If the bottom is not open to the ground they are containers and should not contain garden soil. For long term plantings they would do best with the gritty mix. Make sure the containers have drains. With concrete bottoms I would prefer the drains to be out the sides at the bottom. Calistoga Al

What if the containers are bottomless?

If the containers are bottomless and in contact with the ground, then they are raised beds and should be treated as such. That means you want soil in there not a soilless container medium.

Thank you very much for your response.

Is there a limit on how tall the wall can be on a raised bed before it has to be approached in a way different from a raised bed? I have a friend that is planting inside a very tall shopping crate with an open bottkm that is in contact with the soil. It is very tall but I suppose that regardless of this, it's still a raised bed....albeit a very high one.

Also how much contact must there be before it's no longer a container but a raised bed? I've seen people put basic black nursery pot containers over existing dirt or soil so that there is a connection but it's a meager one because of how small the drainage holes are. It's not a completely open bottom like you would expect on a real raised bed but it still does touch...the soil inside the container/pot with the soil below....barely. Would this method still be a raised bed but with lesser drainage consideration?

Thanks

An ordinary nursery pot set on the ground would usually over time, depending what is in the pot, have the roots grow into the ground. Depending on the plant it would be expected over time to break most plastic pots and in fact be a garden plant, neither container nor raised bed. Calistoga Al

Any container with a solid bottom - drainage holes or not - is still a container regardless if it comes in direct contact with garden soil or not.

While it is technically correct that a container is always a container, if it is buried, it will behave differently than if it is sitting on top of the ground. If you have a container filled with soilless medium, then it will perform like a container regardless. There will be some wicking if it is buried, but you'll also have interface problems so it's probably best to consider it a container. However, if you fill it with field soil and bury it so that the soil it continuous through the drain holes, it will behave like a raised bed.

A 'barely' connection is just that, barely connected and as such wicking will be less effective. You really want to bury the pots at least a couple of inches and then mud them in really well to insure that the connection is solid

Thank you for l the responses. I did a little experiment yesterday and took a container with small holes in the bottom of it that was filled with garden soil. I then watered it and put it on a dirt mound and ensured that there was a connection. Hours later I came back and you are right. The top of the dirt mound was soaked. It wasn't buried but just sitting on top.

No matter what you call a pot resting on the ground, if there is a pathway for the water inside the pot to make its way into the soil below, the earth is essentially a giant wick and the container will act (hydrologically) like a raised bed, even if in miniature. Pot-in-pot or pot-in-trench applications essentially make the container you grow in into a mini raised bed IF the layer of soil in the bottom pot is at least as deep as the ht of the perched water column the soil in the growing pot will support; or, unless the lower pot is resting on the soil so there is a pathway water in the lower pot can follow into the earth, which would actually make the lower pot redundant.

"Barely connected" doesn't really diminish the effectiveness of the methodology, only the speed with which the main pot will drain - sort of like a normal pot with one small hole or 50 larger holes. The same amount of water will drain from the soil in either case (if the bottom of the pot is level), but the pot with more holes will drain a little faster. 1 minute vs 10 minutes really doesn't make much difference to a planting.

Al

Thank you so much for the responses everyone. I read every last one of them and keep them in my conscious thoughts.

Thank you specifically to Al for clarifying what I read in your other threads. I've learned a lot from you and I will be trying your gritty mix shortly. If you could clarify just one more thing for me for my own solace since I am a bit slower in the brain department. I want to make sure that I'm applying your concept correctly and not stretching it to irrational limits. What if my container has a very long length or say 8 feet and only the utmost 1 inch on the right of the edge is connected? I'm assuming the water from the areas of the enclosed part of the container would end up wicking over laterally to find that outlet into the ground eventually. The issue I'm worried about is how much laterally will the water wick over. Unlike the examples spoken about above, the container or nursery pot isn't directly on top of the soil, nowhere near but instead only the most lateral 1 inch edge touches. Would it be better for me to keep the non-connecting side of the container at a higher vertical level than the open side to encourage downward flowing so that basically the open connecting "wick" side would be the lowest point of the container.

If I remember correctly, a large wick in the form of a rope or such is all that's enough to make the connection according to what I read in your other thread. So if my container is placed on a concrete deck, I could just attach a rope to the bottom of the container and in ground soil area and that container would essentially be a raised bed/or extended part of the ground.

Thanks again for your clarification and sorry for the verbal mess. It's a bit difficult for me to express myself

Thanks for being so kind.

I understood what you're asking. If your container is level, you should be able to remove all or almost all of any perched water with a wick that's in contact with the soil. Since you're treating the wick and the earth as an extension of the soil column in the pot, the set-up you described should be as effective as it would be if it was resting entirely on the ground.

To imagine how the PWT would respond to tilting the container, just picture in your mind a waterline that remains at a given depth. If you raise one end of the container, it can drastically change the shape of the PWT ( but not the depth) which can have a significant impact on the volume of PW the soil can retain.

Note the difference in PW volume in B compared to A, just by tilting the container. It sounds like yours, because of its length, would see quite a significant difference. Then, if you combine the tipping with a wick, you're in really good shape.

Al

Al,

Would a soil in pot to mulch on the ground connection, whether in the form of dead leaves or wood chips, be just as effective as a soil to soil connection? I'm assuming the mulch will act as a wick to the soil below anyways.

What do you do with all your compost? I notice even in your raised beds you use a special mix with pine bark fines and spaghnum peat mixed with top soil and some other ingredients. But other then the spagnhum and pine bark which are both very specific types of organic matter, I don't see any signs of generalized compost in your raised bed recipe. Do you actually have a compost pile anywhere and if so what do you do with all of that since its not going in your containers or raised beds?

Have you ever used a conventional native top soil + compost mix in your garden and raised beds and if so, how did it compare to what you're using in your garden/raised beds now?

I'm not exactly the classiest gardener so all I can afford is the free stuff at the moment and that basically comes in the form of my native top soil and vegetable scraps or other yard waste that I can convert into compost :( .

Thanks again for everything.