One of the things I like about clay pots is the soil dries out faster in them which makes it easier for me to avoid over-watering.

I was wondering if anyone on here has ever compared glazed clay to just plain clay?

What about glazed clay to plastic planters?

What are some other choices that would allow for a faster drying soil?

Thx!

Glazed pots are sealed on the outside, so don't breathe like clay pots. In my experience, they hold moisture more than clay. Something to consider: most if not all glazed pots have only one central drain hole. Many plastic pots have several, so plastic might drain better. Overall, I think pot drainage and well-draining growing medium are the two important factors to preventing overwatering. (besides, well, watering too much )

Have you ever tried fabric grow bags? Some gardeners swear by them.

Unglazed clay does move water from inside the pot to the outside. Obviously, glazed and plastic cannot. But I don't think this is a major factor in preventing over-watering. Roots drown faster than clay evaporation can protect against. Clay transmits water most readily when the outside surface in in contact with a medium capable of actively transporting water away from it, such as with a clay olla buried in soil or a Forsyth pot in rooting medium.

There is also some cooling effect from unglazed clay as water evaporated from the surface. Again, not a bit factor.

Some people practice and advocate removing the bottoms of pots, which greatly improves drainage by emulating natural ground. This is primarily a way to garden where hard, compacted ground is difficult to rehab. Roots do grow into the ground below the pot. But it opens possibilities like using clay chimney flue, sewer pipe, iron pipe, etc.

When a bottomless pot is set so that the open bottom is in the air and some sort of mesh contains the soil, roots will generally air prune. In any events, the open bottom provides the best possible aeration with a container. And aeration is really what we talk about when we talk about over-watering.

IntheHotofTexas said:Obviously, glazed and plastic cannot.

Oh my goodness, that's what made sense to me too!!

The reason for the post was because I asked this lady at the nursery if glazed was slow to dry in comparison to clay and she said,

"NOT AT ALL."

She seemed so sure but it just didn't sound right to me.

It would be one thing if she said,

"Meh, I doubt it."

But such an assertion just didn't sound right.

IntheHotofTexas said:

When a bottomless pot is set so that the open bottom is in the air and some sort of mesh contains the soil, roots will generally air prune.

What is "air prune"?

Air pruning is where roots that are exposed to air in a low humidity environment turn off that growth and grow more actively in the moist environment. In one example, plants are grown in openwork containers, like mesh or open weave. When roots reach the limits of the container, they turn off and stop, rather than circling and becoming root bound.

There are air pruning pots you can buy. The goal is to provide a plant with a dense root mass, full of carbohydrates, and ready to burst forth when removed from the pot and planted. Buying plants in air pots helps insure they aren't root bound and crippled. Nurseries like them because they can take up minimal space without causing root binding. It's really a way to keep a plant healthy in a pot that would normally be too small. Or just to provide a healthy well-aerated soil.

Notice how this commercial product has perforated sides and a mesh bottom that is held off the ground, thus air pruning. It's pretty hard to over-water a plant in these. Grow bags that aren't too dense will air prune. Roots reach the arid outer walls and shut down before circling. Keep the grow bag off ground contact for best results.

Once you see the principle, you can come up with all sorts of ways to accomplish it. You can buy Rigid Polyethylene Garden's Drainage Mesh Hole Screens from Amazon. You can use dimpled rigid poly wall drain from Lowes, but you have to drill out the center of the dimples.

https://air-pot.com/nursery/

Interesting, Gerald. Thanks for the link.

Depending on the size of the pot, I put 3-6 inches of wood mulch on the bottom of them, separated by a layer of porous garden fabric. It allows for proper drainage, but it also stays moist without the added weight of rocks or stones. The roots do not sit in water, but it sort of seems to "self water" to some degree by keeping the lower layer of soil moist. This works best with annuals--because with perennials--the soil itself doesn't seem to last for more than a season or two and I have to empty it out and a add a new batch.

We have long hot & humid summers. I have a lot of glazed pots. I still have to water frequently. I don't think the sealed nature of glazed pots or even plastic is much of a factor in moisture control. Porous outer surfaces can wick moisture to the outside but at what speed? I think it's more drainage.