You'd have to be very careful not to over-water, but there is no reason it couldn't work. If the stone is porous, it would be a lot safer.

Drill bits are available to drill through masonry pots. Ask at your nearest large hardware store or lumber yard. In some locales, they'll drill the holes for you if you bring in the empty pot. (Call first to ask.)

Beyond that, next time you purchase a pot-without-a-drain hole, ask the shop/store to drill holes for you.

No, the water won't evaporate. Instead, the potting mix will remain soggy and the roots will rot. Eventually the water-logged potting mix will stink so bad you'll wondered who died in there.

If you put gravel in the bottom, it must be a deep layer. And you must also install a stand pipe that extends from the bottom of the pot to the surface of the potting mix. The reason: so that you can siphon out any standing water.

In my climate the pot would very soon become waterlogged, whether you watered or not!

When you say stone do you mean actual rock, or stoneware, ie pottery? If the latter you can drill holes with a masonry bit and some care. A hand drill allows greater control than elctric. Turn the pot upside down and drill from the outside in because any flaking or chipping usually occurs on the exit side of the hole.

Alternatively, what I have done with several large, heavy earthenware pots is to use them as cache pots, ie buy a cheap plastic pot which fits inside the earthenware one with its lip just below the outer pot and space underneath for stones, broken pots or other drainage material. Then I plant up the plastic pot. The plastic pot will be hidden by foliage and cannot be seen. You can remove it and tip out excess water if you suspect it is gathering in the bottom of the outer pot. Furthermore, if you buy several inner pots you can change your display very easily without having to empty or move the heavy outer pot. I do this with my terra cotta window boxes and my earthenware chimney pots too.

Thanks for all of the advice. I acquired the pots through someone who is moving out. The pots are made of a texture kind of like a stone/cement. When I pick the pots up, I will post a picture.

If the container is quite light for its size, then it may be a constructed container called hypertufa.

If your pot does not drain, eventually salts will build up and kill your plants.

I have a dozen indoor plants that are in 'quaint' pottery pieces that I seem to accumulate. Which is why, when you get a quaint pottery piece for a birthday gift, don't be overly exuberant because then you start to get all kinds of quaint pottery pieces. Anyway, I use them for indoor plants - African violets, small vines, and such. I lose one every now and again by over-watering, but not that often. With careful watering, the plants roots will transpire the moisture on out of there.

Of course, if you have pots with holes in them, life is a lot easier.

David - I believe the OP's pots are destined to be used outdoors, so watering is much less controllable because of rain. Waterlogging is a real risk which transpiration will not cure.

Also, have you thought of using your pottery pots with no holes as cache pots, rather than actual plant pots? That would make life much easier for you and you wouldn't lose plants through over watering.

I would check for soil problems.. maybe you could do some soil diagnostics (in dutch: bodemanalyse) or soil improvement (in dutch: bodemverbetering).

Here is a link that might be useful: Terricola - biologische kuur

Or try a water garden if it is a really large pot that doesn't drain.

I picked up the huge pots. I think its made of cement. After carrying these 2 heavy things to my apartment, I realized that there are draining hole at the bottom. At least I dont have to drill holes. I was worried about cracking the pot. Thanks for all of the input ladies and gentlemen.

Glad you followed up and that your pots do have drainage holes. Still think flora UK has the best advice... since the pots are already heavy, filling them up with a gravel layer, then soil, etc. is going to make them even more unweildy. Find suitable plastic pots to fit inside and use the big containers as cache pots.

What if I have a bath tub old pond with no drain. Can I plant in it. It is impossible to drill holes. It also has a pond liner in it. I need help.

I have a really pretty large ceramic pot with no drainage, and it is an odd shape (not round) so I can't find any cache pots that sit correctly. I did read about the masonry bit to drill into pots, but this one is glazed so I feel like it would crack easily. I also don't have a masonry bit or a hand drill.

To solve my problem, I went to the store and bought some rocks (~$4 for 40lbs) and some sturdy 1/2 in plastic tubing (~$0.33 per foot). I put the tubing in the bottom of the pot and layered up larger rocks around it, then put in some smaller rocks in between the cracks so that I could not see the bottom of the pot anymore. I chose larger rocks for the bottom layers to avoid clogging my tubing with small rocks, and small rocks at the top so that my soil wouldn't fall down in between the larger rocks. The total depth of the rocks was around 3-4 inches. I added soil/plants on top of my contraption allowing the tubing to hang over the side of my pot. I am hoping that the rocks will allow good drainage to my soil and that I can siphon off extra water in the bottom of the pot as it collects.

I just put this together yesterday so I can't attest to how well it works, but I am hopeful since I read reference to this method earlier in the thread.

As a last note, the tubing doesn't look pretty coming out of it, but I hope plants will cover it up. I am also worried that the tubing will be yanked out of the soil, so I think I will tape it down to the back of the pot.