My tomatoes got wiped out in 36 hours last year, so I decided not to grow any this year---give it a rest. Unfortunately, I forgot that potatoes are susceptible to the same blight and I did plant potatoes.
There are organic fungicides, not that I have any experience with them.

I had the same blight as mentioned, last year. I also noticed some of my trees with black spots on many of the lower leaves, especially maples. This past winter was more severe for the Carolinas, and I watched for those symptoms to appear. So far, my trees look great, and my tomato plants look very strong. So, I think the blight won't be a problem this year. Maybe, it had more to do with that extended wet and cool Spring last year, especially in the NE.

The tomato blight problem of last year has nothing to do with black spots on tree leaves. Maple trees almost every year show signs of Black Tar Spot and they deal with it with no trouble and no intervention from us.
If you worked on your soil and made it into a good, healthy soil well endowed with organic matter so it is evenly moist but well drained and has a good and balanced nutrient supply for the plants growing there you should see very little problem with the tomato blight this year. While my tomatoes did eventually succumb to blight last year it was very late in the season and only after a good harvest.

If you worked on your soil and made it into a good, healthy soil well endowed with organic matter so it is evenly moist but well drained and has a good and balanced nutrient supply for the plants growing there you should see very little problem with the tomato blight this year.

I say we have a 'standard kimmmsr spam answer' contest to see how many people avoid blight this year with no measures other than good soil.

Dan

I found a few sources that may help. I note from several articles that commercial growers [who routinely use fungicides] were as devastated by the 2009 blight as were home gardeners and organic farmers.
/////
see hypertext: www.umassvegetable.org/documents/LateblightManagementforFall.pdf

scroll down to WHAT TO DO NEXT SPRING

...snip...For both crops, provide good soil fertility, water drainage, air circulation, and use cultural
practices to provide what the crop needs for healthy growth

///
For other articles google key words "Tomato blight 2009"
or key words "2010 Tomato varieties resistant to late blight"

Here is a link that might be useful: UMass Late Blight Resources & Alerts

It is amazing to me the number of people that come to an organic gardening forum and do not believe that organic methods work. Dan how can the answer I made possibly be "spam"? I sell nothing and simply offer advice based on years of study of organic gardening/farming and years of practical application of those methods.

Of course you should build your soil and healthy plants resist pests and diseases better than wimpy plants.

However, if you get hit with the blight, your soil could be straight from Eden and it won't make any difference at all.

Mulch the ground under the plants. Don't buy seedlings at disease vectoring big box stores. Consider a prophalactic use of organic fungicides if you're in a problem region.

kimmsr, there is no need to hand-wave away from your implication or try to imply that I stated something that I did not.

Anyone can scroll up and verify whether you implied, expressed indirectly, suggested that all you need to avoid blight is your standard cut-paste [nothing but good soil cures everything].

Of course good soil is key. No one is arguing otherwise. No one is saying organic methods cannot be employed. No one is stating that early/late blight can only be controlled with petrochemical pesticide. No one is stating their belief that organic methods do not work.

I am an organic gardener. I have stated this several times here when calling you on your vague spam statements as solution.

I merely offered to start a contest to see whether kimmsr's standard cut-paste is the ONLY (only, o-n-l-y, sole, exclusive, single) practice necessary to avoid, obviate, preclude, prevent, eliminate, avert the occurrence of blight.

Surely, kimmsr, you can and should enter this contest. I see last year there were some difficulties in your garden, where presumably all you did was have good soil. You can enter again with the learnings from last year and join us in the tally to see whether all you need to avoid blight (or anything else you weigh in on) is [kimmsr standard cut-paste].

-------------

To the OP, what mary said and what the text in barb's links said.

Clean ALL litter. Prune up lower leaves. Mulch. No splashing. Rotate. Plant resistant vars. Raise from clean seed. Clear refugia and all plants where spores overwinter. Help your neighbors with good cultural practices. Be vigilant, as blight can infect overnight.

Dan

I did an online search for the problem ... YIKES! While it doesn't seem to have adapted/spread to the arid southwest,I doubt I will again buy plants from a big-box nurssery department. I got the impression that ag-schools are researching for resistant varieties, and that growers/farmers/gardeners from across the spectrum of disciplines were affected. While I understand the temptation to resort to non-organic treatment regimes, it may be whistling past the graveyard - feels good, but not helpful.

Now, along the lines of improving soil health as a prophylactic ....let me suggest a few types of 'magic'. For the home gardener, I wonder if vermicompost would help to amp-up the soil health. Ditto for experimenting with beneficial soil fungi .... mycorrhizal. While claims for both of these seem to play on desperation/ambition ... I think that both should be considered along with the array of tried/true organic methods.

Here is a link that might be useful: Soil fungi

While disagreeing with another's views/methods is well within the parameters of constructive exchange/discussion, personal attacks are not productive.
A few snips from the link below seem to apply to an attack on one poster under the guise of humor. The implied "wouldn't it be fun to pile on this guy who annoys/disagrees with me/us?" is not worthy of what most on this forum hope to achieve ...namely expand our knowledge and share what we know.
////
...snip.... there are times when humor can be inappropriate and counter-productive. Humans seem to have a great capacity for turning any tool into a weapon. The same holds true in the use of humor.
...snip... In fact, what is often passed off as a joke or teasing is in reality thinly veiled hostility on the part of the "joker".
...snip... We would do well to be vigilant self-monitors of the times our wry cynicism becomes hurtful sarcasm. It is a very narrow path.

Here is a link that might be useful: Humor -use and misuse

Ilene, I had a bit of Septoria explode when I was gone during a foggy weekend and threaten my overplanted crop of cherry toms. I trimmed every infected leaf cluster and mulched and was prepared to spray household bleach diluted 10:1 (which I chose as "safer" over a Cu-based fungicide, even though the first is considered non-organic and the latter is kosher), but never needed to. I'm seeing occasional spotting but the plants are growing and producing extremely well.

If you are considering a fungicide for the soil anyway, I'd consider hydrogen peroxide at the strongest concentration you can find. It will wipe the beneficials out in the top few inches, but at least the chemical by-product is a non-issue. Late blight (phytophthora) is a far worse disease than septoria and I'd want to make sure I'd taken the best precautions I could before planting a solanum genus plant in that area again.

I grew my tomatoes from seed last year and did not see a single sign of disease. I am trying other varieties this year, also from seed, and hope not to see any blight again.

Last year's blight was devastating in our area of northeast PA. I only know of one or two gardeners who didn't experience the blight. By the time we realized what we had it was too late. We had beautiful green tomatoes rotting on the vines. I can't tell you how depressing it was. It ruined our whole gardening experience last year. All of the other things we planted to compliment the tomatoes were over abundant and we couldn't use it all. Harvest like hot peppers to make salsa ended up in the compost because we couldn't use it all or give it away.

We have a friend who owns a farm and sells produce on the retail side. He uses commercial products and had a normal harvest last year. The local cooperative extension predicted the blight and they were prepared for it. Since most of the available tomatoes were from non-organic sources we had our share of them last year.

We are hearing that there are already indications of blight in northwest PA and in Maryland. I can't imagine a repeat of last year.

We do all the right things, but if this is lingering out there we don't want it. We have considered using a commercial fungicide this year. It is very hard to break the organic regimen, but maybe one season is worth it.

A basic tenet of organic gardening is that plants growing in a good healthy soil will grow up strong and healthy and be better able to ward off attacks by insect pests and disease. There is nothing in that to imply that plants growing in an organic garden will not get diseases or be bothered by insect pests but will be less bothered by them. You will find a large number of garden writers today that tell you the same thing, make your soil good and healthy and the plants will grow up strong and healthy and better able to ward off plant diseases and insect pests.
My tomatoes did get late blight last year, late and after they produced a really good harvest. This was the first time in many years that I have seen signs of this, or any other problem, since I got sufficient amounts of organic matter in the soil and the nutrients were in balance, ie. a good, healthy soil.

I know daconil will work, but that's obviously not an organic fungicide.

There was some evidence that neem had fungicidal properties. Anyone try that? What about Serenade? Anyone? I've not tried any of the organic fungicides, relying primarily on cultural practices. Just curious about whether someone might have something to contribute on the effectiveness of either neem or serenade.

I use neem on powdery mildew to good effect.

And I had a tiny touch of blight last year where I removed the lower leaves and sprayed the stem and next leaves up and never saw it again. But this is arid Colorado so I suspect that isn't the best anecdote for back east.

Dan

No, I'm not using a fungicide and have my tomatoes planted and will just see how it all works out. We grow cover crop in the soil in raised beds, and have turned it in already. We mulch with our own chopped leaves and do our best and will leave it at that.

prairiemoon

What if your plants get Late Blight, which some have already reported a repeat of in the northeast? Maybe you don't care if your plants get it but the spores are deadly and are windborne. I think nobody else will be happy with a lassaiz-faire attitude if blight strikes again.

Yeah, Prairiemoon! How dare you not spray chlorothalonil all over your soil for a pathogen you probably don't have. It's only 600+ miles to GA from MD and no one will be happy if your nonchalant, organic attitude infects the US with phytophthora.

dicot

What's with the sarcasm?

I'd never recommend chlorothalonil as a soil spray. There ARE organic protections against late blight, and I wasn't referring to myself. You need to become aware of the devastation that late blight caused the NorthEast, not Georgia. But I'd be pretty upset if my neighbor had late blight and just was happy to let it spread all around.

Which organic products are successful? I have what I believe I septoria. Started spraying serenade but too soon to tell if it will help.
We had a very wet spring and my yard flooded from a neighborhood irrigation mishap, probably 4 times total before I could fix it. Each time tomatoes were submerged for 24. Hours or more.

Serenade (active ingredient Bacillus subtillis) won't have any effect against septoria leaf spot. If you want to stay away from synthetics, you'd have better luck with a Bordeaux mixture.

Well, if my tomato plants get blight, I will pull them and that will be the end of that. I might not end up with tomatoes, but I'm not going to poison my property, my family, myself, or the earth just to have tomatoes.

I understand that some of you think there are 'safe' organic products out there, but I'm old enough to know that when you think you are 'safe' you better think again and not take someone else's word for it. I don't have time or energy to research every possible product even if it is 'labeled' as organic, so my approach is to do as little as possible and to only commit myself to gardening practices that I sincerely believe, after my own research, to be safe.

This approach has worked for me for 25 years. That is a LONG time. I have found other ways of managing to grow a nice garden and vegetables to eat, without using any products whatsoever.

When I did a quick search on the 2009 EARLY BLIGHT problem/infestation, I can only imagine how discouraging if this happened in my garden. We in the arid southwest don't seem to have been affected.

Does soneone who has been affected want to start a new thread whose purpose will be to note which geographic areas were affected in 2009 and are affected in 2010? If held to simple reports, no opinions, that thread might prove very useful to future gardening plans and maybe even to researchers, who are missing a good resource if they don't 'mine' these forums for experiences.

BB

It's late blight that caused the devastation in the Northeast. Early blight is extremely common, and my tomatoes eventually get it most years. I just remove the affected leaves daily and have not had any plants destroyed by it. Almost everyone who grows tomatoes under hot and humid conditions gets it. I don't even spray for it if I can keep it under control that way.

I thought the 2009 Late blight epidemic was the one being discussed. If not, I've been spinning my wheels!

anney ..... Well, shut my mouth! You are correct. I could play the 'Age Card" [I'm old] But I think I'll play the "confused card" ... no kidding, I did read articles calling it an Early Blight .... but now realize that it was the LATE BLIGHT coming earlier in the season than usual.
///
...snip...So far,[7/2009] outbreaks have been sporadic but spread over a wide geographic area, with infected plants reported from South Carolina to Maine and west to Ohio.
////
Look at comments from Cornell Univ. I'm taking the meaning that organic gardeners and even farmers should not grow fruit in 2010 unless willing to use non-organic fungecides. is that your take?
http://blogs.cornell.edu/hort/2010/04/12/avoid-the-late-blight-blues/
....snip...."Anyone growing susceptible plants needs to take responsibility to ensure they dont become a Âtyphoid Mary,Â" says Meg McGrath, plant pathologist at Cornell UniversityÂs Long Island Horticulture Research and Extension Center, Riverhead, N.Y.

"We need to treat this like a community disease," she adds. "If infested, even a small garden can have a devastating impact on other plantings."
....snip....And there is potentially worse news: If both mating types of the pathogen establish here in the Northeast, they can produce thick-walled spores that overwinter and survive several years in the soil without a living host. This has already happened in parts of Scandinavia and Europe, where late blight, as a result, occurs more commonly. While only one mating type was detected in the Northeast last year, both types appear now to be established in Florida.

I'm taking the meaning that organic gardeners and even farmers should not grow fruit in 2010 unless willing to use non-organic fungecides. is that your take?

I'm not sure. It really depends on how effective organic fungicides are if one wants to prevent the fungus. Some say the organic treatments don't work. But sometimes the non-organic treatments don't work, too. It all depends on timing.

Otherwise, most of the advice seems to be what to do if your plants are already infected.

When that July 2009 report was issued, the full extent of the devastation had not yet been seen.

I do think it won't be as bad this year, simply because the convergence of two elements -- Bonnie tomatoes (thought to be the initial vector) and the terrible weather that gave the fungus an incredible boost, cold, wet, and rainy, don't seem to be on the plate this year.

But everyone I know on the tomato forum is still concerned, watching out for their own tomatoes and those of their neighbors, and keeping an eye out for official government reports.

I started a preventative spraying schedule with Neem oil (once per week, VERY dilute solution)...I'm not sure it will prevent blight, but I have been reading that it's effective on many diseases, fungi, and pests, so I figured it's worth a shot. I don't have any back up plan if the Neem fails. I have healthy soil and mulch my plants with grass clippings and shredded leaves. I am going to go all organic this year, and if my tomatoes all die, I guess lesson learned. So far they are thriving.

joellenh

Neem oil isn't a protection against Late Blight, nor should it be used as an all-round disease and pest solver. You still need to know when to use it. From Wikipedia:

Neem oil is not used for cooking purposes, but in India and Bangladesh, it is used for preparing cosmetics (soap, hair products, body hygiene creams, hand creams) and in Ayurvedic, Unani and folklore traditional medicine, in the treatment of a wide range of afflictions. The most frequently reported indications in ancient Ayurvedic writings are skin diseases, inflammations and fevers, and more recently rheumatic disorders, insect repellent and insecticide effects.[1]

Traditional Ayurvedic uses of neem include the treatment of Acne, fever, leprosy, malaria, ophthalmia and tuberculosis. Various folk remedies for neem include use as an anthelmintic, antifeedant, antiseptic, diuretic, emmenagogue, contraceptive, febrifuge, parasiticide, pediculocide and insecticide. It has been used in traditional medicine for the treatment of tetanus, urticaria, eczema, scrofula and erysipelas. Traditional routes of administration of neem extracts included oral, vaginal and topical use. Neem oil has an extensive history of human use in India and surrounding regions for a variety of therapeutic purposes. Puri (1999) has given an account of traditional uses and therapeutic indications and pharmacological studies of this oil, in his book on neem.

Formulations made of neem oil also find wide usage as a bio-pesticide for organic farming, as it repels a wide variety of pests including the mealy bug, beet armyworm, aphids, the cabbage worm, thrips, whiteflies, mites, fungus gnats, beetles, moth larvae, mushroom flies, leafminers, caterpillers, locust, nematodes and the Japanese beetle. Neem oil is not known to be harmful to mammals, birds, earthworms or some beneficial insects such as butterflies, honeybees and ladybugs. It can be used as a household pesticide for ant, bedbug, cockroach, housefly, sand fly, snail, termite and mosquitoes both as repellent and larvicide (Puri 1999). Neem oil also controls black spot, powdery mildew, anthracnose and rust (fungus).

Neem seed oil has also been found to prevent implantation and may even have an abortifacient effect similar to pennyroyal, juniper berries, wild ginger, myrrh and angelica. The effects were seen as many as ten days after fertilization in rats though it was most effective at no more than three days. (Sinha, et al., 1984); (Lal et al., 1985). In a study on rats, neem oil was given orally eight to ten days after implantation of the fetus on the uterine wall. In all cases, by day 15, the embryos were all completely resorbed by the body. The animals regained fertility on the next cycle showing no physical problems. Detailed study of the rats revealed increased levels of gamma interferon in the uterus. The neem oil enhanced the local immune response in the uterus.(Mukherjee, 1996) Post coital use of neem oil as birth control does not appear to work by hormonal changes but produces changes in the organs that make pregnancy no longer viable (Tewari, 1989) (Bardham, 1991).

Studies done when Azadirachtin (the primary active pesticidal ingredient in neem oil) was approved as a pesticide showed that when neem leaves were fed to male albino rats for 11 weeks, 100% (reversible) infertility resulted.

Neem oil and other neem products such as neem leaves and neem tea should not be consumed by pregnant women, women trying to conceive, or children. Long-term use can cause liver damage.

Neem oil is also an effective treatment for the common parasitic skin problems in pet Guinea pigs.

So, as you can see, Neem oil has its uses, but preventing Late Blight, the most destructive of funguses, isn't one of them! It does treat black spot, rust, mildew and scab, according to the label.

Sorry Anney, I think you deserved the snark for the way you called out Prariemoon. And while you seem to have a pretty strong opinion about this, you still haven't offered a concrete organic methodology for a problem that WASN'T begun by home gardeners, but rather by nurseries that sold infected plants. Sure, gardeners have a responsibility once they i.d. the pathogen, but I saw nothing in Prariemoon's initial response that deserved your implying that s/he was being inconsiderate to other tomato growers. Can we discuss organic methodologies, not personalities or non-organic solutions, now please?

Seems to me that if you suspect you have it or want to be cautious, the steps are:
1) Obsessively clean out all the solanum organic matter in the area to be planted with tomatoes and dispose of in a selaed, airtight bag;
2) Sterilize the top few inches of the soil organically; I'd suggest that strong (10%+) H2O2 or a propane flamer are the best methods. Bordeaux Mixture is fine for some, not for us with soils that are already alkaline and Cu buildup can have a lasting effects on earthworms;
3) Sterilize your seeds if germinating your own toms or purchase ones you (somehow) know to be blight-free;
4) Learn to distinguish the various tomato blights and immediately discard the plants if found to have phytophthora in a sealed, airtight bag. Treat soil in affected area immediately and again next Spring with a torch or an effective organic fungicide;
5) Don't plant tomatoes if you think you are going to contribute to spreading the disease or if you feel the need to douse the soil with chlorothalonil to get a crop.

And if you think late blight is a problem for a tomatoes, you should look into what Phytophthora ramorum is doing to the native oaks and rhododendrons of CA, where Agri-Fos and controlled burns have been the standard for a disease that is devastating our state. I do not take Phytophthora of any type lightly.

A Phytophthora caused my maternal ancestors to leave Ireland. It wasn't caused by the ornamental trade or trans-ocean shipping like chestnut blight or SOD. But it and SOD and zebra mussels are spread by careless action and inadequate care and laziness and other typical human behaviors.

Nonetheless, I fail to see where Anney advocated using a petrochemical pesticide.

Oh, wait: I also see Anney questioning the questionable lack of any preventative measures, which is simply basic common sense. And I've never lived anywhere on this planet where advocating basic common sense equates to advocating a specific chemical that was never mentioned. Nothing she wrote was controversial or advocating petrochemicals at all. Nothing. Zero. Zip. Nada.

Dan

Thought some might be interested in this 'report' from NC
I think if this blight was headed my way, I'd be outside the garden wall with a shotgun full of preventative.
////
...snip...Backyard gardeners and professional farmers are hoping late blight does not return and devastate the tomato crop like it did last year. Blight has been reported in Kentucky, Louisiana, Maryland and Florida, but not yet in North Carolina.
...snip...."There is a problem with the big-box stores that brought it in," Colucci said, adding, "If it is going to show up in North Carolina, it will be in the garden."

dicot
....you still haven't offered a concrete organic methodology for a problem that WASN'T begun by home gardeners, but rather by nurseries that sold infected plants.

Why should I "offer a concrete organic methodology" for a fungus that devastated Northeastern tomato and potato plants in 2009 and is believed there is more than a small risk for another "plague"? There are others far more knowledgeable than I who have offered treatments for this fungus, including organic farmers and gardeners, though many believe there's no organic treatment that will wipe it out. Others think the standard organic fungicides will suffice.

What I don't understand is why you'd support anybody who's willing to not even take reasonable precautions against Late Blight, and snark at me instead. If it only affected the gardens where it's found, nobody would complain, but the spores travel for miles and miles to infect the crops of others, private gardeners, commercial growers, etc. It is no longer a "personal problem" then. Would you support somebody who got a virulent disease and refused to take reasonable precautions against it and infected the public? Same principle.

I really don't understand that. It seems to be extremely self-centered.

I must have missed something here. If someone was criticizing me for something it must have gone over my head.

If anney, you are referring to me when you said 'support anybody who's not even willing to take reasonable precautions', then I have no idea what you are talking about. I think you have a nerve to state that you think anyone is being self centered and I hope that you are not referring to me.

I grew exactly 2 tomato plants last year. I did not have late blight or any other kind of blight. As a matter of fact, I had some yellowing of the lower leaves on my plants and pulled them anyway, because of all the concern there was about blight. I didn't take any chances. I had no fruit that had any problem on it. It had not been a good tomato growing season weather wise and I have only 6 hrs of sun, got my plants in late and my crop of cherry tomatoes was so small that pulling the plants was no hardship.

I did not buy plants at a box store, never have. I bought organically grown plants that are grown locally by a grower I know and were not shipped from anywhere in the country. I rarely buy plants and normally start my own from seed.

I don't believe that using a fungicide as a precaution is a reasonable suggestion and is certainly not even been shown to be effective.

If anyone has anything else to say directly to me, then address me by name and make your point, please.

pm2

I'm spraying once a week with a 30% milk spray, a teaspoon of liquid seaweed added, and a couple drops of Superthrive. There's been studies that the milk is effective as a preventative against powdery mildew, the seaweed I hope will help stimulate the plants natural immune system, and I happen to have the ST on hand so I figure it can't hurt.

I also mulched heavily with compost, over a layer of cardboard that I also put down. Hoping to avoid any splash back when watering.

And also trying corn meal, which is supposed to attract the Trichoderma fungus which is a good fungus that kills off disease causing fungi. I just spread a couple handfuls of it once a week over the growing area.

I'd be interested to hear if milk actually works against a blight. Plz report any results, buzz.

Dan

Here is an update about the 2010 tomato blight from Rodale & Organic Gardening magazine.

The recommended organic spray for late blight is copper. The prices for copper are astronomical on account of copper just costs a lot right now. Last year as usual I grew my tomatoes from seeds. Hearing about late blight, I tried an experiment with straw mulch for my big tomatoes, which is one recommended response. I had my cherries in pots. My neighbor bought his tomato plants. When the blight hit, his plants all dropped dead in a period of two days. My straw-mulched plants didn't do too well, since I was not used to using a straw mulch and didn't notice they needed water as often as I would have otherwise. They did get blight eventually, but it didn't matter much, since the lack of water seriously cut into their production. The plants in pots did okay. Eventually, they did get blight, no doubt from my neighbor's plants. The one that lived longest was Matt's Wild Cherry.

I decided that this year I would not grow any tomatoes, that I would buy them from areas of the country that aren't getting late blight, because I just had a feeling that the late blight would be back. Sure enough, it is in PA (I'm 15 mi from PA in NY, so it's just a matter of time). A friend of mine who grows a lot of his own food is growing Matt's Wild Cherry for tomatoes this year and foregoing the copper.

Good soil? My plants had very good soil. But it's soil, not a force field. When there is that much disease around, it doesn't matter how good the soil is.

my son sprinkles lime on his late blight tomatoes; every 2-3 weeks. he has also done so to the plants in my garden. however, this last year, I trimmed off the late blight branches. by growing indeterminate heirloom tomatoes, the shoots "just kept-a-comin'". that was very successful--my plants never looked like they were infected. I did notice that late blight appears to affect mainly older leaves near the root of the plant. it only affected a few areas where tomatoes were growing--there, I just trimmed the leaves as soon as they appeared affected by the blight.

in 2009, my garden was at a different house in the same neighborhood and was severely affected by late blight.

good luck gardening . . .

fungus is everywhere, bacteria is everywhere. when conditions are optimal they will be a problem. when conditions return to normal so will the infestation. if that wasn't how it works there wouldn't be any tomatoes anywhere. throwing organic methods overboard because of one years problem shows little belief and less knowledge of organic methods.