¶ Intro / Opening
Chris EnrothWelcome to the Good Growing podcast. I am Chris Enroth, horticulture educator with University of Illinois Extension coming at you from Mac Omb, Illinois, and we have got a garden bite for you today. It is an excerpt from a previous show when we sit down to chat with Duane Friend, who back then was a natural resources energy environment educator. Today, he's our climate specialist and state master naturalist coordinator. But we sit down and we chat with Duane about ponds.
Now when we were talking with Duane, I think we were about the end of the month of July. But April is a great time to start thinking about ponds, especially those ponds where you have been having trouble with weeds and algae and all other kind of things. And so we talk about aerators on ponds. We discuss a perennial problem of duckweed on ponds, and then perhaps a slight solution to some of those issues in creating vegetated buffers of some of those drainage areas that go into those ponds. So without further ado, enjoy this Garden Bite where we're chatting with Duane Friend about pond management.
¶ Aerators in ponds. Do they work? What about aerating ponds during the winter?
Ken JohnsonRight. So sometimes you see, like, aerators and stuff on pumps. Mhmm. What exactly are people using those for?
A lot of times, it's more for looks than anything. But, and and they are very aesthetically pleasing. You got those fountains shooting up water, that looks really nice. Now they are adding some oxygen into the water. So, that is the benefit from doing that.
And, sometimes folks will say, well, it's it's killing out the plants. It's not killing out the plants. All it's doing is pushing it off to the edges. So you don't have it right there where the where the water is falling down on the water and those waves are pushing it away. So that's that's the main benefit is it's adding that dissolved oxygen in there.
So, hopefully you don't have a fish kill when that plant material starts to die out. But, you know, I'm sorry folks, it does not kill any plants, it doesn't take away any plants or anything like that. And the other thing I will mention real quick is when you do have living vegetation in there, as long as that living vegetation is there, as long as it's photosynthesizing during the day, it is pumping water into that water into pumping air into that water. So, and what you'll see on a daily basis is you'll see the highest oxygen concentration is usually about midafternoon. Lowest levels will be about right before sunrise.
So if you go out on your pond and you go out right at sunrise, you see some big fish out there and they're gasping for air, that's a giveaway. You've got very low oxygen. Interesting.
Ken JohnsonSo when it comes to those aerators, should those be run during the winter? Typically, turn those off.
If there is, if we have a really cold long lasting winter and we have ice on the on the pond, There can be a winter fish kill because as that ice covers over the pond, obviously, there's not gonna be a lot of oxygen interaction between the atmosphere and the water, so that cuts down on the oxygen. If you add snow cover on top of that ice, even during the wintertime, there is some photosynthesis going on. So there's still some oxygen being pumped into that water. But if you put snow on top of the ice, that cuts down on any sunlight getting through there, and you could very easily have a fish kill during that scenario. And people won't know that there's a fish kill until they go out the next spring and try to throw a line in and they catch nothing.
Mhmm. So adding an aerator, it's it's kind of up to the individual if they want to do that. Most years, especially the the winters we've had for the last ten or fifteen years, we really haven't to contend too much with ice being on that on those ponds for long periods of time. So is it really absolutely unnecessary? I would say no. But if they wanna use it, it's not gonna hurt anything either. Your
Chris Enrothpond is well built. You know, if it's if it's deep enough, you probably wouldn't need something like that. Right?
Right. And DNR IDNR usually suggests that it'd be at least eight feet deep, to guard against any type of problems with the water getting too cold or that kind of thing.
¶ Can you prevent duckweed from returning to your pond year after year?
Ken JohnsonAlright. So we had another question come in, talking about duckweed. I personally kinda like duckweed. Don't know why I don't wanna get rid of it. But they're removing duckweed from their clam by a tractor bucket load. They're surrounded by prairie and timber. They wanna know why it keeps because duckweed keeps growing and how can they prevent it. Well, they
can they can control it. They're never gonna prevent it. Sorry to say. Duckweed can come in just like the name implies. They can get on burs and and other things, go from one pond to another and it'll come right back.
And one of the things that people may notice too, especially in the springtime, they might have a nice clean pond and then the next day they look at it and it's almost covered with it. And one of the things that happens with that is some of that duckweed at the end of the season will when it dies out, it sinks down to the bottom. And then once springtime comes along and the sun gets stronger and some of that sunlight hits the bottom of that pond, it starts photosynthesizing again. It becomes a buoyant, pops back up. So, that's one of those plants again that if you really wanna try to control it, there are several different types of of chemicals out there.
One type is a contact herbicide. So if you spray it, it just kills the stuff that it comes in contact with. Another kind, and I believe the active ingredient is called Floridone, it's more of one of those systemic herbicides where you put it in the water, you have to have a certain concentration of it to kill it out, and that will do a fairly decent job with it. But you'll also get sticker shock when you look at the price of it. It again depends, like you say, on how much you really want to put into that to get the result that you want.
So, you know, and again, that's that's really up to the individual on what they're wanting to do with that pond.
Chris EnrothAnd so again, like controlling duckweed timing wise, right now is probably too late.
Yep. Another one of those. And most areas when they're they're asking about that, they probably have a pond that's almost completely covered with it. So they did something to it all at once. With that systemic herbicide, yeah, they could very easily end up with a fish kill. Okay.
Chris EnrothYeah. So, yeah, definitely be careful with that. I've I've definitely seen instances where folks have pumped a lot of stuff into a pond and they've had the fish kill. Mhmm. The one actually right near my house. So they did that.
Hope you weren't downwind.
Chris EnrothI was not downwind. So but it it was a interesting situation because, you know, where the wind blows, that's where the fish wind up because that's where they all float above onto shore there. So
And that's that's got that's frustrating for the for the pond owner. And, you know, they've invested all that money in fish, and they probably have kids and or grandkids that wanna come out there and do that. So they have to wait a whole season or longer before they can get that fish population back. Yeah. So it's we usually anything after July 1, we say really back away from doing much with ponds except on the above ground growth after July 1. K.
¶ What about using vegetation to improve water quality for ponds?
Chris EnrothI've I've always mentioned to folks, you know, when we're talking about things like rain gardens, things like that, you know, if they wanna try to solve a drainage problem, you have to start higher up in the watershed, you know, and so I'm thinking, like, improving some of the drainage ways in the ponds or, you know, other things you can do. Does that ring true in that sense?
Oh, yeah. If you have the ability to do that, that's fantastic. I was just out on a pond a couple weeks ago, and they had a really nice vegetative area going back up quite a ways from where their pond was at. And their pond was very clean because of that, because it was trapping all that sediment before it got in there. And, of course, when you trap the sediment, you're also trapping some of those nutrients that are going in with that sediment.
So the more that you can have as a buffer between where the pond is and where the especially any fields are at or anything like that or nutrients are being loaded onto that, the better. Some people actually have a or a sediment ponds where the water will go in and settle and then you have cleaner water going on into the pond. The only thing is with those sediment ponds, you've got to clean those out about every two to three years.
Chris EnrothGotta have equipment access and everything.
Yeah. Yeah. Well, there's a
Chris Enrothlot of great information about aerators, duckweed, and vegetated buffers, for our drainage ways. I did not know that about aerators. You know? I'd always thought that aerators help to kill a lot of that algae that might be growing on the pond. I had not thought that it really just sort of pushes it to the side.
So very good information, for managing our ponds for this upcoming growing season. The Good Growing podcast is a production of University of Illinois Extension, edited this week by me, Chris Enroth. And a special thank you to our listeners for doing what you do best, and that is listening, or if you're watching us on YouTube watching. And as always, keep on growing.