Building an 'insulation garden' over the top of septic pipe

Day 1 moving into the new homestead, we had a frozen septic pipe and water back up into the basement.  Yay, welcome home!

I wish to try to prevent this from happening again.  I built a raised bed garden over the top of it last fall with the hopes of adding some insulation.  I planned to put in currants, gooseberries, and other shallow rooted plants into the garden.

It is early spring in Wisconsin, and nearly time to plant the currants.  While the initial intent to insulate the pipe is, I think, a good idea...wondering if adding rooted plants of any kind is a bad idea.  Even if the plants are known to be "shallow rooted," could they still find their way down to the pipe and cause more problems?

For context I've added a few photos of the area.  The pipe garden is on the north side of the house.  Thinking the currants should do fine in part shade.  Guessing the pipe is 6ft or so under the ground.

Should the pipe garden stay or go?!  Currants and gooseberries okay?!

I would add soil for insulation….probably more than you have.   But then, I am a great one for overkill.   I would stay away from roots as much as I could.  This goes with the overkill … why take the chance?

I agree with John.

There are several posts here on the forum where folks have problems with roots growing into the septic lines.

I would not want to take chance on even shallow roots plants because roots like to reach for water.

Something like sedum, moss rose or portulaca might not be a problem and would offer some flowers for butterflies.

The more soil that is added above the septic lines the less chance of freezing.

Thanks for the feedback Anne and John.  Gave it some thought, and wondering if I might change the garden to something like DirtPatchHeaven's raised bed pallet gardens (image below).  Here is a link to her plans - https://www.etsy.com/listing/958618806/pallet-raised-garden-bed-principles

That would add more soil & insulation, and also more distance between roots and drain pipe.  And I could use shallow rooted annual plants versus the perennials that was my original idea.  Any additional thoughts?

Thanks again!

Over the years there has been a lot of discussion of raising foods to eat over septic lines.

I would say that is a personal choice.

Here are some threads that might be informative for you or others:

https://permies.com/t/135173/veggies-proximity-septic

Tyler said, "Personally I would grow compost crops over the septic field and grow my vegetables elsewhere, if possible. But this would mostly be to avoid disturbing the lines, which are shallow.  I think the only likely source of contamination would be root crops if you choose to grow vegetables over the lines.  

https://permies.com/t/62163/growing-pressure-dose-septic-system

Just a thought. Active soil melts soil earlier warms the earth.

Back to Eden wood chips garden.
Wood chip piles
Wood chip mulch
Old hay bay mulch bales less than $20 aim for free.
Grazing the land.
Hot chicken manure and hay... Wood chips.
Sheep
Etc.

Just 8-12" of Wood chips in Sep-Nov would do...  I'd do 3'

10' past septic all around. Scrape off April and put around anything... or keep adding for years.

After
Quick seed grass.
Throw annual flower bed in.