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Smallest indoor plant?

Hello everyone!

I'm looking for recommendations on indoor plants which grow all year round and need as little space for roots as possible. More specifically, I'm doing an experiment where I physically separated my pot into 1 cm^3 (=1 ml) segments. I would like to grow a different plant in each of those small segments. Could you please give me some suggestions what plants would be appropriate? To summarize, the desired characteristics include:
- small root system
- low height of the plant (up to 5 cm / 2 inch)
- possible to plant the seed and grow it all year round for as long as possible (indoor!)
- easy to grow / maintain

It's bonus if the plant has nice leaves or flowers but it's not a ''must''

I would really appreciate any help since I'm new to gardening and kind of lost...

Thank you very much!

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Re: Smallest indoor plant?

If the soil volume is 1cm cubed there won't be much you can grow besides moss, some small succulents, and young cuttings or seeds (which would quickly outgrow the space). If you spaced it out into 3-5cm cubed or bigger you'd have more options. You also need to consider the amount of light the plants will get.
I'd try creeping thyme from seed (though it's more of an outdoor perennial) and take leaves from succulents to root. See if you can find mosses that might fit the space as well... I can't think of anything else that would work for such a small soil volume.

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Re: Smallest indoor plant?

If you look in this thread, you'll see references to soilblocks and micro blocks, including photos like this:

Subject: Finally! Off to a haphazard start for the 2014 season


These soilblocks are 1cm^3. There maybe other threads if you search our forum -- I think there is at least one soilblock thread in which I contributed some comments and photos.

My experience was that they are extremely persnickety to maintain, drying out easily and ambitious seedlings quickly outgrowing and snaking roots out to seek moisture and nutrients.

You could grow all kinds of seedlings from tiny seeds until they are too big, but you will need a very good lighting set up. Otherwise, I agree mosses and lichen ...maybe miniature ferns... may be the best choice in an indoor setting.

Mostly, I think you are looking at a very limited period until the plants outgrow the cube.
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Re: Smallest indoor plant?

Look up fairy gardens or miniature gardens for suggestions for very small plants: ... scapes.htm
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Re: Smallest indoor plant?

Thank you all for your prompt and extremely useful replies. So far I planted what was available at my local store: dichondra, wheat, lawn grass, dill and watercress.

Both moss and fern fascinate me and I've been studying them for the past few days but they seem quite demanding to cultivate in such small volume. Still, it's challenge so I'll try and report how it went.

Soilblocks seem to be the closest to my experiment. I would consider it a good result if plants managed to grow in the same setting for 3 - 6 months. Do you think this is possible according to your experience?

Also the link to miniature gardens has some very specific and interesting information, much appreciated. I might contact the author of the article, she seems like a very knowledgeable lady.

I'm very excited about this small ''project'' and look forward to sharing the results!

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Re: Smallest indoor plant?

1cm^3 is going to dry out extremely fast. Anything sensitive to that is not going to last very long.

You could probably grow some baby onions.
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