bleach spray

[b54red]

I want to clear the air so to speak on my use of a diluted bleach spray that I have found to be very effective in treating all manner of foliage diseases. I have used it successfully on tomatoes, peppers, squash, beans, cucumbers, onions and roses. I'm sure it would work on other plants but these are the ones that frequently get foliage diseases.

First of all it is not a last resort or nuclear option. It is very important for it to be used early in the disease stage for it to be most effective. To wait only allows the diseases to affect more plant tissue which will be damaged by the bleach spray. The biggest problem that people have with using it is waiting too long to use it. It is almost pointless to wait til your plant is totally diseased to use the bleach spray as most of the plant will wither when the diseased tissue reacts to the bleach spray. I have posted pictures of my plants in the photo section and all of them have received at least 3 treatments with the bleach solution and the tomatoes have received 5 treatments so far. As can be seen in the photos the plants are healthy and growing and setting fruit very well. I live in an area with very high humidity and heavy disease pressure and I have a lot of experience using the bleach spray so I use it more often than many would be comfortable with.

Second the bleach spray does nothing to prevent new outbreaks of disease, other than killing the spores present on the plant, because it oxidizes so fast that it is gone in a matter of minutes after spraying. If you live where diseases appear frequently it is very important to use some type of fungicide as a preventative and to keep plants pruned to allow air and light into them to reduce conditions which allow diseases to develop and spread rapidly.

First off let me warn you that they have changed the formulation of Clorox so it is much stronger than it used to be. Check and see if you have the older formula with 6% sodium hypochlorite or the new concentrated formula that has 8.25% sodium hypochlorite.
*If you have the new concentrated regular Clorox with the 8.25% sodium hypochlorite then use one full gallon of water and add 5 ounces of bleach and a few drops of dish washing soap.
*If you have the old formula with the 6% sodium hypochlorite then start with one gallon of water and add 7 ounces of bleach and some dish washing soap.
These are the formulas I use more frequently. If it is very rainy and wet or I'm dealing with a very bad outbreak I will up the strength of my solution a bit starting by increasing the bleach in the solution by 1/2 ounce the first time and by 1 ounce the second time. I rarely use it stronger than that as leaf burn on new growth can occur.

I prefer spraying very late in the day when the sun is down. You can spray before sunup very early in the morning. If the plants are wet you can boost the strength of your mixture a bit but don't over do it. Start out with a slightly lower strength for your first spraying and see how the plants react to it before going with the stronger mix. Try to spray with a fine mist and hit all portions of the plant and even the mulch or ground under the plant. Give it two full days and then check the plants and see how well it has killed off whatever disease you are fighting. Clip off the dead and dying leaves and respray if necessary. Then follow up with a fungicide for prevention and if the diseases return you can treat again. During times of extended rainfall when fungicides won't remain on the plants you can go out and spray this bleach solution on the plants when it isn't raining. If the leaves are very wet then you can increase the strength of the formula just a bit since the wet leaves will dilute it further but don't over do it.

Make sure to rinse and clear your sprayer immediately after using any bleach solution as they are very corrosive. Make sure to never add any other chemicals to a bleach solution except a few drops of dish washing soap as a surfactant. Discard any unused spray solution and make new each time. I use a SP Systems backpack sprayer that is approved for mild bleach solutions so I haven't had any problems with it messing up anything on my sprayer but it will mess up a little bottle sprayer pump fairly quickly so if you use one of them make sure you rinse and clear it. It will rust a metal sprayer if left in it too long.

This spray will not help with any kind of systemic disease like fusarium or TSWV. As a matter of fact it really can be helpful in diagnosing some diseases because it is so effective against molds and fungi that the quick reaction to it will tell you that you are probably dealing with a treatable disease and if you get no reaction from the spray treatment then you are dealing with something like a systemic disease or a deficiency of some sort.

If you are afraid of using this solution on all of your plants then by all means I recommend just trying it on a few of the worst ones and see how it works on them before using it on more. I am amazed at the lengths some will go to, using very expensive and usually ineffective treatments when a safe, fairly cheap, and easy one to use is readily available just sitting in their laundry room. I am a big proponent of using the bleach solution because I have seen how well it can work if used correctly and early enough. I hope this will help some of you having issues with hard to control outbreaks of diseases and in answering some of the questions on the subject of the bleach spray.

Bill

[ChrisK]

Timely post, thanks! I was thinking this morning I needed to try the bleach spray! You saved me a search. I am starting to see diseases show up here with the cool wet spring we've had.

Ever use a hose-end sprayer which should be easier to use?

[b54red]

Originally Posted by ChrisK

Timely post, thanks! I was thinking this morning I needed to try the bleach spray! You saved me a search. I am starting to see diseases show up here with the cool wet spring we've had.

Ever use a hose-end sprayer which should be easier to use?

I have but they aren't as exact and it is harder to get the bottoms of the leaves. It also applies a lot more than is necessary and you get much more puddling on the leaves.

Bill

[ChrisK]

Tried it tonight just after dusk with the hose-end @ 4 oz per gallon with 8.25% hypochlorite bleach. Did it as lightly as I could....hope it isn't phytotoxic..or you get to face my wife!!

Originally Posted by b54red

I have but they aren't as exact and it is harder to get the bottoms of the leaves. It also applies a lot more than is necessary and you get much more puddling on the leaves.

Bill

[b54red]

Originally Posted by ChrisK

Tried it tonight just after dusk with the hose-end @ 4 oz per gallon with 8.25% hypochlorite bleach. Did it as lightly as I could....hope it isn't phytotoxic..or you get to face my wife!!

The problem with a hose end sprayer for applying foliar sprays is you get quite a bit of puddling on the leaves and it is harder to get the undersides of the leaves. As long as your hose end sprayer accurately dispenses the designated amount you should not have any problems.

Bill

[macbettz]

this might be a silly question but can the dilute bleach spray ruin your clothes should any overspray or droplets get on your shirt?

[rick9748]

Must get under leaves as well as top.

[amideutch]

Bill, so what your saying is if I spray a healthy plant with diluted beach as a preventative nothing will happen to the plant and will have no effect on it what so ever.

Ami

[b54red]

Originally Posted by amideutch

Bill, so what your saying is if I spray a healthy plant with diluted beach as a preventative nothing will happen to the plant and will have no effect on it what so ever.

Ami

Ami,

You are basically correct except it isn't a preventative. If there is no type of fungus or disease for it to react with nothing happens as long as the mix is not too strong and not sprayed in direct sunlight. I don't spray plants showing no signs of disease unless we have had a long rainy spell in which case I know some disease is there despite not being able to see it. I frequently spray my seedlings before they are potted up with a fine mist if they look like they may be getting some disease symptoms. The younger the plant the more sensitive it is so when spraying seedlings I use a milder solution. Plants that have been hardened off and are in the outdoors can be sprayed with the regular mix with no ill effects that I have been able to see. Bleach at full strength or at a high concentration will dissolve cellulose so of course if you spray plants with a very strong solution a lot of damage would be done to them. When I first started experimenting with this I consulted two chemist friends about it and both were of the opinion if I could find a solution that was strong enough to kill diseases without damaging the healthy growth that it would work. I wasn't sure when I began that I would find that happy balance. I started out with a solution way too strong and got a good bit of leaf burn then next went to one that was so weak it didn't kill enough of the diseases to be worth using. It took a lot of trial and error experimenting before I found that happy medium. There are a few diseases that are more difficult to control and I sometimes get my mix a little strong when dealing with them and get some leaf burn on healthy tissue. I would rather have a little leaf burn than a dead plant so in those cases it isn't much of a trade off. The big trade off is when you wait too long and allow diseases to take over a plant before using it. If you use it then you are going to lose a lot of foliage and there might not be enough healthy plant left to be worth the trouble.

I doubt I would have ever gone to the trouble to learn how to use this with all the experimenting that I had to do if I lived where the disease pressure was more moderate. It is a result of total frustration with all the products that are out there that supposedly help with tomato leaf diseases. I tried nearly all of them with limited success but with a much lighter wallet. I finally tried what I found by pure accident while cleaning mildew off my house one summer. I was using a 20% solution of bleach and rinsing it off and got a bunch of it on a climbing rose that was riddled with spot diseases. I tried rinsing it off with fresh water when I realized so much had hit the plant but the next day half the leaves were gone. A few days later I noticed that the leaves that fell off were the ones with spots and the others were fine. That summer was the best that rose had looked in years. That was the far too strong solution I used first on a tomato plant riddled with Early Blight and Powdery Mildew. Anyway that is how it got started for me and I'm happy it did every tomato season.

All of my plants in those pictures were sprayed from the very top to the bottom every time I treated them with no harm to the new growth and healthy leaves. Many of the lower leaves were diseased. I have already had to battle a bit of Early Blight, Powdery Mildew and Gray Mold so the infected leaves either withered up or had enough dead spots on them a few days after spraying that I went ahead and removed them. Had I not sprayed many of those plants would now be near death because many diseases just keep going up the plant at a rapid rate if nothing is done to stop it in my hot and humid climate. Two years ago I lost nearly a third of my plants by this time to Gray Mold because I waited too long and kept expecting the fungicides I was using to stop it from spreading but they did not. I had to learn that lesson like most I have learned the hard way. Now if at all possible I will spray a plant the afternoon of discovering active disease on the plant. I still use fungicides and they are a big help especially when it isn't too rainy and humid and that would probably be enough in a lot of places to keep plants fairly disease free.

Bill

[socalgardengal]

Hi Bill, Do you think it would work on Anthracnose? I have it on my Chayote squash real bad. I keep cutting the leaves off then it starts to grow well again only to return. Thank you. Christine

[b54red]

I don't know. Try it on one of them and see how it works. Do it late in the evening and spray all of the plant including the mulch or soil underneath the plant. You don't have to soak the plant just use a fine mist and wet all parts lightly. Let me know if it works. I would guess it would but it will not prevent new cases so you might want to apply a fungicide the next day that is recommended for it.

Bill

[ChrisK]

Sorry, one little point of clarification...do you add the bleach to a gallon of water or bring the vol up to a gallon ie do you end up with 128 oz or 133 oz?

Just curious b/c I'm doing the dilution calc for my 3% hypochlorite brand X bleach. It's about 0.32% final concentration of hypochlorite in your spray. I need ~13 oz bleach per gallon.

Tried it tonight on a few plants, we'll see how it goes. A couple of dwarfs have some kind of foliage disease. And PM is starting on the zukes and cukes.

[b54red]

Originally Posted by ChrisK

Sorry, one little point of clarification...do you add the bleach to a gallon of water or bring the vol up to a gallon ie do you end up with 128 oz or 133 oz?

Just curious b/c I'm doing the dilution calc for my 3% hypochlorite brand X bleach. It's about 0.32% final concentration of hypochlorite in your spray. I need ~13 oz bleach per gallon.

Tried it tonight on a few plants, we'll see how it goes. A couple of dwarfs have some kind of foliage disease. And PM is starting on the zukes and cukes.

Wow that is some weak bleach. That is one reason I use the Clorox brand because one bottle goes a long way used this way. They always list their formula on the label and some brands don't even do that and they change from bottle to bottle. I have run into some inconsistencies in the batches from some of the off brands and if you happen to get some that is much stronger than the label states then you could do some damage to your plants without even knowing why.

I would estimate to match the old formula I use you would need to add 14 ounces of the weaker bleach you have to a full gallon of water. The 13 ounces you used should give you enough for it to be effective and no harm in trying it a bit weaker the first time anyway. You will probably see some changes by this afternoon especially on the Powdery Mildew. I hate that stuff. It is the bane of growing cukes and squash down here with our very high humidity. It needs to be treated very early to stop it and not damage the plants because it spreads so fast.

I add the bleach to a full gallon of water. The reason I figured it that way is I have put marks on my translucent sprayer tank for gallons and half gallons and it is so much easier for me to measure that way.

Bill

[socalgardengal]

I will try tomorrow evening and let you know how it works.
Thank you

[Stvrob]

Please be careful spraying bleach solutions. , Atomized in the air, The concentrations that you are discussing are easily high enough to damage lung tissue.