My house was built in 1952 and the basement was dug out from under the house at a later date. The way they did this left a perfectly sized (approximately 12"x40", about 4' from the floor) space with red clay, which I have 3 bags of good soil (50 quarts each) I plan to displace/augment that with. Presumably, there is no foundation beneath this column of clay - which is enclosed with mere cinder blocks - but I don't quite have a way of determining that definitively.

My question is: assuming I don't grow anything very tall - should I just dump the soil on top of the clay? or should I use the plastic from the bags of dirt (or something more durable) as a parchment? I don't plan on planting anything that would threaten cinder blocks, although I definitely plan to make a question about that, later (we're limited to cat-friendly plants, so).

Or, perhaps I'm a lunatic for wanting to plant in this space, and you good people would rather discourage me from doing so.

Any which way, I'm happy to hear any thoughts & opinions...

EDIT This is what the space looks like:


  • 1
    Why not using raised beds? Much easier for water handling.
    – Johannes_B
    Commented Apr 23, 2022 at 4:18
  • 1
    I would discourage you from putting dirt on your basement floor and watering it.
    – Johannes_B
    Commented Apr 23, 2022 at 4:19
  • It isn't the floor-! it's... an interesting sort of side space.... i'll attach a photo...
    – rm-vanda
    Commented Apr 23, 2022 at 4:26
  • 1
    What I'm seeing in your photo is what we in Wisconsin call a crawl space. Here, it's typically floored with a foot or more of gravel, but yours has a clay bottom, right? I'm assuming that there is a gap between the top of the inner cinder block wall and the top of the clay. Is that right, too? If so, how big is that gap?
    – Jurp
    Commented Apr 23, 2022 at 10:35
  • 3
    I would discourage the idea of growing plants which will cause an increase in moisture underneath a living area. Mold grows well in dark moist areas and could be a health hazard
    – kevinskio
    Commented Apr 24, 2022 at 11:48

1 Answer 1


I'd be quite concerned about water leaking from your plants into the surrounding area. I presume you are in a place with winter. You will be risking water-ice damage to various things behind the wall. Also, moisture is going to be a potential cause of mold and various related issues. Personally, I would not try to grow anything by just putting soil directly on any of the surfaces in the picture. Even with a water barrier, it could easily cause big moisture issues.

You might be OK if you use containers that are completely watertight, at least as "catch basins" under your plants. If you go that route, be very vigilant for condensation. Be very aware of the need for ventilation and temperature control. Various plants will respond very differently to this sort of situation.

One of the comments suggested tables for your plants. This is far better. You can get them to plant from all sides. You can see if you have water leaking and correct it immediately.

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