I can't think of any reason a glazed interior would have any negative effect to any plants you would put in it. I'm experimenting with the durability of spray liquid rubber products, on the insides of terracotta pots. I want to decorate the outside of them with paint or stain, and not have to worry about the soil's moisture ruining the finish.

A glazed interior would prevent the pot absorbing moisture into it's structure.

It is this moisture that expands on freezing and cracks the pot.

As I understand it frost proof pots are fired at a higher temperature to dissipate as much moisture from the clay as possible.

A glazed interior is no different to having a plastic pot as far as the hosta is concerned.

Go ahead and glaze or not. The worst that can happen, whatever it is, will not affect the hosta.

Dave

an UNglazed pot is a watering issue ... and a winter issue ...

watering in the sense that the pot can wick water out of the media ... i am sure that can be overcome.. by inserting finger and water when necessary ... until you learn how to water it ...

and a winter issue in the great frozen north .... as a sodden clay pot can crack.. when the wet media expands upon freezing solid ...

in either case.. its not really about the plant you put in the pot ...

btw ... if its heavy now.. dont forget to add the weight of the damp media... when hoicking it to the garage for winter ...

that said .....if you have the option of glazing it.. i dont know why you would skip it ...

ken

Thanks, all!

Since all my commercial pots came unglazed inside, I did wonder. I will go ahead and glaze this one inside.

Steve, I’d be interested to know how your experiments work out. Long ago, when I first got a deck and started putting annuals out on it, I decoratively painted a lot of clay pots to get something attractive without spending much money. Then when moisture coming from inside lifted off the paint, and salt came through to the outside, they looked terrible.

Now on the deck all the pots are either plain clay or the lightweight foam kind in a clay look-alike color. But I have part shade back there, so watering is not a huge chore.

In the front I have a large multi-level paver patio. That’s where all the glazed pots are. It gets more sun and heat in the morning to early afternoon. If I had plain clay there I’d be watering twice a day.

I have never grown a perennial in a pot until last year. I moved a mini I’ve had for ~ 5 years, Peanut, that had always looked scruffy and holey. It was either throw it out in disgust, or try a pot. It tripled in size in the pot and flourished. I am overwintering that outside, in the shade under the eaves and under a juniper. It is a plastic pot. It is turned on its side with
wire mesh wired over it to keep my aggressive squirrels out. I’ll see if it makes it.

This gave me the idea to try more minis in pots. I’d see them better, and some just might prefer it. I can move the pot around if they end up needing more shade.

Ken, wet clay is very heavy. It will be much lighter after drying and firing. So once it has soil in it, it might be about the same as it is now. I have a wheeled plant stand I use when hauling my big pots in and out.