Pond Boss Forums POND CONSTRUCTION Creating habitat Brush PIle for Pond

first off I hope everyone had a nice and safe Thanksgiving. I just had a Elm tree in my yard trimmed. I have several logs and lots of branches to make brush piles. Are elm trees safe to use? Do they have any of the tannins as walnut and oak?

Hey 2blade,

Elm is scarce in my area after the Dutch Elm disease came thru several years back so I can't provide any personal experience. If no one replies, when in doubt let it cure well before putting it in the pond. You can also do the DD1 bucket test which is put a couple of small pieces of the elm in a five gallon bucket of pond water. Let it soak for awhile then add a couple of fingerlings or minnows to see if they survive.

Good Luck,

Bill D.

Has anyone actually had a fish kill after adding a brush pile to a pond that is over 1/4 acre? I ask because I have just added brush piles without giving it a second thought. Seems like any mildly toxic material would seep out slowly and get diluted and degraded. Anyone with actual experience with this out there?

Yep, I put a bunch of fresh dozed oak in my new pond. I stocked, everything died; treated with pool chlorine with no effect. Waited, stocked again and the results were the same. Finally pumped the whole thing out and let our plentiful summer sun finish it off.

If there were no fish in the pond before adding the trees, how did you determine that the trees caused the fish kill? Seems like any number of things could have made a new pond unsuitable for fish.

The water turned black about a week after the first rains. Nothing else could have done it. I had it tested and they confirmed tanins. It's lethal stuff.

Must have been a lot of wood for the amount of water, or you have some mean trees. I have seen the water in vernal pools turn black before from fall leaves, but not a good size pond.

Yeah, this was when it was built. I had the oak trees put into the bottom of the bowl as structure. Then it rained. After 4 or 5 days, the water turned black. It stayed that way until I pumped it dry.

Elms are ok - have used them plenty of times. Just don't load the whole pond up with them. Dave and I have had opposite results with oaks. I have used them plenty with no problems. I do not however load up on oaks and often have added lime. I would be careful however.

Eric, do you use fresh cut oaks?

Yes but the size (volume)is small compared to the amount of water. I would be much more cautious if you were talking about 3 or more piles of fresh cut in a small pond. To much risk for me to try that. During Katrina a bunch of big oaks (20+ inch diameter trunks) , with leaves , fell in the water. Could not be removed - to big. I added a bunch of lime to counteract the tannins.