They're probably gonna show up again.

They might show up again.

Be ready with one of the appropriate insecticides, whether it be synthetic or organic.

Now, as we get to late summer, and typically we're pretty safe saying the second half of August, unless it's a really cool, wet summer.

But basically, we're looking at preparing for that early fall, which is the next really key time for our cool season grasses.

So, it's a good time to control perennial grassy weeds, and I'll show you the two most common ones here in a second.

Control 'em in August.

Reseed those areas in early September.

It's also the time to prep for renovation, or if you're establishing a new lawn, any type of soil work, it's a good time to work on it at the end of August.

Get rid of the weeds and then be ready to seed right about Labor Day or shortly after.

Continue with irrigation and, of course, white grub control.

White grubs can show up into September, so keep monitoring your turf.

Just depends on how that particular year played out.

So, if you deal with perennial grass weeds, the two most prevalent ones, one is tall fescue, especially here in the southern part of the state.

We see a lot of this, and this is very often confused with crabgrass.

So, tall fescue is a coarse grass.

Now, there are also are some finer tall fescues that can actually be seeded as lawn grasses.

But the older, what we call the pasture types, like you see here in the picture, a very coarse, very wide leaf blade, very tough leaf blade.

It's hard to mow, and you get these very distinct, patchy, clumpy-looking grasses.

As I mentioned, it's often confused with crabgrass.

If you happen to see this right away here in April or early May, you've got this established clump of grass in your lawn, there's no way that's crabgrass.

It's way too early.

It's gonna be a perennial.

Most likely, it's gonna be tall fescue.

Tall fescue has very good drought tolerance.

And again, that bunch-type grass.

The other one we see a lot of is creeping bentgrass.

Now, creeping bentgrass is not a weed on a golf course.

That's the dominant grass on putting greens and a lot of fairways.

But in a lawn, what tends to happen is when you mow it with a rotary mower, it's pretty shallow rooted, it easily tears up.

So, you get these patches or clumps of very soft grass, a different shade of green than your bluegrass lawn typically.

And then when you mow it, very often parts of it get torn up.

Creeping bent has stolons, which are basically stems that creep along the surface, and if you break those off and move it with your mower, it does spread, so you get one patch, pretty soon you got four patches in your lawn.

But one of the signals, if you see a lot of creeping bentgrass, you're probably on the high side as far as nitrogen and irrigation 'cause it likes water.

It's fairly shallow rooted.

It also likes nitrogen.

So, you can look at that and say, "Well, maybe if I adjust my fertility, "that will help prevent this plant from coming back.

"Now, it is a perennial, so I have to do something with it."

You know, I mentioned earlier all the crabgrass plants we saw last year are dead.

They're not coming back except by seed because they're annuals.

Tall fescue and creeping bent are perennials.

They don't die.

They could die, but they rarely die.

So, they're there right away in the spring, and they start to grow.

So, your options here, hand pull 'em or dig 'em out.

If you've got one or two patches, that's the best recommendation.

Don't start messing around with herbicides.

Tall fescue is pretty shallow rooted.

It comes up pretty easily.

Creeping bent is also shallow rooted.

Just be aware of those stolons as you pull it up.

It may break apart.

Get all that material out of there because those little pieces will regenerate more creeping bent.

Your herbicide options are pretty limited.

Nonselective herbicides that don't leave a residue in the soil.

So, something like glyphosate, which for years was sold as Roundup, it's got some other trade names.

There are some other products that are called Roundup that don't contain glyphosate, so look closely at the label.

What you're looking for is a nonselective grass killer that does not have a soil residue that's gonna impact seeding.

So, look carefully at the labels.

But primarily, when you do this, if you've got a larger area or even a small one that you hand pulled, you have to do some reseeding afterwards.

So, that's why we say late-- mid to late August is a good time to address the weed.

And then, early September is a good time to reseed.

So, get the area prepped up.

Be ready to seed once we get past Labor Day.

So, that gets us into renovation.

Early fall is a prime time to renovate.

Late August is a good time to start prepping for that.

So, what two things you kind of look at, if I've got an area like this lawn, and if you're wondering, that's not my lawn, by the way, but I got this dead lawn here, mostly dead lawn.

What do I do next?

There's really two things to look at, two factors.

First of all, how much desirable grass is present?

So, if you've got desirable grass, then that can kind of steer you one way or the other as far as how you're gonna renovate that.

'Cause I have quite a bit of decent grass, maybe all I need to do is do some overseeding.

I don't have to tear it all up and start over.

On the other hand, if I see very few desirable turf plants there, I may as well just totally start over.

Just get rid of everything and do what we call a total renovation.

But the other factor is what's the condition of my soil?

You know, I mentioned that scenario where we see a lot of poorly prepared soil prior to establishment, especially with sod.

And then I got a serious thatch problem.

I got a compacted soil underneath.

If I have terrible soil conditions and I have very few desirable turf plants left, I may as well just start over.

It's gonna be more work initially, but I'm correcting the soil, and then just start like I'm seeding a brand-new lawn.

On the other hand, if my soil is actually in decent shape, this particular lawn in this picture actually died from drought.

The soil was fine.

It was just an unusual prolonged drought and the lawn died out.

I really don't have to do much with the soil.

I just need to get seed into that soil by overseeding.

So, I can take some different routes with preparing that surface and then doing some overseeding.

I don't have to tear that whole thing up and start over.

But if-- [clears throat] Excuse me.

If you know the soil is bad, you need to tear it up, amend it, and then go forward.

So, considering those two things, this is very often what we see.

You know, I talked about that, especially the sod over the poor clay.

So, the two pictures you see here, the one on the left-hand side, you notice the lower left is thinned-out grass, the upper part, the neighbor's lawn is still pretty green.

And you got that line going through there at a diagonal.

That line is the lot line.

The same lawn care company fertilized both these lawns on the same day with the same material.

The difference is the lawn in the foreground has terrible soil underneath.

The neighbor's lawn actually has pretty good soil.

So, what you see on the right is what we call soil interface.

That's a section that's been dug up.

You see the lighter-colored soil underneath.

That's clay.

You see that very distinct dark band sitting on top of it.

That's either a little bit of topsoil that someone put in there prior to establishing, or that's simply the soil that came in with the sod and they placed it down.

But anytime you see a very abrupt change like that from a good, dark loam soil to a clay soil underneath and there's virtually no transition, that's gonna be a nightmare for plants because water is not gonna move readily through that interface.

So, what's gonna happen to my roots on my grass plane, especially when I sod it, it's gonna hit that barrier and it's gonna go horizontal, and it's gonna go backwards up.

I'm gonna start creating a very thick thatch layer.

I'll have virtually no roots going down in the soil.

And I'm gonna see a lot of problems.

So, the way to avoid that is amend the soil ahead of time prior to establishment.

If I know I have the interface, but I still have decent levels of acceptable grass, that's where the aerating comes in, where I can gradually solve that over time.

So, factor all those things in.

As we move to fall then, this is our key time for almost everything.

Good time for grass growth, good time to fertilize, good time to establish turf, good time to aerate, renovate, all kinds of things.

So, as we move from late August into early September, through September into October, the weather's getting better and better for cool season grasses, so they're gonna respond very well.

The other big benefit as we move into fall, we're not gonna see things like crabgrass.

Crabgrass likes warm weather.

Crabgrass is not gonna germinate in September.

So, if I establish my lawn at the end of August, first part of September versus trying to establish it in May, I'm gonna see much fewer problems with weeds with that fall establishment versus spring.

So, my calendar then, establishment, renovate, repair.

I'll touch a little bit more on the renovation.

Fertilization, just like I talked about in spring, we do it again in the fall.

So, if you wanna focus on two key times to fertilize your lawn, after that second mowing in spring, and then about Labor Day.

Use a quality controlled-release fertilizer.

And I'll come back to that here in a second.

I haven't talked much about broadleaf weed control.

September is an ideal time to control broadleaf weeds.

Most of those are perennials.

And they respond very well as far as being controlled if you're using a herbicide at that time.

And then core aerating, of course, I already touched on.

September, October, good times to aerate lawns.

So, if I'm putting down seed, whether it be overseeding or starting from scratch with a brand-new lawn, this is your opportunity now to pick the best grasses that you can.

So, use named cultivars, choose named cultivars.

When you look at seed packages, you will see... It'll say Kentucky bluegrass, for example, and it may list two or three cultivars underneath there.

You're gonna pay more for named cultivars.

But just like with buying controlled-release fertilizer, it's money very well spent.

If you're going through all the time and effort to establish this lawn, now's your opportunity to get the best grass material you can out there.

So, we call it a blend when you have different cultivars of the same species.

It may also be a mixture.

You may have bluegrass with fine fescue, bluegrass with ryegrass.

More genetic diversity, a lawn that can withstand problems a lot better than just one cultivar out there.

NTEP, that NTEP, National Turfgrass Evaluation Program, that's what most seed companies use to base their decisions on what grasses to put in their products.

That's a nationwide effort with the USDA and the land grant universities, including right here at UW, where there are plots put out, where they evaluate cultivars, new ones compared to the existing ones.

And then, those are-- The information there is used to make decisions on the best seed products to put out on the market.

So, if I'm overseeing the thin lawn, pick a good grass.

I'm doing it here late August, early September.

The key thing is good seed-to-soil contact.

So, you can hand rake, you can rent a dethatcher.

But you can also use slit seeders.

These work extremely well if you're trying to overseed into established lawns.

Again, you're assuming the soil is in good shape.

Here's one type.

You put the seed in that hopper there on the left.

And underneath, you see there's like a series of knives that cut into the grass and the debris into the soil.

This one's a little bit better.

You're probably gonna rent this or hire somebody to do it, most likely.

But you put the seed in the top there on the left, and you notice the machine is kind of tilted back on the right.

You have a series of blades and knives that cut into the grass and the soil, and there's, like, tubes running down there.

The seeds are planted right into those cuts.

So, the seed gets into the soil.

You can do this right through existing grass.

That's existing green grass that's thinned out.

And those seedlings now will come up inside your established lawn.

So, it's an outstanding way.

If you have a real small area, you certainly can do it by hand.

But if you're dealing with a bigger area, the slit seeders really come into play as being an exceptional way to do that.

My fall fertilization then, Labor Day, just like I said in the spring, controlled release at about the one-pound rate.

So, that has not changed.

And the only new thing then that I have not talked about is broadleaf weed control.

And broadleaf weed control, if you have dandelions, clover, ground ivy, whatever it might be, these are perennials that the best time to try to control 'em if you're gonna use a herbicide is in the fall because they're controlled more permanently.

If you spray 'em in the spring or apply herbicide in the spring, a lot of times, they kind of wilt and curl, but they don't really die.

You apply it in the fall, they actually take that herbicide into the root system and they actually do die.

So, you get more permanent control.

So, September into October, now here's another way you can minimize chemical use.

You have broadleaf herbicides available as liquids.

You also have available as granular mixed with fertilizer, the "weed and feed."

Use the liquid herbicide by itself.

Spot treat where you see the weeds.

This is a post-emergent application.

You're applying it to established weeds.

If you can see where they are, spot treat 'em.

If you just have grass and there's no weeds, there's no point in applying herbicide there.

So, you can minimize the amount of herbicide you put down on the lawn.

Read and follow label directions.

And no lawn talk is complete without ground ivy, mentioning it.

Two examples here.

Triclopyr is probably your best synthetic herbicide, and you can find it in a lot of different products.

An alternative that's fairly new is an iron chelate.

The product called Fiesta.

And there's some information on our website about this.

You basically give the ground ivy a very high dose of iron, and it works very effectively.

Right around the first frost and when the plant's blooming are the two key times to deal with ground ivy.

And then finally, late fall, just keep mowing.

Remove the excess leaves.

Fertilization is-- It used to be recommended, and it's very difficult to time it perfectly because you want the grass to slow down.

You don't want the soil frozen yet.

Most recommendations now have taken that late fall application out.

And the other thing I listed here, dormant seeding.

If you're gonna do dormant seeding, very risky.

Ideally what you do is put the seed down right before it snows.

So, you gotta time that.

Good luck figuring that out.

And then, you want the snow to stay there until spring.

[audience laughs] Good luck, okay?

So, if you have a little bit of seed, you don't really care, you can try it, but don't invest a lot of seed for dormant seeding.

Just wait until spring.

You're gonna be much better trying to do that.

So, we need to vacate the room for the next session.

Thank you for coming, and we'll talk to you later.

[audience applauds]