Fair lawn public group in Times of Drought
Hello, I’m Aaron Patton, turf grass extension specialist at Purdue University, and today were going to take a look at this lawn and talk a little bit about drought. one of the things that we can think about when we’re faced with the drought is we can think about what kind of watering strategy we want to have in our lawn, and there are two main approaches that a home owner might take during drought with their lawn.
The first approach might be that they really like their lawn, they want to keep it nice looking and so they’re going to irrigate a couple times a week, two to three times a week to supply a little over an inch of rainfall or an inch of irrigation to their lawn. And then that’s going to keep the lawn green and growing during those dry periods. Now because of the cost of water or maybe people schedules and so on not everybody wants to water their lawn, or maybe don’t have the capacity to water their lawn because they don’t have an irrigation system so on.
And so some people may choose to let their lawn go into what we call a dormancy state where the lawn it turns brown during the drought and just from the lack of water. Now, what most people don’t understand is that when turf turns brown like this it’s not dead. A lot of people think that once turf turns brown it’s dead and it’s not. It goes into what we call this summer or drought dormancy. For most of our lawns in Indiana, Kentucky bluegrass, or in the greater Midwest Kentucky bluegrass lawns, they can survive five, six weeks without any rainfall at all in this dormant state.
But once we get beyond that, if we go five or six weeks without any significant rainfall or without any measurable rainfall then there is a point where the turf could start to die. And so we often recommend that if a homeowner has a lawn that is in drought stress and they’ve enter that period of five or six weeks without rainfall, that they would go out and irrigate once every one to two weeks with about a half an inch of water on their lawn.
The purpose of that irrigation is not to necessarily green up their lawn, but just to put some moisture down in the soil so that plant can survive an extended period of drought. Now one of the things you can do to check to see whether or not your lawn has survive from the drought is to get down and examine the lawn more closely. Now, when you look at an area of turf that’s largely brown, what you’re going to be looking for is to see if there’s any green leaf tissue down on the lawn.
Now in this lawn right here, although it’s mostly brown, if we examine closely we do see some green leaves. And one of the easiest ways to do this is the take your hand and kind of try to knock some of the brown leaves off. You should be able to find some green leaves in there. Now if you don’t find any green leaves it doesn’t necessarily mean that your lawn is dead.
It could mean that is just taking a little bit longer to recover from the stress but if you have had rainfall and you’ve waited a couple weeks and you don’t see any new green growth emerging it probably is an indication that your lawn has succumbed to the drought. Now another thing we need to think about in the fall when we are trying to recover our lawns from drought is what kind of turf grass species we have on our lawn. Some turf grass species are what we classify as a bunch type grass.
Here’s an example of a clump of tall fescue and tall fescue is a drought tolerant turf grass that we use in lawns that is known to do well during drought. That’s why it looks a little bit green where the surrounding turf which is mostly perennial rye grass or Kentucky Bluegrass has already turned completely brown.
The problem with tall fescue though, is it’s this bunch-time grass, and so although it will survive periods of drought, it doesn’t really have the capability to recover from that drought. And so what we’re left with is maybe some areas around this clump of tall fescue that have not survived, and since this is a bunch type grass it will not spread into those areas.
So when you’re lawn recovers if you notice kind of a patchy appearance then you might need the get out there and throw some seed down fill in those patches The rule of thumb is we like to have is if the spot is bigger than the size of your hand then it’s likely that its not going to fill in on its own you’re going to need to add some turf seed to that area to try to get that to recover your lawn.
During drought one of the things that homeowners will experience is that a lot of the weeds in the lawn will stay green when the turf in their lawn might turn brown. Many of these weeds are summer annual weeds that do really well during these hot dry conditions. Other weeds are perennial weeds that might have a very deep taproot system and be able to survive drought.
And so many homeowners will often want to go out and control these weeds during this period and so we need to give that some thought because that might not necessarily be the best time of year to control the weeds in the lawn. So let’s take a couple examples here. Here we have some broad leaf plant in the lawn and you see the lawn around it is brown, and these weeds are green.
So a homeowner might be tempted to go out and spot treat these weeds but that’s not necessarily what we recommend during the summertime. Many of these weeds we could potentially get some control of the weeds if we spray them this time of year, but because the leaves have a really nice waxy cuticle in the summertime and because they’re not moving nutrients and carbohydrates down, downward to the plant root system in the summertime a herbicide that we might use on them this time of year won’t work nearly as well as if we just wait a few months.
So, for a weed like this, rather than coming out and treating it today a perennial weed like this dandelion or like this broad leaf plant we’d be better off if we wait for the month of October when it was cooler. In the fall months to spot treat these weeds and then we’d have a lot better results than if we came out here this summer to control these weeds.
Okay, so we’re out here on our lawn and it’s summer time and it’s been drought stressed and you’re probably wondering, “What can I do to my lawn to help it recover?” One of the best things you can do to your lawn is to encourage some new growth with fertilization. There are better times a year to fertilize and so on.
One of best times of year to fertilize is actually in the fall, and by fall I mean September, October, November that time period. Now another thing that we can do this time a year is we can think about seeding.
The end of the summer, start of the fall is the best time of year to seed a lawn, and so, when you go out on your lawn, inspect areasif there’s some thin areas of the lawn that didn’t seem to recover well from the drought, then that the end of the summer, start of the fall is the best time to put some turf seed down in those areas.
That will give that seed several months to establish before the next summer’s drought. So that’s why we like to seed at the end of the summer, start of the fall because it gives the maximum amount of time for that plant to develop a nice deep root system be to be able to handle a potential drought the following year.