Pond Boss Forums POND CONSTRUCTION Soil questions Mucky clay on pond bottom

My pond is now about half a year old and is a little over an acre and a half. The soil was high in clay content. The dam has a compacted core that went down over 12 feet below the stream bottom we dammed up. The pond bowl was shaped and marginally compacted just by the nature of driving around on it with the dozers and trackhoe. Areas of soil ended up fairly loose, especially in the back which I assume is helpful for all the emergent plants I'm starting in the back. I was planting some spatterdock and waded in and would sink into the clay/silt in some places almost up to a foot. It wasn't this soft before it filled up. My goal is to get the back filled in with spatterdock, lily, iris, various sedges, rushes, swamp milkweek, pickler weed, etc for looks and habitat. The whole pond gets fairly muddy after heavy rains but I figure that will quit once I get some real good vegetation going. It clears back after a couple weeks back to green.

Can I expect the soil to stay this loose or will it settle down over time and compact a little so it's easier to walk on? My dog who was formerly terrified of water has now become quite the water bug and loves to run around in about a foot of water stirring up the clay on the bottom. Will this end up getting covered in algae or anything that will limit how much clay she stirs up or is there anything else I can do? I have grass coming up around the pond perimeter.

Interplexr, I am afraid the soils there will always be soft, but should settle a little over time since they were never originally compacted. In time, much of the loosest soils will migrate to the deepest parts of the pond as fish move them around plus from wind/wave action.

As for planting spatterdock, are you aware it is a fast spreading, highly invasive plant? It can take over an entire pond in a single season.

I understood it to be similar to water lilies and that it can only go so deep. My goals are to have the back end filled with plants but as the pond gets deep it can't spread. I figured I'd be having to work to keep that and lilies in check though. I was thinking pulling them as they started moving where I didn't want. Hopefully it won't be unmanageable.

It provides a lot of benefits in a pond for habitat. Depth it will grow in depends mainly on water clarity. Once established and rooted, it can become very expensive to control, even more expensive to eradicate. The speed with which it can overtake a pond's shoreline and shallows can be mind boggling.

"Pulling" can spread it, as it grows from roots, rhizomes, seeds, and possibly fragmentation from cuttings. There is no known biological control and Spatterdock can be cut and the rhizomes can be dug up but physical control is difficult to impossible because it can reestablish from seeds or remaining rhizomes.

Is water lily as bad?

Some lily species are very invasive, some are not. Most Winter hardy lotus are great. Hopefully Bill Cody will chime in on this. Bill knows his lily and lotus!

Spadderdock can initially appear as a good plant. Once it becomes well established with rhizomes 3"-4" diameter and 8'-10 ft long and growing into 10ft of water you will only control them with chemicals. No pulling and digging will ever get them under control. I would also stay away from lotus - all types. They are also fast spreaders in soft soils.

For hardy hybrid lilies look into the small and medium spreading types for slower growers and use the large spread varieties that will spread out quicker and grow deeper 6-8ft. Very few of the hardy hybrids will spread anywhere near as fast as spadderdock or wild white water lilies. You will be much happier with hardy lilies compared to spadderdock. They cost a little more but the long term benefit and lack of headaches long term make them well worth the money. I've fought with spadderdock, wild white water lily and lotus - never again.

For hybrids look into pink & white sensation, red paradise, red sensation, Attraction, Peter slocum (big pink), unnamed pink is economical, Colorado, Sulphurea (yellow), Charlene Strawn (Y). Some of the large spread hardy hybrid yellows & whites can grow into 7 to 8ft of water. All can easily be controlled with glyphosate based aquatic herbicides. Perry's Water Gardens in N.Carolina have very good quality and a large selection of hardy hybrid water lilies. I got almost all my 15 varieties lilies from them. Also shop at http://texaswaterlilies.com/