Where I live we try to get rid of horse tail so maybe post a pic of the plant and where you are using it. I find grasses do best out of containers and you do not cut them down in the winter but keep them for winter interest they will come back larger each year.

So here are some pictures from last year. I was hoping they would give full coverage. They are sitting in the center of A 15x20 patio.I see where I potted each horsetail and no blending of the growth between the plants. I have a chance to replace them. I in error on a recommendation on Pinterest to get rid of an invasion of weeds I poured Apple cider vinegar on them that killed the horsetail. So I am trying what is the best option of purchasing horsetail to get the best option of full thick coverage that I see in some pictorial examples.

Not sure where you are located (might have a bearing) but the common horsetail grown for containers, Equisetum hymale, is typically considered fully evergreen and is not cut back. In fact, it is the very vertical structure that gives this plant its winter container appeal. And they do not spread readily in containers....most sources suggest selecting a container to fit the plant as it is in its nursery container OR purchasing enough to fully fill your planter or container.

btw, horsetail is NOT a grass - it is an ancient plant most closely related to ferns - and if being grown intentionally, it should ONLY be planted in a container due to its garden invasive nature.

I live in Atlanta, GA

Excellent!! Then all the above applies.

Thank You!! I just purchased eight one gallon planters to start. Depending on how many I can fill the planter with will determine the remaining number to buy for the remaining two planters

Thanks for the picture I was not sure if it was the same horsetail as we have .Those planters look very full to me I am not sure what you wanted from this very vertical plant.To me they are growing exactly as they should maybe what you need is a different plant. BTW weeding in a pot is best done by hand

Just to confirm OP’s plant is Equisetum hyemale, not E arvense which is the commonest weedy species.

garden gal,,,, would the sansevieria also be considered invasive? along my pond edge I've planted it (I used to have the horsetail but it was popping up everywhere close by) because I wanted that height. now the 'snake plant' has gone out of control. (rhizomes, yes?)

this was it at the beginning,

but now they are all bunched in and overcrowded.

'm thinning and plucking new growth but they just go berserk. (you can tell which side gets more water,, the roots grow into the pond water) any other alternatives?

excuse the hi-jack.