Winter Rye and Sepp Holzer Raised Bed

I would like to install a couple raised beds next weekend and am wondering if I should try and plant a late fall cover crop to help prevent soil erosion over winter. The bed with be a Hugelkultur style bed. I am planning on it being about four feet tall. I also plan on heavy mulching the beds with straw. I am located near Madison Wisconsin which is in the south central part of the state. The zone I am in is 4b-5a. I was also wondering if anyone has ever tried to put rock in the actual berm itself. I am planning on planting Winter Rye as the cover crop. Any thoughts?

I think it's a great idea, for a few reasons.

You mentioned erosion, but I'd put that a couple places down on the list.

You'll want mulch eventually, so this is a great opportunity to grow mulch material on-site. I think the rye itself will grow OK with little or no mulch at the beginning. I understand hedge trimming equipment, if you have any, can be a convenient way to cut moderate-sized patches of cover crop, and that one can often get two or three cuttings over the course of a cold season.

A second reason would be to begin nurturing a community of soil microbes that are associated with healthy roots. Rye is good at this, and its roots also benefit the soil in a more mechanical way.

More subtly, perhaps less important than erosion, most people can learn a lot about a particular garden bed by observing how things grow in that exact place. Cover crops will get you an early start on understanding these new beds.

You might consider adding some fava beans and/or vetch to the mix, to start building up nitrogen in the soil.

I'm excited for you!

Stones can be useful for season extension; Sepp Holzer uses them to grow citrus in the Alps. I don't think they'd be very useful buried within the berm, but they're a common feature on the surface.

Thank you for the response! I am pretty excited about this opportunity as it will be my first permaculture project. I have been thinking about experimenting with some large rocks. Do you think it would aid the beds if I place large rocks at certain point of the berms. Like every 5-10 feet. These rocks will be exposed enough to capture some thermal heat. The rocks are roughly four feet high and three feet wide. Good idea?

Here is my paint drawing.

The scale is not definite or the amount of each pieces of the system. This is just the vision I had.