I'm no soil scientist but I suspect that chlorine bleach would be safe as far as it being gone by spring....or even sooner. A couple possibilities come to mind that are negative. It might take a whole lot of bleach and and some friendly critters could be killed also.

I'd use hydrogen peroxide.

Here is a link that might be useful: Hydrogen peroxide in the garden

I would be afraid of harming the soil with bleach solution. Even though I am not an organic gardening zealot, I believe micro-organisms are necessary for a "healthy" soil. There is no question that bleach will kill most micro-organisms, both good and bad.

Jim

I wouldn't use bleach, I'd drench the soil with 20% vinegar.

We had a swimming pool that was treated with chlorine, and it drained into a flower/shrub bed and onto the lawn. The plants and the grass were in excellent health for all the years we were there, so I can't see that it would hurt anything if properly diluted. Just my opinion, not based on science.

Here is a link that might be useful: Annie's Kitchen Garden

Bleach decomposes instantly when it comes in contact with soil organic matter. It won't work don't waste your money. On my farm I used to use fumigants, they will kill disease in the soil but only temporally. Nature hates a vacuum and the diseases return. If you can rotate your garden to a new spot every three years that will solve most of the problems... Bob.

I like the idea of controled burning at the end of the garden season .Bleach and hydrogen peroxide do return to original state (harmless water)within several hours. I have poured bleach on weeds against the house and nothing seemed to ever grow there again .

-researchers found that injecting salt water with electrical current broke down the salt (sodium chloride) molecules and produced a compound called sodium hypochlorite. This discovery enabled the mass production of sodium hypochlorite, or chlorine, bleach.

Thanks to all who have responded to my question. I'm impressed with all the answers given. Maybe my friend isn't crazy after all. I would never have thought of controling diseases in the soil this way, but if that is what she wants to do I guess that is up to her. I will give her some of your suggestions, maybe she'll use one of them instead of the bleach. Thanks to all who have responded, I really appreciate your help and insite....Lisa

I am very interested in sterilizing the soil in my vegetable garden. I had trouble with fusarium wilt killing three of my tomatoes--Amelia, Cupid, and--though it took a long time--Heat Wave.

I have a Better Boy growing next to the Amelia and it was never affected at all. And both, according to Park's Seed Catalog, are resistant only to race 1 of fusarium wilt. So why was my Better Boy spared? They were less than 3 feet apart.

I wonder if watering the garden with hydrogen peroxide with one of those hose sprayers would kill the fungus? It seems to me, it wouldn't go deep enough into the soil.

What about Vapam? It is a soil fumigant. I used it once, over 20 years ago, and it really worked and the garden could be planted a month after application. But it sounds pretty poisonous and I don't even know where to get it. I haven't seen it in years.

My garden is 12' by 12' and so I can't rotate it. I can put the tomatoes in another part of the garden, but it does get some shade and I had to put the tomatoes where they would get the most sun. I also grew cucumbers and green beans, which all did quite well.

Any thoughts?

I'd be more apt to examine the gardening practises before I'd start dumping gallons of bleach on the ground. A better use for the bleach would be to disinfect all your stakes, cages and garden tools that you're using. Use mulch on the ground to keep the early blight contained on the ground instead of splashing up on the plants. For the fusarium wilt, try Mycostop, it's an approved organic spray.

Seeds can also come contaminated too, so maybe that is a source?

I think if you're interested in "sanitizing" your soil, using a propane weed torch to systemically burn the garden would be a better way to do it, and probably would result in better sanitizing than bleach solutions would. I don't understand the point of growing your own if you're going to dump bleach in the ground, your soil is the most crucial part of your garden and temporarily sanitizing things won't stop re-infection from occurring if it's source is cultural practices in your garden.

Weeding is crucial in controlling plant diseases as well, various weeds are hosts for all sorts of things.

When I sterilize my carboys prior to brewing beer, I place a couple tbsp bleach and a gallon of water in each carboy, swish it up and down the carboy, and dump it on my patio. As the solution trickles over the edge of the patio and into the lawn, earthworms come out writhing like mad, clearly in extreme distress. And it is a fairly dilute solution. I have no doubt that bleach will kill the entire garden micro-fauna.

I would not consider growing tomatoes without mulching them thickly with wood chips. It saves water, weeding, and minimizes early blight. Crop rotation should do the rest, though I understand that in small gardens it is not always possible. There is also a broad spectrum of resistance to early blight. In my experience, Yellow Pear, Stupice and Early Girl do very well, Brandywine and san Marzano a bit less so, but they still produce, and Costoluto and Jubilee (an orange tomato) do very poorly.

I'd be very leery of trying to sterilize your garden with bleach. To get the diseases you are after, you would probably have to thoroughly soak the soil. When the bleach goes into the soil, it begins degrading the organic matter that it contacts, all the humus, all the micro-organisms, etc, so I would expect it would take quite a large quantity to remove all the disease organisms to whatever depth they go down to--maybe a foot.

Doing this would have a couple negative effects--first, the sodium hypochlorite will break down into salt and with large quantities you will be salting out your soil and damaging its structure. At some point, the salt will have to be eliminated or little may grow. Secondly, removing the pathogens will also remove many of the billions of good bugs in the soil and reduce its health in other ways. Might as well bake the soil in the oven. It will sterilize it just as well or better, but won't destroy all the organic matter and won't salt the ground out.

Much better to go after it in other ways. Eliminate any diseased foliage from the garden immediately. Remove all host plants at the end of the season to reduce the residue for the pathogens to survive on. Use mulches to prevent rain splash from infecting leaves. Plant resistant varieties. Look for other controls, "organic", chemical, or other. Move your susceptible plants to different locations in the garden each year, or move susceptible plants and hosts out of the garden for several years (hide the tomatoes here and there in the flower beds).

Several years ago I noticed increasing problems with blight in tomatoes. At the time, I was adding large quantities of well rotted manure to the soil. Decided that the manure might be helping to host the blight in the soil or at least giving it a favorable environment, so backed off considerably in how much I apply. The blight problems dropped off considerably.

The health department nurse in our county said that bleach degrades into toxic byproducts.

If your diseases are entrenched in your soil - the only thing I was told you could do was to add large quantities of compost and over dress with cut grass, leaves, etc. Then don't plant anything that these diseases will attack for two years. My local organic gardening guru from the large nursery where I shop told me this. He said to plant my other affected plants in containers and to keep them as far away as possible from the affected area. He said the compost and breaking down of the organic materials would in time, kill the disease. ?!?! TiMo

clasher, if you read this would you please tell me if this is the type of torch you are talking about?
TIA

Here is a link that might be useful: propane weed torch

michael357's grafting suggestion is a pretty good one if you have a basic understanding of grafting (it doesn't take much of an understanding) and a proper after-care environment for your grafted seedlings.

There's plenty of good disease resistant root stock and an approach graft on a herbaceous plant is a lot easier than it sounds/looks.

There is no instant-soil-fix out there that I know of besides a soil fumigation (and instant+fumigation isn't as easy as putting something somewhere, turning a knob, and walking away). As mentioned above, this is not a permanent solution.

Love all the innovative comments. My first thought was bleach....seemed to drastic....so here I am.

I 'had' two Shasta Daisies' that came down with a BACTERIAL INFECTION. This scared me....I do not want my entire gardens infected. The nursery finally identified it as a bacteria...which basically rests on the stock of the plant, denying it water, sapping it of nutrition. Like a cancer or virus in humans. We looked at it under a micrscope...creepy....all kinds of nasties. I dug them both out and have allowed the soil to go fallow. Going to let the winter freeze kill anything else. But was still thIinking about bleach for that small issue. Then wretch out all potentially contaminated soil. If i just spray it? Not going to pour a gallon. What think you?

Secondly, my neighbors lilac bushes are taking over my yard and tearing down my fence.... Love the previous comment on taking a blow torch, so natural. Then was considering the comment on Vapalm, lol. I have much domestic & wildlife, flowers and herbs here. I will do what is environmentally safe, but I do have those moments.

No real conclusions? What my first thoughts are....going to dig down to root level all along the fence (God help me), poison it with something stringent but keep it tarped with plastic over the winter. What think you?

You kill bacteria in one bed with bleach, it will ALL come back from the adjacent beds you didn't bleach. This stuff is airborne. But you'd have to drench the bed with bleach even to do that. You spray the surface, and what about the stuff an inch down? Winter freeze kills? Nope, not stuff buried in the soil. It may be freezing on the surface, but it isn't underground. In fact, a freeze just puts most bacteria in a dormant state. Doesn't kill 'em.

I would just chill.

P.S. Vapam was banned for residential use around the time that this ancient thread originated.