disinfecting used unglazed clay pots

[neophyte]

I'm running out of unglazed clay pots so I decided to reuse some old ones. The problem is, the only ones I have contain the remnants of several dead divisions of a Dendrobium that died days after I repotted them separately (the canes just instantly started yellowing and the leaves were dropping, and within a couple days they were all goners). I don't want that to happen again, so I want to disinfect the pots. Can I literally stick the pot into a pressure cooker? Or can I boil the pot in water? Or is rubbing alcohol sufficient?

[SouthPark]

neo ------ definitely. Once the pot is heated to high enough temperature, it will definitely wipe out all possible nasties.

Just make sure to be gentle in the boiling, if you boil that is. So that the forces don't shake the clay pot apart or split it. And ---- not sure about the temperature expansion/contraction rate ..... just cool it back down relatively slowly --- just in case. To avoid cracking. But maybe the pot can handle it even if you just remove it from the water after boiling.

A pressure cooker should do the trick too. As long as the pot fits in there nicely, then should be fine.

A steamer ----- such as a big pot with water in the bottom, boiling, and orchid-pot raised above water with the main pot lid/cover closed ...... would also do the trick.

[DirtyCoconuts]

bleach soak is also fine

i keep old pots in my swimming pool to clean them

[neophyte]

I might try to just boil it with Southpark's advice in mind but if I could use a disinfecting agent I would. :P

DC - is a quick wipe-down/dunk fine or do I have to keep it in the bleach solution for longer?

[Roberta]

If these are clay pots, they can take lots of heat if dry and the temperature changes slowly... you could put them in the oven, crank it up to 350-400 deg F or so, leave for half an hour, turn off and let cool. Nothing infectious will survive that (though if you leave a lot of stuck-on plant matter it may stink up the house as it burns... suggest you clean off the mess first)

[DirtyCoconuts]

Okay, two options. Do you have either a large Tupperware tub (like over 75 L)?
Two do you have a pressure washer?

What I would do; take pressure washer OR wire brush, clean the surface of the pots well, put in oven and slowly heat to 400....then do similar to a glass annealing...let temp lower slowly to room temp
This is just to avoid stress in the pots making them more likely to crack

As for the first question..
If I have to do a quick clean, I have a medium size plastic container and I do a pretty strong bleach bath...I pour about a half a normal bottle of bleach and then fill...it juuuuuat stings my eyes to be near it lol

I put any quick pots in that overnight


I do this rarely bc I have about 45 pots in my pool for
Weeks-months lol

[Ray]

Terra cotta is quite porous. If you do a soak (bleach or physan) leave it for at least overnight. Surface wiping won't do much at all.

[neophyte]

I soaked the pot in bleach solution overnight and I've moved it into pure water. Is this the best way to get rid of the bleach, or should I just leave it in the sun and let it dry?

[Roberta]

Originally Posted by neophyte

I soaked the pot in bleach solution overnight and I've moved it into pure water. Is this the best way to get rid of the bleach, or should I just leave it in the sun and let it dry?

The pure water soak should do the job - the need for that isn't the chlorine, but rather the sodium hydroxide that keeps it in solution (to make sodium hypochlorite) Once the sodium hydroxide concentration is reduced by the pure water soak, any chlorine will just evaporate.

[neophyte]

Thanks Roberta. How long should I soak the pot in pure water? More than overnight?