Quick question,

I have a 1/2 acre pond from 1-8’ deep. Upstate NY, where the ice is thick and the snow is deep. No aeration at this time.

I’ve read articles and blogs that suggest having ample rooted vegetation in the pond over the winter will help prevent winter kill of my fish. Other articles have said the opposite.

So, in your experience… which is it? Will rooted plants (pondweed, mostly) help prevent winter kills over a long, cold winter… or will it make the problem worse?

Thanks!!

Believe it or not, the answer is both "yes" and "no"!

Rooted plants will continue to make oxygen in your pond over the winter. This is even true in upstate NY for ponds under heavy ice cover.

Winter kill generally occurs when you have long periods of snow on top of your ice, due to complete blockage of the sparse sunlight.

Will you be able to aerate your pond? If not, can you sweep the ice if you get a heavy snowfall that does not blow off?

The way rooted plants can possibly make it worse is that when living things die off in a pond, the decay process actually consumes oxygen. If you have a pond with lots of dead leaves and muck on the bottom, that then suffers some vegetation die off, you will almost certainly then suffer a fish kill.

However, I think the rooted plants are almost certainly a huge net plus. I am not an expert and live in warmer climes. Hopefully, one of our experts that lives in the North can chime in with some better information.

Rooted plants will help BUT 1) They need to get sunlight so they can at least partially stay alive. They usually won't grow because of the cold water. 2) They need to be the type that doesn't die back during the winter.

If there is a lot of plants in there that die off, it can actually hurt the pond because the dead plants will start to decay and the microbes and bacteria will need O2 to keep that decay process going, O2 that the fish need.

That makes sense, thanks guys.

Unfortunately, shoveling the pond after heavy snows isn't really something I can do. Sounds like maybe I should look into aeration over the winter months. Seems like that the's "right" answer.

Can't wait for the ice to come off the pond so I can see whether or not my fished lived through the winter! We're close, maybe just a couple more weeks.

Thanks again.

I think that aeration is probably your best solution, since that may be an even more important factor for your pond's health during the summer!



P.S. I have lots of friends that grew up in the frozen north. Several were big on recreational ice skating with family OR trash can hockey with their buddies. I know they had some efficient methods of sweeping snow off their ponds for skating. I don't believe they had to do it TOO often during the winter?

Google "Lake Effect Snow". Sweeping won't touch it.

I have relatives in Orchard Park, just up the hill southeast of Buffalo.

We have pictures of snow drifts partially covering the windows of their house ... on the 2nd floor!

Pond depth and water clarity also play a big rolls as to how quickly the rooted plants become a problem under ice and snow cover. Water clarity at freeze up determines how much light can enter ice or open water from an aerator. Water clarity affects how deep the plants will grow in the pond. The deeper the plant growth the faster that oxygen will be consumed in the darkness of snow cover because more plant mass to decay is present. The deeper the pond the more dissolved oxygen(DO) that will be in the pond before all DO is consumed.

Generally during winter it is the phytoplankton not rooted plants that provide DO to the pond if the microscopic phytoplankton receives sunlight. However in ponds with more rooted plants the fewer numbers of phytoplankton. The two types of plants compete with each other. Rooted plants have been shown to chemically suppress growth of phytoplankton. There are winter phytoplankton species that thrive in cold water. A pond only 8 ft deep is a lot more prone to winter kill compared to a pond 16-24ft deep. Larger volumes hold more DO for longer periods. The amount of organic decomposition starting at the bottom is where DO is lost first during winter.

Wow, thanks for all of that great info!



For a remote pond (without aeration) does anyone fertilize to enhance phytoplankton growth just prior to ice cover?

I could see how that could provide some extra oxygen to help the fish over-winter in a shallow pond.

I could also see how that could be a disaster, where your bloom only makes it through half of the winter, and then you have MORE decaying plant matter in your pond consuming valuable oxygen.

Fertilizing prior to having a ice snow covered pond is a formula for a fish kill. Too much of any plant growth under ice and snow is not good and very risky.

That is what I thought, but wanted to make sure!

Thanks for coming back to clarify the dangers in some of my hare-brained schemes.

(If Wiley Coyote had access to Pond Boss, he would probably be eating a roadrunner sammich!)

Yeah Bill… this makes me very nervous. We had a pretty mild autumn, and the plants were growing like crazy when winter hit. Then the pond iced over quick and has been submerged since. It continues to snow, even as I type this.

I guess at this point I just keep waiting to see.

Ps. FishinRod, I have a fountain that aerates well during the summer, so the winter is the only concern.