I think household bleach has sodium or potassium hydroxide, either as a leftover reagent or preservative.

Depending on the application rate it may not change the soil pH much, but it depends on how much you use.

What is making you want to 'nuke your patch'?

15 years of planting on a 35x45 patch in the front yard has led to root knot nematode, fusarium, Probably both Solani, Bacterial wilts and an organically rich fungi pile of organic matter that does things one must see to believe in the late semi tropical humid heat of an Alabama summer. I really do not care if it takes 2 years to come back at this juncture. It is faster and cheaper than building a raised bed garden by the end.

Simply because Clorox has a higher pH than you thought does not mean it will do much of anything to change the pH of that soil. While chlorine bleaches are very good sanitizers it could take several gallons to kill off those disease organisms in the soil.

Solarizing that soil may be a better option.

I have similar problems, dirtmechanic. Fusarium being the main one, in my vegetable beds. I finally decided this year to go on a concerted campaign including solarizing and long-enough rotation times. But you have me thinking that I might be able to hit it with bleach (or peroxide) as a kind of one-two punch. I'm going to look into it.

I know nothing about how much bleach would be used for this purpose, but as a chemist, I'm thinking that if you dilute the bleach in water (which is typically done when using bleach), if we knew what the original hydroxide concentration was in typical bleach + the dilution factor + application rate in gals/sq ft, it would be possible to do some estimating of the effect.

kimmq, I will not fight the summer heat this year, but like you suggest, I will make the judo move and pull the struggling plants in July and solarize that soil at that time until the temp break mid August. However, that is not now, nor does it help me across our winter, which transitionally speaking gets pretty chilly but not really freezing.

Tox, I have read about the H2O2. Giving off oxygen seems like a plan. I just worry that it is not a broad enough spectrum killer. Its not as if I believe the pathogenic crowd will stay away after a dose of clorox either, but for the maintenance side I like the idea of incorporating something like H2O2 that into the spray rotation. I am thinking that volume of clorox, as it relates to salts also. How much water to flush? 6 inches I read works for roundup type chemistry. I read a chemist say he would do it but cover the ground to prevent premature evaporation. And I forget his rate of application. It was low though; maybe a cup of clorox to a gallon of water. Still, if my patch is anywhere around 1500 square feet, and 10 inches down is the target, wowzer that seems like a big volume. I might could manage 6 inches. My tiller does not go that far down. If it was 9000 gallons of earth, roughly, then to moisten it with clorox water would mean my wife would worry about my state of mind bringing home that much clorox.

I myself would not be trying bleach application for pathogens without some kind of research-based guidance on how much to use and how to apply it. The stuff is too powerful to guess at it. JMHO.

>>but for the maintenance side I like the idea of incorporating something like H2O2 that into the spray rotation.

I suggested it as an alternative to bleach for a one-time application because it has no added lye and it also won't create salts as it reacts like bleach does. Both peroxide and bleach are very non-specific though: they will attack not only living cells but virtually any kind of organic matter. Seems to me if applied regularly, peroxide would do nothing but kill the soil food web indiscriminately and chew up some of your soil organic matter to boot. The small amount of oxygen it generates can be obtained by the soil from the air so there's no real benefit there either.

One thing about my garden is the use of home made compost really has improved the organic matter profile to the point of maybe too much. In practice, laying off the compost seems to reduce the aggressive attack. Season long natural solarization of the bare soil rather than a mulch layer also seems to reduce some fungal attacks but worsens others. The garden is in a low area, moisture is never a problem.

The blanket sterilization of the soil is a larger scale agricultural practice. I do not want to use that level of chemistry. It is mind blowing how toxic those chems are, but it works as a best practice for production. This makes me want to examine the concept but with some tweaks, like milder chemistry. I could not stop the soil web unless I went hard like the farmers do, but their inputs are massive and the machines to apply are out of reach.

If bleach is .05 sodium hypochlorite, then an 8 ounce cup has .4 oz or a little less than a half oz? Is that not 11.33 grams? Is it correct to convert 3785 grams of water in a gallon and use this 11 gram number in figuring the ratio that I read about? It seems small. 11.33% ÷ 3785g = .002% solution and I do not know if such a small amount would even do the job.

For that matter, I am not sure what is actually in the bleach either. But for preserving tomatoes in the kitchen, I have read on gardenweb where 1 tsp of bleach to a gallon is sufficient (as a vegatable wash) to ward off fungal attack for the purpose of extending shelf life of fresh picked veggies.

I have occasionally tried things that failed miserably. Perhaps testing a section rather than the whole garden and then observing is prudent. It just seems easier to do it all once I crank up the tiller.

Have you searched the web for any and all info on bleach treatment of soil?

As to the small concentration, I agree and one reason I mentioned finding some research on it is not only to avoid using too much, but to avoid using too little!

There has been considerable discussion here (see glib's posts) about what to do when you've added compost for so long that your OM, K and P are all high. Use less compost, and replace with 1) less rich mulches - think wood chips or leaves, and 2) cover crops whose roots keep the soil fluffed without adding a lot of nutrients. I have similar problems in my garden and I am paying attention to the idea that 'add compost!' may not work for the garden in perpetuity. It only works for awhile, and then the approach has to change. :-]

This is the most realistic post I found. Still, clorox is problematic. And to really confuse the issue, my property produces enough wood that one might consider the use of steam. But seriously I am not gonna lift that dirt. I might look at injection, but around here a pressure vessel in the yard is looked upon like a whiskey distillation device.

Ted Snazelle, Mississippi

June 3, 2011 at 5:53 am

Friends,

Basamid is extremely volatile and dangerous to work with. I had a large bag of it at the college. Recently, I had our laboratory safety person make a proper disposal of it, i.e. a dangerous chemical disposal company picked it for disposal.

I was trained as a plant pathologist in the era of chemical control. Looking back on some of the nasty chemicals I have been exposed to, it sometimes seems to me that it is a miracle that I am alive. Thus, I am now exceedlingly cautious about using any chemical as a biocide, i.e. I don’t want to personally experience the cidal (killing) effect!

In the case of trying to sterilizie a small garden area to rid it of the basal rot fungus, I see no harm in saturating a small area with chlorox (6% sodium hypochlorite) to try to kill the basal rot fungus. However, I would cover it with a plastic to slow the release of the chlorine from the soil. Leave the plastic on as long as the soil remains moist, particularly if the location is sunny (then you might also benefit from solarization). How well this will work in ridding the basal rot fungus from the soil, I don’t know. Nonetheless, I know from first hand experience, under laboratory conditions, chlorox is an effective fungicide.

This year, as in past years, I have used a hose to throughly wash off all the soil, etc. I can from the lifted bulbs. This year, for the first time, I dipped the washed bulbs for 15 minutes in 1% sodium hypochlorite (1 part chlorox to 5 parts water) or 0.5% sodium hypochlorite (1/2 part chlorox to 51/2 parts water). Then, I placed the bags of dipped bulbs on racks to dry. The next day, I hung the bulbs from the rafters of the utility building/carport behind my house. The building is well-ventilated and the bulbs cure out there very nicely.

Ted

Theodore E. Snazelle, Ph.D.

101 Water Oaks Drive

Clinton MS 39056-9733

I just do not think I can go this strong. I think I am going to use sugar and thyme oil, and then solarize this summer. Then, next year maybe, re evaluate.

You can always try a limited area, big enough to get the temp up in solarization but small enough you can try different methods and see what works best.