Pond Boss Forums AQUATIC VEGETATION Balance of plants in the environment Shoreline plants now submerged. Will they die?

New pond continues to fill with water. In early spring, we had a 6-week dry spell where the pond level remained pretty constant. Many shoreline grasses/plants grew up strong around the perimeter in the spoils. I don't know exactly the species of the plants and how water-tolerant they are.

After a very wet summer, the pond level is up another 18 inches or so. Much of the grass is now partially to fully submerged.

If this trend continues, will the grasses perpetually in the water eventually die off? I hope some do, in order the open up the shoreline.

I think it depends on what type of plants they are and how much the water level fluctuates.

Knobber, do you know how deep the unwanted plants are? I raise and drop a small pond of mine, and grasses sometimes die, but the stalk remains. I would think they'll drown out, but like Sunil said, it depends.

Most perennial grasses will begin to die off after being submerged in water for a few days. A few species of true terrestrial grasses can survive a fair bit longer.

Of course there are lots of other plants out there, including shore line plants that can handle fluctuating water levels and long periods of immersion.

Hopefully, most of that stuff that is bothering you will be dead within two weeks?



P.S. I like the pond and how green your property is currently. The reflection of your red shed in the pond water is also a nice touch!

Hey, thanks! The grass around the pond and up the hill was just planted 2 weeks ago. The barn reflection in the photo was just by chance!

I will try to ID the grasses and check depths a little more carefully.

The predominant plant looks to be rice cutgrass, which prefers wet, fertile, silty, soil. It gets aggressive in disturbed wetlands, which my renovated pond is.



They are growing anywhere from 0 to 30 inches of water. Too early to tell on this new pond how much the water level will fluctuate.

I think this grass is here to stay. It is just a matter of the depth of water in which it can tolerate.

I have rice cutgrass growing in over 3' of water, and happy there. It looks to me that you may also have cattails which can spread quickly by rhizomes and completely cover your shoreline if you let them. Looks nice, good luck.

Knobber,

I can't remember - what fish are currently in the pond?

If you have undesirable plants that are going to flourish under the existing conditions, then the best time to address the problem is yesterday!

Such plants are only going to drop more seeds, spread more runners, establish better root systems, etc. in your pond.

I would accelerate your plan to identify which plants are growing in that invasive strip. Once you identify most of them, I would then start a new thread in the "Controlling unwanted plants" sub-forum.

There are several pond management experts that typically reply in those threads. They can tell you exactly the right herbicide to target your plants. Specific targeting is the most important thing IMO for wiping out invasive plants.

If you have plenty of water available for your pond, then you could even drain it 1-2 feet so those plants are completely exposed. Then treat heavy with your herbicide while getting very little directly into the pond water. Wait a few days for the herbicide that landed on soil to degrade, and then re-flood your pond.

(That should preserve your existing fish. However, you should probably list all of the existing aquatic life in your pond when you open your new thread.)

Gotcha. Rod beat me to it. Really nice looking property.

Good to know. Thanks, Ro40. Yes, cattails are mixed in as well. Also some bulrush and Bur Marigold, but I like those plants! I planted two patches of pickerelweed, so I want to avoid killing them.

Thanks 'Rod.

Only FHM are currently in the pond. I want to add RBT in the next few weeks.

I have been doing a lot of reading/shopping. I am pretty sure that a glyphosate is needed on those emergent plants like cutgrass and cattails. Something like Aquaneat. I live close to the PondGuy/Airmax headquarters, and they have glyphosate product called "Shoreline Defense."

I use CattPlex with a surfacant, safe for fish and keeps cat tails out of my ponds fine. Have used it for years and have been very pleased with it. Cat tails go yellow a few days after spraying and die clear into root system.

When killing cattails, it's best to spray them in the Fall. Don't forget to remove the catkins before they blow apart and scatter new seeds all over your pond. Cut them off, shove them in a plastic bag and put them in the trash. I collect them in a 5 gal bucket as I cut them off the plants, then dump that bucket into a heavy duty garbage bag.

Catplex is just a 53% glyphosate, so any other pond rated glyphosate will do just as well.

One question is, is this the full level of the pond? or will it fill up more, that will submerge them even more? which will make a difference in their survival chances.

I have some shallows that look very similar to yours. I've been surprised at how long the submerged veg has stayed alive. It's been flooded for several weeks now and some of it's still green. Glad it didn't all die at once and flood the pond with dead vegetation.

Good question. This is a new pond, dug last December, still filling up. Finish grading and grass planting was just completed. So, there is no history, yet. The high water mark was planned to be another two feet or so from the current level in the picture.

Do you generally rake out the dead plants after applying glyphosate? For my pond situation, raking would be a lot of work for me. Ugh.

CattPlex is almost double the price (on Amazon, no less) of Shoreline Defense that I mentioned. I haven't checked the label details, but are some glyphosate products better than others?

I don't bother raking it out.

Follow up. The cutgrass became submerged and died off over the winter. I cut and raked a ton of it out of the pond and burned it.

I installed a drainage pipe this spring, so the water is now at a constant level and not rising any further.

The cutgrass is back, thick as before in some spots, but thinner in others.

I did a test with a 3% solution of Airmax Shoreline Defense (53% glyphosate) as recommended on the product page. It seemed to be effective.

After reading the label more closely, it seems 3/4% to 1% solution is the recommended amount for cutgrass and cattails. I will give that a go.

Don't forget to add a surfactant. I use Cygnet Plus. 1 fl. oz. per gallon of tank mix.

Yes. I have Alligare 90. I use 1 oz per gallon for above water aquatic application.

I like the new pic of your pond.

Is that the new drainage pipe in the background?

Now that you have your water level at its "normal pool elevation", you can start creating the shoreline look and habitat that you desire.

Keep eliminating your invasive/undesirables.

You said you previously planted some pickerelweed. Keep planting more things you do like. Invasives have a much easier time colonizing into "open ground".

Have you looked at any of the shore iris plants, or very slow-spreading lily pads? Might be some good plantings available for your area that your wife can also see from the house and score you some additional "good husband" points!

Thanks! Yep, that is the new overflow pipe. It drains into a swale and low area which was the original runoff route before the pond was renovated. Yes, the waterline is now stable. Now I can build a dock in addition to creating the shoreline.

There are cattails mixed in that grass, and I think I should eliminate most (all?) of them before they get out of control. I plan on more pickerelweed planting. I also planted some spike rush, but not sure if it made it. I have blue flag iris in a small garden pond that I can transfer to the big pond.

Any screen across the culvert to keep your fish from going downstream?

I have seen a guy with a similar set up, make a "V" in front of the culvert. Upper 2' was boards, lower 2' was weld wire, so the floating debris would get diverted and not tend to block the screen.

I think he took it out in the fall so the leaves would go through the culvert during gentle fall rains.

I would.