Imperialboy
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How to Clean and Disinfect Old Containers and Pots

. How?

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bonsaiboy
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There are a number of ways. I prefer to immerse them in hydrogen peroxide for about ten minutes.
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If you use any chemicals, make sure to rinse the containers out many times. You don't want the residue to be left when you put in soil or use them for hydroponics.
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Imperialboy
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Can anyone give me one the of the many ways to clean containers?
I've heard of bleach solutions. But someone give me a ratio or directions?

Thanks~

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Kisal
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Two tablespoons of standard household chlorine bleach to one quart of water should be a satisfactory solution. It's what I use.

First, remove any soil residue by washing the pot in clear water. Do not use soap, or things like S.O.S or Brillo pads that contain soap. You can use plain steel wool, if you like, but I prefer one of those metal mesh "scrubbie" things that are made for cleaning pots and pans. You can buy them at most grocery stores. Some are made of plastic, and they work okay, too. I find the metal ones to be better, though, especially when cleaning containers that have dried salt deposits on them. It's important to remove all the dirt and any organic material before soaking the pot in the bleach solution.

Soaking for 10 minutes should kill all bacteria and any fungal spores present on the pot. The solution will soak into ceramic pots, so even infectious agents that have penetrated the clay will be killed.

Chlorine is unstable and dissipates into the air quite readily. Just rinse the containers under clean water and set them aside to air dry. When the containers are thoroughly dry, the chlorine will be gone. (I use this method when I clean my hummingbird feeders, and I haven't lost a hummingbird yet. ;) )
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When I was making wine, I used a 5% bleach solution on food-grade plastics and glass which roughly translates to 1 cup of bleach for 20 cups of water. The temperature doesn't really matter. Then I rinsed the container out several times with fresh water. *Remember, more bleach does NOT equal more "killing power", a 5% solution sanitizes the same as a 50% solution.

For residual smells I cut a lemon in quarters and wipe the insides of the container or squeeze a little juice if I can't reach in and shake the container. Then you set it out in the sun for a few days and rinse thoroughly. Then I sanitize with the bleach solution.

I would think a simple thorough wash with dish soap (maybe antibacterial?) would be sufficient for planting containers if you rinse the container out several times afterward.

Don't know about clay or ceramic pots... : /
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Kisal
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Lehcar wrote:Don't know about clay or ceramic pots... : /
:lol: I do know about containers made of porous materials. I can tell you from experience that, if you use soap on them, you will spend days and days rinsing and soaking, and rinsing and soaking them, over and over again. Soap is okay on non-porous materials, such as glass and plastic, but it isn't enough to kill all the bad bacteria and fungal spores that can survive on the surfaces of a plant container.

I don't worry so much about disinfecting a container, if I'm sure the previous plant that lived in the container was healthy, but I always use a chlorine bleach solution for containers, regardless of what they're made of, when the plant had root rot or any other health problem ... including insect pests. I also use it for containers in which I intend to start seeds. JMO. :)
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Imperialboy
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So first scrub containers clean then I'll take 2 tablespoons of Clorox Bleach to 1 quart of water.

How do you soak it? Do you have a tub of the solution and just dunk the container in one at a time?

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Kisal
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Yes, you can use any watertight container, such as a tub or bucket or sink.

I usually clean a lot of containers at one time, so I first wash the containers in the sink in my utility room and set them aside on a towel. When they're all cleaned, I put the stopper in the sink drain and fill the sink about half full with water. That's just about the 20 gallons that Lehcar said he uses. Then I pour in anywhere from one to two cups of standard chlorine bleach, like you can buy at any supermarket. The ratio of bleach to water doesn't have to be exact, so if you added more bleach to the water, it would still be okay. It just wouldn't be as economical.

One teaspoon of bleach to 1 quart of water is probably the minimum strength that will work as a disinfecting solution. If you only have one or two containers to clean, then all you need is a tub or bucket large enough to submerge them. I like to completely submerge the containers, but it would also work to just cover them halfway with the bleach solution, to soak one side for 10 minutes, and then turn them over to soak the other side for 10 minutes. It's just a little faster to submerge them all the way.

If you haven't ever used chlorine bleach before, be sure to wear old clothing. Chlorine removes the color from fabrics, and it's really easy for a few drops to splash up while you're pouring it into the water.
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Imperialboy
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Kisal wrote:Yes, you can use any watertight container, such as a tub or bucket or sink.

I usually clean a lot of containers at one time, so I first wash the containers in the sink in my utility room and set them aside on a towel. When they're all cleaned, I put the stopper in the sink drain and fill the sink about half full with water. That's just about the 20 gallons that Lehcar said he uses. Then I pour in anywhere from one to two cups of standard chlorine bleach, like you can buy at any supermarket. The ratio of bleach to water doesn't have to be exact, so if you added more bleach to the water, it would still be okay. It just wouldn't be as economical.

One teaspoon of bleach to 1 quart of water is probably the minimum strength that will work as a disinfecting solution. If you only have one or two containers to clean, then all you need is a tub or bucket large enough to submerge them. I like to completely submerge the containers, but it would also work to just cover them halfway with the bleach solution, to soak one side for 10 minutes, and then turn them over to soak the other side for 10 minutes. It's just a little faster to submerge them all the way.

If you haven't ever used chlorine bleach before, be sure to wear old clothing. Chlorine removes the color from fabrics, and it's really easy for a few drops to splash up while you're pouring it into the water.
Great. I'll just find a tub to dunk them in. If I use like a 31 gallon tub, I'll just throw 2 1/2 cups in there or something

So dunk them in for 10 minutes, rinse, then air dry.

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Maybe I've just been lucky -- knock on wood -- but I never disinfect my containers other than drying them in the sun, if there is sun available. I do almost always use my own soil mix containing home made compost, and avoid using any chemicals that would disrupt the microbial diversity.

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Kisal
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Imperialboy wrote:Great. I'll just find a tub to dunk them in. If I use like a 31 gallon tub, I'll just throw 2 1/2 cups in there or something

So dunk them in for 10 minutes, rinse, then air dry.
That should work just fine. :)
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I'm with applestar. All the little pots I grow seedlings in, at the end of the season, I just rinse them out with water and a brush and air/sun dry. Never had any problem that way. They sit and wait 6 mos of the year so any disease/pest would have to survive in dry dark for all that time.
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Imperialboy
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Alright. I'll just dry them out in sun then
Saves time. The containers being reused are just transplant pots.

If my plants get a disease/pest. Then I'll know next year to bleach them [:

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Re: How to Clean and Disinfect Old Containers and Pots

How would I sterilize a window box connected to my house. They are too large for me to take down and immerse in water

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Re: How to Clean and Disinfect Old Containers and Pots

Personally I would only worry about sterilizing it if something that was in it contracted a plant disease, especially some kind of fungus that would survive in soil. In that case I would dig out and get rid of the soil, then scrub the box with a long handled brush and bleach solution. Rinse/ wipe it out as well as you can, then let it air and sun dry for at least a couple weeks. Refill with clean soil.

Otherwise, I would just keep adding new soil/compost to what is there.
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Re: How to Clean and Disinfect Old Containers and Pots

A further question on this topic: what if I don't have a tub large enough to submerge a pot? Can I spray it with the bleach solution, or, well, something else?

Thanks!

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Re: How to Clean and Disinfect Old Containers and Pots

I make a 10% bleach solution. I remove as much dirt and roots I can and then I soak my pots in a five gallon bucket for a week and sometimes up to a month. After that amount of time most of the bleach has dissipated, the pots are clean without even scrubbing and terra cotta calcium residues are mostly gone from the outside of most pots. The plastic pots can be rinsed and put away. Since terra cotta absorbs more, I rinse the pots out but soak them in water which gets changed daily for another three days to make sure anything in the terra cotta leaches out. I use terra cotta mostly for the orchids and succulents, it has not been a problem.

The old way to disinfect pots and plants was with Physan. It is a bench disinfectant, fungicide, virucide, and algaecide. While it is still available at agricultural suppliers it is really expensive.

I used it on the benches but it can also be used as a fungicide dip for orchids nd other plants. When orchids are repotted we often will dip orchids in a fungicide since they are very susceptible to fungal and bacterial rots. Unfortunately, orchid seed germination is dependent on certain species of fungi to succeed so the orchids do invite fungi and bacteria. However, not all fungi and bacteria present in a collection are the good kind, so the professional growers fungicide regularly. As a hobbyist, I just try to get by, so I lose a lot of my orchids in plastic pots, that is why I put most of the orchids in baskets or terra cotta.
https://www.physan.com/

P.S. It is o.k. to use cleaned pots on some plants. However, some plants that are especially prone to fungal, bacterial rots and viruses should always be in new pots whenever possible. Long term plants should be in new pots since they will be there a long time. Plastic pots these days are brittle and they don't last as long as the old pots.

Never reuse soil or a pot where the plant was virused. Viruses can remain viable on fomites. If you have a virused plants. Try not to touch it with your bare hands. Wear gloves; bag the whole plant pot and soil and dispose of it. Wash your hands after.
Tools should be disinfected after each cut or plant when you work on them. Orchidists use a small torch to heat the blade. Bleach and alcohol are other ways to disinfect tools between cuts, but they don't kill viruses. Utility knives with disposable blades is another way. People who have had to destroy collections and rebuild them have learned the hard way about the value of good sanitation.
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Re: How to Clean and Disinfect Old Containers and Pots

thebookfrog wrote:A further question on this topic: what if I don't have a tub large enough to submerge a pot? Can I spray it with the bleach solution, or, well, something else?

Thanks!
Never done it with pots, but have done this with a lot of +100 gallon aquariums.

Fill a spray bottle about 1/4 full of generic bleach and add tap water for the other 3/4's. Shake it up a bit. Start at the top and spray the hell out of it and go around in circles, maybe the top 4"-6" all the way around, then the next 4"-6" all the way around. Really saturate the area so the bleach solution runs down the sides.

Once you have sprayed the whole thing, you can use a brush/scrubbie/sponge/scotch bright pad to slop the solution out of the bottom and back up onto any problem areas. Have at it until you are sick of the smell, get bored or have nothing left to clean.

Use a old towel or similar to soak up the solution in the bottom for disposal. Once you have as much of the liquid out as you can get out. Spray the whole thing down inside and out with fresh tap water. Get the water out and let air dry. If you get white 'dust' once it is dry, rinse it again.

When there is no more bleach smell, there is no more bleach. Sodium hypochlorite (bleach) is pretty unstable if exposed to ambient air and will react with most things it encounters, so there is a every short period where the cleaning residue is "bleach".

REMEMBER to do do the outside as well as the inside, or what ever you are trying to kill off will creep right back in.
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Re: How to Clean and Disinfect Old Containers and Pots

Good technique! I actually have a tall octagonal aquarium I have to clean and was wondering how. Thanks!

Definitely sounds like a good method for washing/cleaning large pots. :D
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Re: How to Clean and Disinfect Old Containers and Pots

It is messy, but it works. If it is one of those octagonal towers between 3' - 6', get a new string mop or similar, get some solution in the bottom and just mop the sides.
(ever try to find a container big enough to soak a 250 gallon aquarium?)
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Re: How to Clean and Disinfect Old Containers and Pots

Mix a 9 parts warm water and 1 part bleach in a spray bottle (10% solution). Clean the window box of as much of the dirt as you can. Spray the box with the bleach solution and let it sit for about an hour. Rinse well with water. Let the box air out until you cannot smell the bleach.
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