Todd:

I'd sure use pondweed if I had it. Sounds like an ideal mulch. Shouldn't carry in any weed seeds that would like the orchard environment.

The Fruitnut

fruitnut:

Thanks for the input. Next summer my brother and I intend on removing a lot of pondweeds from a pond at our parent's farm. The Nebraska Game and Parks Commission employee I talked to earlier this year recommended physical removal instead of chemical herbecides to control pondweeds because removing the weeds is also removing some of the nutrients that cause excessive pond vegetation. Also, herbecides for pondweeds are very expensive. I am glad to hear something positive about this idea. Has anyone out there used pondweeds in their orchard or garden?

toddfiala

Never tried this but I have mulched with a lot of different materials and really everything I've tried works as long as you keep a couple things in mind.
If you are applying the material directly into the orchard don't pile it to high. One foot thick will work but much more and you could have problems with it.
Since this material will be very wet, it may tend to rot Anaerobicly. That means it will stink like a septic tank and draw bugs and generally be offensive. I would not think that would be good for your orchard. So, be sure to spread it out enough that it can dry out. Depending on your climate, you may want to choose a day when you will have 3 or more days without rain and the ground is not to wet.
The more you can chop up the material so that leaf and stem surfaces are broken, the better the material will decompose into nice compost.
All mulch needs to be balanced for it's nitrogen uptake and release. Generally green material will have plenty of nitrogen, while roots, woody, or brown materials will consume nitrogen for a while as they decompose. They will release it later but nitrogen could get in short supply for a while. My guess is that there will not be enough green in pond weeds, so you may want to add a little bird manure with it (chicken, turkey or such). For example, tender green grass trimmings or very leafy green alfalfa have sufficient nitrogen. Grass hay does not have enough and straw has almost none, so they will steal nitrogen while trying to break down. Roots and steams also have almost none.
In particular with pond weeds, I'm not sure what pond soil will do, but generally soil in the mulch does not work well, as it provides a place for weeds to grow, when what you want is for the mulch to inhibit weeds. Weeds growing up in your mulch can be very problematic since you will have trouble mowing over it (to rough and to high and too thick) and other machinery will have trouble dealing with it.
Again, I have not worked with pond weed in particular, but these are things I have learned for working with a wide variety of mulch and compost materials. I hope that helps.

softmentor:

Thanks for the input.

I would think that pond weeds would be far more green than anything that grows on land. The brown components of land plants are all carbon in the form of structural fiber and lignin, since water plants are supported by the water they do not need to put as much energy in to supporting themselves with carbon and instead channel that energy in to building proteins and chlorophyll to continue the incredibly rapid growth rates of the pond plants.
Also, keep in mind that the primary benefit of sea weed is the high and diverse mineral content, this is because the ocean never suffers mineral deficiencies so the plants growing in it have adapted to make the most use of what they have available, the pond suffers the same mineral shortages as the soil that drains in to it and as a result freshwater plants do not soak up as many minerals and will not have as many to release in to your soil.

I did this once. I took a bunch of milfoil looking stuff and brought a bunch home to drop on the garden. It smelled pretty funky for a while. Lots of little aquatic animals also made the journey. It broke down pretty fast, if i remember correctly (this was last summer).

I drive by the UofM aboratum every day here in minn. where they do all the research for fruit orchards. And they use large amounts of pond weed, mostly milfoil, they dump it then spread it out after a couple of months. I dont know if there doing a study on it or not but they have been doing it for several years.