Do plants grow in river rocks?

[Ben P.]

I'm not much of a plant person but I'm trying to change that a bit with this tank.  It's a 20 long with a matten filter and a thin river rock substrate with no cap of finer substrate.  The stones are about 1-2 inches in diameter.  I'm just wondering if I'm limited to attaching water column feeding plants to the wood in the tank, or if plants like crypticorn (I tried to spell it) would grow well in just the rocks?  Thanks!

[Guppysnail]

I set up 2 tanks with shallow sand substrate only. I used rocks 1-2 inches big in a pile to weight down roots on several crypts. It did well and the crypts thrived without ever sending roots into the sand. I see no reason they would not do well for you. I do not use fertilizer or root tabs either. 

[Ben P.]

@Guppysnail even without the sand below the rocks? I'm doing nothing but larger river rocks

[Guppysnail]

On 9/26/2023 at 10:23 PM, Ben P. said:

@Guppysnail even without the sand below the rocks? I'm doing nothing but larger river rocks

Yup. I actually had one with just a plant weight in a bare bottom tank for about 6 months. It did just fine. 
there is circulation between those large rocks you use. That means the roots still get fresh nutrients. 

[Odd Duck]

I have Crypts that are growing weighted in bare bottom tanks.  As long as they have appropriate nutrients, Crypts will grow as epiphytes that don’t mind their roots being in any substrate you have.

[lefty o]

if the plant is in the aquarium water, it will feed from the water column.