Plants growing through liner.

[Event Horizon]

I thought I would start a thread on a topic that keeps nagging at me ever since someone put this in my head. Has anyone ever heard of plants growing right through the pond liner? I have heard people say that if you don’t rotate your bull rushes once and a while they are so invasive the roots can grow through the liner? I have always found this hard to believe, but do rotate them a couple of times each season to be safe. I also keep the pot on a piece of flagstone, so I don’t really have to worry about them. The way I see it is that a root will take the path of least resistance so why or how could it just pop through the liner? We do however have some other plants that are not potted. If you look at the pictures you will see a plant on the small ledge by the patio that is bog bean. It just grows and you can cut it and place it wherever. You will also notice we have some large ledge rock acting as a border between the patio stone and the pond. The liner goes under the ledge rock and up behind to where it meets the patio stone. Yes the moss loves it there as it gets constant water from wicking. I have noticed that some of these roots will grow under the ledge rock as there would be some yummy nutrients under it. Does anyone see anything wrong with this? Is there a risk of a root getting so big it will go through the liner? When I pull some of the plant out the roots seem much smaller and finer than the roots you can see in the water. That is exactly what I would expect, (path of least resistance would state it is easier to branch out and stay thin rather than fight a heavy rock). On the opposite side of the pond we have a bunch of grasses growing loose but I have a extra layer of pond liner and filter cloth under it all.

 

[sissy]

At the other house I own I had to pull the liner on one side and make the pond smaller as large roots were pushing on the liner and you could really see how they were bulging the liner .We also had to take large cattails out that were hard to get out as they were stuck to the liner .Could not see any damage to the liner but only would have been a matter of time .The house was empty and pond was neglected for at least 4 or 5 years and pond was spring fed .It was nasty and over grown and at least 20 inches of sludge on the bottom .A few fish but not many .Took 3 weeks just to get the back fill in there and get the pond stabilized and several storms also did not help .Root trimmed all the plants around the pond that were nice plants and took out the weeds and trimmed the tops of the shrubs .Trimming will put more energy in the top growth and less energy for root growth .

 

[capewind]

Sissy, while a bulge isnt a tear, I am curious as to what type of liner you have? Rubber will stretch too, so wondering about the risk factors, per mil in size. I am a member of the path of least resistance camp too, so wondering if it would take a "root bound situation" to cause much of a risk. Leave something in too small of a pot, and over time, a plant can bust the pot, so thinking extremely root bound in a pond, could in theory bust a liner over time... Sounds like the practical answer here would be occasional thinning, just like a land bed or pot???

 

[sissy]

The liner was put in around 2004 neighbors told me and was 45 mil thick by what I could feel .I don't live at that house .I could see the liner had really stretched out bad though .I could even see how stretched out it was when we pulled that side up .Even after we put it back and laid dirt behind it and refilled it you could see the bulge .After the water went in it sorta settled back but now you look you can see the bulge sorta goes out now instead of in .It is ok and not leaking .

 

[addy1]

I have some plants that have sent their roots, up and under rocks around the pond. The roots just keep going where there is a gap to grow into, even up and out of the water. They have never tried to go into the liner. I use bend tarp and liner ppl36

The land plants, near the pond and stream, just sent their roots up and over the liner, none have tried to come into the pond, through the liner. Even in Arizona, where I had a mesquite within 4 feet of the pond, the trees roots grew to the liner then up and over into the pond. None, in 10yrs or so, pushed through the liner. They just did the seek for water travel, easiest route.

 

[Event Horizon]

I know the day will come I will have some bulging due to the fact I have gone so close to the trees, but that does not worry me. I was very careful to leave the liner as loose as possible during installation. I have plants growing in from all sides and it was really the ledge rock that kept me wondering. I have had potted plants that have burst from being root bound but again, the path of least resistance will do that. I think you guys are right and just trim it back once and a while. I can easily just pull it out (or cut it) from under the ledge rock, and just sit it down again. When I first put it in I just plunked it down and put a small piece of flagstone on it. When I heard this story of plants going through the liner I was told specifically watch out for the bulrushes. Up here in Canada anyway they are very invasive. Mine are really not that invasive, that is probably due to the placement in the pond. I have them down at the far end which does not get too much sun.

 

[capewind]

I, against hubby's wishes (he is a professional landscaper) insisted on planting some dwarf trees wayyyy too close to the house and pond, and hubby told me that I was signing death warrants on the trees (he wasnt worried about the liner), but said I can have my way for the next 12-15 years anyways

Take a look at what I made him do with these two thread leaf maples... They should have a MINIMUM of 3' in all directions from the stalk for growth... Both will require pruning and training for the above ground growth, and that wont present an issue, but someday, he will either have to shut the ponds down to dig them out, or chop them down... The green one to the left will have a better life, than the red one to the right... it is only 18" off the foundation, and 12" from the patio, with a waterfall built right up to it...

 

[HARO]

Welcome to the forum, EH. (Now THAT really sounds Canadian, doesn't it?) I'm just down the road from you, and work part-time in a garden centre, doing their water-garden area. I've heard several stories of cat-tails (they are NOT bull-rushes) growing through liners, but never a first-hand account. It's always the next-door neighbour's brother-in-law, the distant relative of a former friend, that kind of thing. However, I have personally seen cat-tails growing through the pavement at the edges of parking lots, so I wouldn't underestimate their strength. If you were to plant them between a LARGE rock and the liner, they could conceivably push through a 45 mil. liner. I have always planted them in a large tub or pan (no holes) and placed the rim about an inch below water level. Any roots that come over the rim are easily pruned.
John

 

[Event Horizon]

I, against hubby's wishes (he is a professional landscaper) insisted on planting some dwarf trees wayyyy too close to the house and pond, and hubby told me that I was signing death warrants on the trees (he wasnt worried about the liner), but said I can have my way for the next 12-15 years anyways

I agree you have a good long while before you need to worry. These pictures were taken of my first pond 9 years ago. It is my understanding the trees are well over 25 foot and the pond is still running. I would have to think some of these roots hit the liner and again (path of least resistance redirected). With that said over 10 years if the roots hit the liner and went around they must have gotten fatter and started to bulge the liner.

 

[Event Horizon]

Welcome to the forum, EH. (Now THAT really sounds Canadian, doesn't it?) I'm just down the road from you, and work part-time in a garden centre, doing their water-garden area. I've heard several stories of cat-tails (they are NOT bull-rushes) growing through liners, but never a first-hand account. It's always the next-door neighbour's brother-in-law, the distant relative of a former friend, that kind of thing. However, I have personally seen cat-tails growing through the pavement at the edges of parking lots, so I wouldn't underestimate their strength. If you were to plant them between a LARGE rock and the liner, they could conceivably push through a 45 mil. liner. I have always planted them in a large tub or pan (no holes) and placed the rim about an inch below water level. Any roots that come over the rim are easily pruned.
John

Hi John, I really should have known they are cat-tails. I have mine in open baskets and the roots do grow out the bottom. As I mentioned earlier I keep them on a piece of flagstone because the stories I heard about going through the liner were in regard to these guys. Mine really do not do that well. I used a decent soil but put a larger stone on the top rather than pea gravel. My thinking was that they would be so invasive it might slow them down. From the attached picture you can see they are just kinda there. I do have them on the south end of the pond under a fair amount of cover from large trees. The pots are a bit deep as well. I would say the top of the pot is about 3’’ below the surface. Maybe this will be the year to dig them up, change the pots and move them into more sun. Regardless I might be doomed as it seems they get to a decent height and the red wing blackbirds are venturing into the pond with the babies for the first time. It is rather comical to watch these young birds coming in for a bath for the first few times. They end up landing on the cat-tails and knock them all over and make a mess of them anyway. lol

John.

 

[DrCase]

Welcome to the Forum
I would think a root in the pond would have a real hard time poking through a 45 mil liner
I have seen nut grass poke up and through a above ground pool liner from underneath

 

[Mucky_Waters]

I've also been curious as to whether roots can grow though a liner. Actually I'm sure they could, but the question is would they. As already pointed out they can grow through pavement and cement if the want to, but usually when they grow through those things it's because the little micro roots or shoots find tiny little hairline cracks and once they get in there they wedge it open. But if that hairline crack isn't there to begin with, it seems they can't get started. Perhaps an old weathered liner that was starting to develop cracks in it might be enough for the roots to get a foothold and work their way deeper until the split the crack open.
Anyway, what I've done for a little extra insurance is put another layer of scrap liner over the areas where I put rocks and planned to have plants growing barefoot.

Nice looking pond BTW.

 

[Mucky_Waters]

Welcome to the Forum
I would think a root in the pond would have a real hard time poking through a 45 mil liner
I have seen nut grass poke up and through a above ground pool liner from underneath

I read you post and was curious, did this nut grass come up directly through the liner, or did it poke through a seam?

 

[DrCase]

I read you post and was curious, did this nut grass come up directly through the liner, or did it poke through a seam?

It was a thin swimming pool liner i saw it come through , it came up were ever it wanted
Digging down 4" would have saved the pool

 

[capewind]

I could be wrong but thought the basic pool liners were only 15 ml? A poor analogy at best, but at one point in time folks used plastic garbage bags as weed barriers, and after awhile (few years or so). things did tear them... what is the thickness of garbage bags? 2-3 ml at best? So I guess thickness verses the persistance of a plant species, and back to the path of least resistence... if there is an easy path, the roots will likely go that way... if there isnt, well, back to root bound plants busting pots, or in this case, through a liner?