Just finished ( I know, I  know, I am a bit late, but illness is kicking my ass) my 50'x15' raised vegetable and it is time for fill the sucker.

It does have some soil in it but not of good quality, kind of sandy.  Plans are to push that soil off to the sides.  

Recently had a tree cut down and kept the larger stumps with plans of adding then the garden as filler and as a quasi-barrier between grows.

Guess they could be used as a walk way too?

I have seen other filler their raised beds with logs and such on the very bottom and then the good soil on top, but this is a bit different.

Your thoughts?

There's a term for it: hugelkultur.

You're not going to get much from bad soil unless you plant something that can tolerate bad soil. It's better to use good soil instead though.

Sandy is good in a garden. It keeps compaction down.

Stumps are fine as filler but be aware that they will consume nitrogen from your soil as they decompose so you will likely have to add nitrogen.

Yeah, I know.  That is why I and pushing this soil off to the perimeter of the garden.



Adding nitrogen does not seem like that big of an issue.  

It's not, but you might check and see if you have a local Extension office that does soil testing.  Get a test after everything's set up just before you plant, so you'll know if you need soil amendments right off the bat.  Maybe another one mid-season so you know how the decomposing stumps are affecting the nutrient levels.  Too much nitrogen is almost as bad as not enough.

What kind of wood?  That will affect the decomposition rate; oak will probably break down in a single season if buried and kept moist, Osage Orange will still be there when your grandkids decide to bury Rover in grandad's old garden.  And then there are some like walnut, which generate substances toxic to other plants because it would just as soon not have them competing for resources (Google 'allelopathy').

Thanks for your input.

Copy on the testing and the stumps are from a red oak.

Those oughta break down just fine, and add some nice organic matter to the soil for next year.

Collect as many of the falling leaves as you can this fall put them on top of your soil to keep weeds down until spring when you can Roto-till them into the soil along with other things like coffee grounds to help out your soil.

I always thought the purpose of doing raised beds was to corral good soil in a area so plants could enjoy the benefits of the good soil . why would you intend to put crummy stuff under the soil? Yeah I get you are hoping the stumps will rot down and add organic material to your bed but how exactly do you mix it all together so the plants can get at it?

If you shove it deep enough or to the sides enough so the current plants don't come in conflict while it is rotting down it is going to be a lot of work down the line to mix it in when it does finally break down.

Best to create a pile somewhere where you can track the breakdown and work the material then add it to the beds when it is useable.

When I take the time to build a bed my goal is to prepare and use good soil right away , sticking lots of stumps and such in there now may give you something good down the line but also forces you to deal with less than great conditions for the time it takes all the junk to break down.

Why not just fill it with dirt?  If you have to do wood do wood chips in the bottom.  Good for drainage.

Theres a permaculture technique called hugelkultur.  This has successfully been applied to raised beds and is extremely effective.  Basically, you throw your wood down, then fill the red of the bed with good soil.  Through winter/spring the wood gets totally saturated with water and acts as a sponge.  Throw your plants in come spring and once they start reaching roots down past the first several inches(I've had particularly good luck with squash and tomatoes in this type of bed) they can wrap them around the wood and absorb the water the wood has absorbed.  I went 6 weeks in late spring one year without watering my tomatoes (under a plastic tent) and they were doing just fine.



When I build a new raised bed it always takes a few years to settle out anyway, so fill the bottom with wood, then top with as much compost/topsoil you can, then next year top the bed up.  Works great.