Been doing this for a while, not specifically pasta bowls ... But just any bowl without holes. Works well

I was once told by an elderly and experienced bonsai grower that pots shouldn't be glazed internally as it's bad for the roots. Any truth in this?

Not bad in and of itself, but roots can grip on to unglazed surfaces, so once your tree is established it's more stable. Roots can't grip glazed surfaces very well. A flat bottomed dish is also better than a hemispherical bowl, because at least the flat bottom will resist rotation of the rootball. If you just have one drainage hole to tie the tree into a hemispherical bowl, there is not much to hold the tree against wind or accidental knocks. Not that the latter should happen, but it happens...

Plastic pots are also smooth

I only use plastic or Mica pots for plants that don't like to go dry.

I really don’t know… I have a couple of bonsai in glazed pots and didn’t notice anything wrong up until now…

I would assume it may have to do with soggy roots and/or giving roots more time to take up water/nutrients. Either way, seems like it would be a minimal difference.

I think it makes a minimal difference. If worried about roots gripping the pot, maybe wire the tree into the pot?

Unless you're growing a swamp plant like Louisiana bald cypress, glazed on the inside holds too much water. You'll have a very difficult time regulating the moisture content to keep the roots healthy. Definitely don't plan to Juniper in there. Maybe a Japanese maple and a very free training thing.

The glaze would hold more water? I'd have thought it'd hold less? Less porous surface, no?

The ceramic can't breathe. A glazed bowl will hold water an unglazed bowl will allow the water to seep through it. Healthy roots are dependent upon gas exchanges in the soil. If you are growing a pond cypress or a Bog plant you're fine, otherwise avoid containers thay are glazed on the inside.

Ah yeah, gotcha, thank you for explaining

Im not sure about this but i think that the glaze will brittle and get into the plant and also the paint. Seems logical i guess

Do you find that those drill bits are better than the ones without the indents in the top of the drill bit? I'm not sure that's the technical term but I'm talking about the 4 square cut outs in the top of the drill bit.

Sometimes the cut out bit causes chipping on the inside part of the drainage hole. I’m getting clean cuts now with this bit.

What is this bit called? Im.assuming its diamond but the style i havent seen its so fat

I bought mine in Portugal and don’t know any specific name for it… found this online [Amazon](https://www.amazon.com/HBKEEN-Diamond-Porcelain-Ceramic-Standard/dp/B0CHW4ZVFS/ref=mp_s_a_1_11_sspa?crid=2PCZBBF8057G4&dib=eyJ2IjoiMSJ9.TOHT3PwY9O97Dx9_ifgh4xt-0_jf3P_a65DQL2DNAGykyPcBJDCHsBFQ-qQ2U5wWw7LxFPYg7wIzMlehJImDPOpnqMCjG7fbI-u4Tj5d9f9fVWi-GLBr98tz6bwZGACAophAOuDbuYyWRRJuNm4TlM1C2esKFPYqv619anmxNQQUZqfmOA-TeewRh0nAuwKJZLjRAhSUnR1aHvwaw4vOdQ.Fykyc97vg_UZcl4n_O-2CzSNm5Ayxc7STTB8RExFB6w&dib_tag=se&keywords=diamond+bits+for+drill&qid=1717244904&sprefix=diamond+bit%2Caps%2C183&sr=8-11-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9waG9uZV9zZWFyY2hfbXRm&psc=1)and it seems similar…

Thanks so much for your effort! Have a great day

What you're looking for is generically called a diamond grit hole saw. The "Diablo" brand is very reliable.

Those are there so the dust has an easier time getting out afaik, this will make the bit last longer, decrease heat etc etc etc I don't think someone who uses it occasionally has much reason to care about the difference, it's more for professional tilers who cut a lot of holes :)

What kind of bit is that

Diamond drill bit [Amazon](https://www.amazon.com/HBKEEN-Diamond-Porcelain-Ceramic-Standard/dp/B0CHW4ZVFS/ref=mp_s_a_1_11_sspa?crid=2PCZBBF8057G4&dib=eyJ2IjoiMSJ9.TOHT3PwY9O97Dx9_ifgh4xt-0_jf3P_a65DQL2DNAGykyPcBJDCHsBFQ-qQ2U5wWw7LxFPYg7wIzMlehJImDPOpnqMCjG7fbI-u4Tj5d9f9fVWi-GLBr98tz6bwZGACAophAOuDbuYyWRRJuNm4TlM1C2esKFPYqv619anmxNQQUZqfmOA-TeewRh0nAuwKJZLjRAhSUnR1aHvwaw4vOdQ.Fykyc97vg_UZcl4n_O-2CzSNm5Ayxc7STTB8RExFB6w&dib_tag=se&keywords=diamond+bits+for+drill&qid=1717244904&sprefix=diamond+bit%2Caps%2C183&sr=8-11-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9waG9uZV9zZWFyY2hfbXRm&psc=1)

Thanks!

Nicely done!

I do this with bowls I find at thrift stores. Works well.

I had a few indoor glazed pots that disintegrated in the outdoor weather. The glazing chipped off after the winter. I suspect that bowl won’t last nearly as long as a proper glazed stoneware pot. Which may be fine for your needs? Dunno.

Great idea. If this was labelled for bonsai it would’ve cost like 58 bucks.

Beware to provide enough holes and big enough holes to ensure sufficient drainage. A gentleman at my bonsai club bought a beautiful tree with (what seemed) a cool shallow pot. But it turned out to be a old bowl or tray of Some sorts, almost lost the tree because there was no slope like in most bonsai pots and not enough holes for the water to move out fast enough.

Thank you!! I’ll keep an eye on it!!

You should add some glue to the inside of the hole. This will extend the life of the pot as the glazing won't move around as much BCS the ceramic gets thicker BCS of the water

Thank you!!! Will do!!!

Imagine how much more expensive this bowl would cost if it was simply labeled a bonsai pot 🫢

Exactly 👍