Does dishwasher disinfect pots?

[PaphLover]

Looking for opinions on washing plastic pots in dishwasher. Will this kill any pests/ disease/ viruses so that the pot can be used again for repotting of new plants? I'm a window-sill grower and have done this in the past thinking the dishwasher's hot water and heated dry cycle should kill anything that might have been in pot. But is this a dangerous practice that leaves new plants susceptible to possible infestations/ transmissions?

What about enamel-coated clay pots? How are they best handled?

What are best practices for re-using pots?

Thanks!

[Leafmite]

I don't have a dishwasher so I don't really know. I bake, boil or bleach, depending on what it is I am sterilizing. However, for me, it has always been guesswork on how long to bake or boil as it is difficult to find results on any experiments done to kill plant viruses. Hopefully someone out there can give you accurate information.

[Paphluvr]

I always use a 10% bleach solution soak followed by a good rinse and air drying before use, especially on a clay pot.

[estación seca]

Dishwashers generally get to only 160 F / 72C, just hot enough to kill most bacteria causing food-borne illnesses. This is not hot enough to kill most viruses, fungi, nor spores of many bacteria. Dishwasher detergents intended for home use are formulated to remove food particles from dishes, not disinfect them, though this happens to some degree. Dishwashers are singularly bad at removing food or other material from porous surfaces. Commercial dish sanitizer machines are intended for already-clean dishes, and the chemicals added are not in typical home dishwasher detergents.

It is reasonable to run pots through a dishwasher to remove as much soil as possible, since this sort of material can hide microbes from later soaks in effective disinfectants.

Most plastic pots would melt at temperatures adequate to kill microbes without added disinfectants. Soaking in a bleach solution for several hours is the best bet.

[Orchid Whisperer]

I agree with estacion seca. I use the following procedures for two different pot materials, plastic and ceramic:

1. For both, the following steps:
- Stiff brush scrub with detergent to remove as much surface dirt and plant material as possible. rinse.
- Long soak (24 hours) in 10 % household bleach solution. This oxidizes and destroys any remaining organic matter, fungi, viruses on the surface of pots.
- rinse in fresh water

2. For ceramic:
- extended soak in bucket of fresh water (several days)
- air dry
- place ceramic pots in oven. SLOWLY raise temperature - start at 200 F (100 C), leave at that temperature up to 1/2 hour, then raise in steps of about 25 F each over a couple of hours until you are at 450 F, leave at that temperature a half hour, turn off oven until cool.

[estación seca]

I don't use the oven method any more. If there is the tiniest air pocket trapped in the clay the whole thing can explode in the oven. This has happened to me. I would have thought it would have happened during the original firing.

[Ray]

I doubt that your "exploding" pot was due to an air pocket. Pots are pressed, allowed to dry, then fired to a lot higher temperature than your oven even dreams about. The clay is very porous, so anything trapped would have reared its ugly face in the firing process.

More likely, there was some sort of "stress raiser" was in the clay body, just looking for an excuse to release its energy, and your oven heating gave it that opportunity.

Sometimes, ground up, already-fired material - grog - is added to the green clay intentionally, and sometimes the raw materials contained a pebble of some foreign material, and while it piece makes it through firing fine, it's a time bomb, waiting to go off.

[PaphLover]

Excellent info. Thanks! I've never used bleach in my home--always too nervous to get white spots on my clothes in the wash, so this will be new for me. Wish me luck.

[estación seca]

Either wear white clothing when dealing with bleach or don't wear clothing at all.

[PaphLover]

Ouchie!