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playinmud

Nematodes and my insecticidal soap concoction

playinmud
16 years ago

Last season I found that one of my beds was infested with nematodes. Many said toss them and others said heat treat them. Well, I wasn't going to toss that many hostas (25), and if I heat treated them, I had no new location to put them. So I thought heck they're worms, try homemade insecticidal soap.

So, I started last year in late August. I first went around and removed the infected leaves when they appeared, then I'd mix a batch in my Indian tank, pump it up and spray it on. This Spring I began treatments when the leaves started to unfurl. I sprayed once a week, until I ran out of ingredients, LOL - last week of June. I just bought some more and did one application two weeks ago (we've had so much rain I haven't been able to spray since).

Well, I've seen decent results. Its not 100%, but its definitely something considering everything was infected last year. Of the big ones, GE, Jewel of the Nile, Mount Tom, Five O'Clock Somewhere, and Northern Exposure, only FOS has one leaf with the tell tale brown streaking. Of the small ones, Jellybean, Blue Cadet, Corkscrew, Candy Dish, Little Miss Magic, Heart and Soul, Hart's Tongue, LS Elfin Fire, etc., only Jelly bean has a few leaves with the brown streaking. Perhaps I'm jumping the gun and its too early to tell if that's everything, but I can't help being excited at the results so far.

I use the following homemade recipe:

6 quarts of water from outside hose in Indian tank

6 Tablespoons of Dr. Bronner's Peppermint Organic Liquid Soap.

6 Tablespoons of generic mint antiseptic mouth wash (I used mint flavored)

Pump this up and spray liberally on the leaves and let run down to the crown and saturate the soil.

Who knows, maybe my persistence will pay off. I'll report back every week from now and let you know if any others start showing signs.

Donna

Comments (95)

  • hostamanfred
    16 years ago
    last modified: 9 years ago

    Donna,
    thanks for starting this thread, very informative.
    For what it's worth, I noticed 3 hostas (Oh Cindy, Inniswood & Mont. Aur. develop streaks after they got trampeled on by deer. My guess therefore is, that these monsters carry the nems around on their feet. Has anyone else have this experience?
    Manfred

  • sassy7142
    16 years ago
    last modified: 9 years ago

    When I was at Kuk's a few weeks ago we had a discussion about nematodes and he mentioned that maybe they could be carried by deer.

    If deer... than how about slugs, toads, spiders, moles or any other critter?


    Then, of course there's our own feet? We can't stick our feet in bleach water, boiling water, insecticidal soap or fungicide with each step we take!

    (still would like to know if nematodes are IN the plant or ON the plant????)


    Maybe this is why they say you can't totally get rid of them????

    sigh.....

  • playinmud
    Original Author
    16 years ago
    last modified: 9 years ago

    Sassy they are in the leaf eating the tissue (hence the necrosis/brown streaks) and outside the leaf (hence overhead watering can splash them from plant to plant). They're tiny and have a sharp end allowing them to pierce the leaf skin allowing them to enter and feed.

    On a personal note I haven't been able to spray for the past few weeks due to my dad suffering a slight heart attack/being hospitalized and then my mom going in for back surgery/being hospitalized. When I put life into perspective, nematodes are the least of my concerns.

    Donna

  • kines
    16 years ago
    last modified: 9 years ago

    I've only skimmed these latest entries, but I see concern about how easily they spread, and I want to comment. I wouldn't waste too much time worrying about how they spread.

    In the last few years of pulling affected leaves off when they show up, I have not yet seen another plant in my garden become infected. I use overheard irrigation, and I'm out stomping around in my garden quite frequently. So, in my experience, they will only spread if you really let them.

    KN

  • sassy7142
    16 years ago
    last modified: 9 years ago

    KN, That's good to hear. I do pick off affected leaves as soon as they show that all-too obvious yellowing between the veins.
    I have closely studied my gardens this year and nematodes definitely go with the flow of water.
    All my plants on higher ground are ok.
    Unfortunately, I do use overhead sprinkling, but come to think of it so does God.


    Donna, Sorry to hear about your mom & dad's health problems.
    My prayers have already been sent.
    And you take care of yourself too.
    Stress is a killer!

  • brucebanyaihsta
    16 years ago
    last modified: 9 years ago

    I have sprayed dilute bleach solution on the ground to control Southern blight and slugs, but know it is non-specific and in fact is only chemically active on soil surfaces/microbes/plants/critters that it contacts: hence a non-specific surface contact sterilizer.

    It will kill any and all organisms quickly, but it will not have any residual effect - same as ZeroTrol.

    It is somewhat similar in danger/risk to hot water: bleach, even dilute in the eye is very dangerous, depending on how much and how long you are exposed to it for.

    I did not mean to underestimate the danger: if you are not used to using bleach in laundry or other cleaning/sterilizing operations, please read the warnings on the bleach bottle.

    Please wear glasses or goggles to prevent eye injury when working with it!

    Bruce Banyai

  • sassy7142
    16 years ago
    last modified: 9 years ago

    Bruce you said;
    "If I get a "keeper" hosta that I need to rid of nematodes, I will divide it down to singles, cut out all woody tissue and leave in bleach solution overnight. Set it aside with notes that it was infected and watch it for a couple of years - repeat if necessary".

    What percentage of your hostas treated in bleach solution are nematode free the next year after treatment?

    I know doing a bleach/water treatment has to be alot less work, but in your opinion, it that procedure as effective as the heat treatment, ZeroTol or insecticidal soap treatment?

    Yes, wearing googles would be a must, but it has to be a safer alternative to carrying boiling water to the garden.

    I have a mature Gold Standard that shows new nematode damage every 4 days despite being sprayed with ZeroTol 4 times already.
    The ZeroTol just isn't working like I had hoped.
    But, I used it as the manufactor suggested and not as suggested in the article from the expert from OSU.
    (can't remember that Dr's name right now)
    Tomorrow I will spray it for the 5th time, this time using the 2% strength.
    If that doesn't do it I will then dig it up, divide it, and soak that sucker in bleach water.
    If it dies, it dies.
    I'm tired of playing with it!

    Thanks, Bruce
    Sassy

  • brucebanyaihsta
    16 years ago
    last modified: 9 years ago

    I have little faith in ZeroTrol - from the chemical ingredients it lacks what's claimed.

    I also know insecticides and heat treatments work, at some cost: the right heat treatment is quite effective (though probably can never say 100%). Insecticides work because they target the offending organism directly: you put the insecticide to work and it kills the intended target.

    Diluted bleach is the "grey" insecticide: not really as direct but effective in its own mechanism (kills anything it contacts) by rapidly oxidizing tissue. Microbes and other living cells are quite susceptible to this mechanism.

    My experience with bleaching is the nematodes don't come back to that plant, if it is effectively treated - same as heat treatment I suspect. I tend to over-do the treatment with bleach - which you can't do with heat.

    The reason many people don't use dilute bleach in garden applicatins like this is the work and hassle of using a potential skin and eye irritant: let's make sure we don't hurt the person who intends to enjoy our garden result!

    The infected Gold Standard that you have won't be impacted by Zerotrol treatment unless it hits all the nematodes in all the infected and potentially infectable tissue. Thus the best approach is to cut off all the affected leaves, any adjacent and treat in whatever method you want.

    If you want to treat it, I would cut off all leaves, dig it and the bleach the roots in cold dilute bleach solution overnight, then replant elsewhere and note it for future reference.

    You are indeed seeing late season stress which also highlights the nematode infestation.

    Bruce

  • bunnycat
    16 years ago
    last modified: 9 years ago

    I've been reading all of the posts about nematode infestations with great interest and great sadness. Some of my gardens became infected last year too. It is very depressing that nothing has been found that will totally eradicate them, and control is limited at best. Once a few plants have them, it appears that the garden itself harbors some of them even if you heat-treat or chemically treat the known sick plants.

    I've been wondering if it would be possible to keep a list of places that we have purchased infected plants, or seen them for sale. Keeping track of the variety of infected hosta would be important too. Maybe we could figure out where some of them originated from the plant tags. This would be a long-term project. We could keep list of ebay sellers, garden stores, specific big box stores (by location), mail order hosta businesses, etc.

    Some sellers may only have one bad variety. It is also possible that a plant could have been infected from "seller A" while sitting in a pot on your patio next to a hosta from "seller B." I don't know if it can happen that quickly.

    Nobody will admit to selling infected plants. As Sassy found, the garden store near her just rips off the "evidence." Maybe we could organize our own little version of "garden watchdog" for nematodes.
    I wouldn't want to run this sort of project out in the open on the hosta forum for one reason. Sellers or garden stores could feel smeared by a single accusation, and the plant from their business could have been infected after it left their hands. On the other hand, if a particular store was SEEN with obvious nematode infestations, that would be a "proof positive." Or if lots of people reported gettting their infested plants from ebay seller "XYZ", that would warrant a buyer beware warning, at the very least.

    What do you think?

    Bunnycat

  • sassy7142
    16 years ago
    last modified: 9 years ago

    Bunnycat, You have a great idea there but you'll have to count me out on helping with the "garden watchdog" for nematodes.

    I am finished with buying from any nursery around here!!!!

    Yesterday, I received a call from the plant inspector for this area, giving me an update on my complaint about nematodes found on plants at Barnes Nursery in Huron, Ohio.

    IMHO, It's a crying shame that it took a visit from the USDA to
    get that nursery to distroy plants that were obviously not healthy. IMHO, It's a crying shame that infected plants remained in the retail section after it was pointed out to the manager that their plants were infected.

    I feel bad for the people that bought all those hostas, not knowing what they were bringing into their gardens.

    I feel bad for the people that had bought and are STILL buying plants from that nursery that show no damage right now, but probably will sooner or later because the same pruning shears were used on both nematode damage plants and sun damage plants without cleaning the shears first.

    I am thankful that the plant inspector for this area is a hosta lover himself and truely does care about what is being sold out there. After talking to him for the 3rd time in the past year, it's obvious to me that it's not just a "job" for him, he really does care.

    At the end of our conversation yesterday I just came out and asked him where he buys his hostas.....HALLSON'S

    Need I tell you who'll be getting my business for now on.

    So, my days of hosta hunting around here are over.
    With nematodes at Barnes Nursery this year and HVX at Corso's in Sandusky last year....I'm giving Hallson's my business. As a matter of fact I may just run up there to Michigan in the very near future.

  • sassy7142
    16 years ago
    last modified: 9 years ago

    Bruce,
    I appreciate your opinion and knowledge.
    Tomorrow that Gold Standard of mine will be getting it's leaves wacked off, the whole plant will be dug up and soaked in a tub of 10% bleach solution overnight.
    Friday I'll plant it far away and downhill from any of the other beds.
    Thanks,
    Sassy

  • whip1 Zone 5 NE Ohio
    16 years ago
    last modified: 9 years ago

    Has anyone ever tried a shellfish fertiliser for nematode control?

    Here is a link that might be useful: crab shell fert

  • Hosta_Haven
    16 years ago
    last modified: 9 years ago

    Whip,

    That looks interesting. It would take at least one bag for most people's beds. Not that expensive though. I wonder if it might not be more effective in the south since it takes 4-8 months to take effect and works better in moist warm soil? I'd be interested to hear more if anyone has any experience in shellfish fertilizer.

    Char

  • Pieter zone 7/8 B.C.
    16 years ago
    last modified: 9 years ago

    Question for Bruce: I noticed yesterday that 3 Hosta divisions I received in a trade about a month ago show definite signs of nematode infection. They are all potted at this time, just nicely settling down, showing signs of new root growth and new shoots or leaves and are all just 2 or 3 plants per crown. I don't really want to set them back again by dividing them again into single plants, but something tells me the secret to your method is in the fresh cuts in the crown and the easy way for the bleach to start doing its stuff.

    Do you think I'll have the desired effect by bleach soaking them overnight as they are, or should I divide them into single divisions first?

    Secondly, the soil mix they're in now is best discarded, correct?

    Here is a link that might be useful: alternate posting with pictures

  • Pieter zone 7/8 B.C.
    16 years ago
    last modified: 9 years ago

    I have taken the bull by the horn, uprooted the plants, removed all infected leaves as well as those that looked suspect only, soaked them in an 8% bleach solution for 2 hours and the rest is history, as they say.

    I have detailed some of what I went through on the webpage below.

    Here is a link that might be useful: NEMATODES

  • playinmud
    Original Author
    16 years ago
    last modified: 9 years ago

    UPDATE (sorry to change the subject, just shifting back to the initial purpose of this thread...results of using homemade insecticidal soap on a nematode infested test bed).

    I haven't had free time to go spray the hosta beds these past four weeks, but wanted to report that still at this point there are no more hostas in that bed showing signs of nems (as of Sept 3rd).

    It appears that the nems have been "minimized" using the homemade insecticidal soap recipe. The thing I like about this method is that it is non-toxic, there is no digging up the plant, no dividing the plant, it does not appear to diminish the plants in any way, so to me it is a lot less work and less destructive to my landscape. I like my plants touching, and was worried about the higher rainfall spreading nems this year, but if a bed of 25 plants, where there is tremendous overlap, remains at three infected plants into September (whereas all 25 were infected last aeason), that's progress.

    Cheers,

    Donna

  • sassy7142
    16 years ago
    last modified: 9 years ago

    Donna, that is an excellent report.
    How many times did you spray this season?
    Did you add the tobacco juice to your concoction?
    Hope all is fine with your mom & dad.

  • playinmud
    Original Author
    16 years ago
    last modified: 9 years ago

    Hi Sassy,

    I started last year in late August, and sprayed once a week until the first heavy frost (it was then that I got rid of all the leaves and disposed of them...do not compost them). This Spring I began treatments when the leaves started to unfurl (early May). I sprayed once a week. Due to the constant rain and my folks' health I only sprayed once in July and once in August. In that last application in August I added the tobacco. I have no idea if that did anything, but I have to say that is one disgusting smell. I bought a cheap cigar, filled an empty gallon milk jug with warm water, stuck the cigar in that, let it sit for a few days and made a tobacco tea out of it.

    I plan on spraying again this week and continuing once a week through the first heavy frost. I may not win the war, but I feel encouraged that there is visible improvement.

    And, thank you for the well wishes for my parents Sassy, they're improving daily, the doctors are pleased at their progress. They're self-sufficient at this point and should be right as rain in no time.

    Donna

  • Hosta_Haven
    16 years ago
    last modified: 9 years ago

    Donna,

    Thank you so much for this thread and reporting your results back to us. I am going to try it! In fact, I just sprayed for the second time yesterday. While I had good results with the heat treatment, I am concerned it may be too late in the year to do it now and it is ALOT OF WORK. If I can minimize and perhaps reverse it using your far less invasive method, I much prefer it!

    Thanks again...BTW, I've added this thread to "My Favorites"!

    Char

  • sassy7142
    16 years ago
    last modified: 9 years ago

    Here's an article that I found on Hallson's website;

    If a plant becomes infected and it can be easily replaced you might want to destroy the entire plant. Spraying with Diazanon or hydrogen peroxide (1/2 cup of 3% H202 per gallon used as a foliar drench) can be effective at killing some nematodes but will not kill them all and should be repeated 2 or 3 times every 10 to 14 days. Orthene may reduce the active nematode population by about 60%, but none of these chemical treatments kill the eggs. The best way to destroy nematodes and the eggs in an infected hosta is to soak the entire plant in a warm water bath. Soak for 10 minutes in a 120F warm water bath or 5 minutes in a 130F bath. After soaking, immediately rinse with cold water to stop the cooking process.

    Here's a question for a chemist or someone alot smarter than I am.....

    I've been using ZeroTol, which is Hydrogen Dioxide..and pretty expensive.

    This article says use 3% Hydrogen Peroxide, which is what we all have in our medicine cabinets.

    Is there a difference in the two, other than the price?

    I think I can get 3% Hydrogen Peroxide (H2O2) at the dollar store for 2/$1 (1 pt bottles)

    Now...if my math is correct it would cost less than $.13 a gal diluted.

    I haven't figured out what the ZeroTol is costing me, but
    alot more than that....I'm using it at a 2% rate now.

  • playinmud
    Original Author
    16 years ago
    last modified: 9 years ago

    Char, glad you're encouraged by my experiment. Again, it hasn't been 100%, but its much, much better than it was.

    Sassy, you might consider starting another thread to ask your question. This way, perhaps we could capture the different possibilities to fight nematodes instead of burying good information in this insecticidal soap test thread. Just a suggestion. I feel bad that Bruce's info is hidden here as well, it should have been separate so everyone is aware of the benefits of minimizing nematodes with the bleach solution (which I am going to apply to another test bed next season!).

    Thanks, Donna

  • sassy7142
    16 years ago
    last modified: 9 years ago

    Ok, Donna, I'll do that.
    Sassy

  • playinmud
    Original Author
    16 years ago
    last modified: 9 years ago

    Hi all,

    Its been a week since my last update. Just wanted to relay that at this point in time only the three hostas I mentioned earlier in this thread are showing any signs of nems, and they are minimal at that.

    I have to be honest, I haven't had time to spray since mid August due to (seemingly constant) rain and family constraints. That being said, I'm pretty encouraged with these results. Even though its not 100%, its still a step in the right direction.

    Donna

  • guerrillagardens
    16 years ago
    last modified: 9 years ago

    New here. A search for treatment for nematodes brought me to this thread, but Bruce's comment about using bleach solution for southern blight really got my attention. Currently have SB in several beds, and want to know how the bleach drench works. What quantity per square foot etc? How often?
    Teresa

  • playinmud
    Original Author
    16 years ago
    last modified: 9 years ago

    Hi Teresa, great question. May I suggest that you start a new thread asking your question. Unfortunately its buried within this massive thread and many people with the same question might miss it.

    And an update, its Sept 24th and the nematodes are still limited to those three plants mentioned earlier

    Thanks, Donna

  • Pieter zone 7/8 B.C.
    16 years ago
    last modified: 9 years ago

    Seeing as this thread is being talked about on Hallson's I thought I'd give an update on my efforts, recognizing that's its still very early in the season.

    Out West the early risers are starting to break ground for me and among those are several of what I call my 'bleach babies'. For example, there is an Ice Age Trail that went from the single shoot it was went I bleached it and is now showing 4 sets of shoots, Thumbs Up is coming up, as are most of the other 'bleach babies'. So, I'll go out on a limb and say they're recovering, but, it'll be August realistically before I can say with any degree of certainty whether or not them wormz iz gone.....

  • dreamie
    16 years ago
    last modified: 9 years ago

    since my question yesterday I have been pouring over the archives and came across a "nematode" thread. What are nematode's and how do you know when you have them? So far I have only had to deal with slugs but I do have one hosta whose leaf edges tend to turn brown. Is that from nematodes or what?

  • Pieter zone 7/8 B.C.
    16 years ago
    last modified: 9 years ago

    Dreamie, welcome to the list, you'll find and gain lots of knowledge here. I could post a picture of what nem-infested Hostas look like, but I'll leave it to just post a link to my website where I talk about my discovery and experiences with these worms.

    Here is a link that might be useful: Nematodes, trials and tribulations

  • ademink
    15 years ago
    last modified: 9 years ago

    I think that nematodes have become an epidemic in the hosta kingdom and are completely unavoidable until we get some wicked chemicals again. I purchased some hostas from several *very, very* reputable sellers last year and cannot believe the amount of plants that have nematodes. WOW.

    I have some very rare plants that cannot really be replaced that also have nematodes.

    These have all been potted and in quarantine beds, etc but what fun is it to garden if you spend all of your time trying to kill insects without destroying hundreds of dollars of valuable plants?

    I think I have resigned myself to never trade again - "clean beds" or not - and plant the ugly suckers and call it a day. lol

  • Pieter zone 7/8 B.C.
    15 years ago
    last modified: 9 years ago

    Andrea, sorry to hear that on top of your personal issues you also have to deal with them thar bloody worms. And you are correct, they are quickly becoming more of scourge in the Hosta world than HVX.

    We all know that HVX has no cure and the infected plants are quickly disposed once diagnosys has been made, but part of the problem with foliar nematodes of course is that they can and do live in the soil -feeding on fungi- and that while you might have a Hosta visually clear of nematodes, they can still lurk in the soil and re-infect very easily, giving us a false sense of comfort in the meantime.

    I did end up with my nematodes as part of a trade, but I 'm fortunate that the plants in question were never planted in the ground, they were potted up. That way if there is any doubt about whether or not there is an underlying issue still with nematode presence in the planting medium it can easily get dealt with.

    No, I haven't stopped trading, but I have become much more vigilant and any new plant is kept in a pot, under cover, in quarantine for at least a year.

    As I have said above and in other posts, I'm encouraged by the seeming success of the bleach bath I subjected the infected and suspected plants in last year, but I do not harbour under any delusion of complete success until they've been clear for at least 3 years. And there's two more to go....

  • msjo
    15 years ago
    last modified: 9 years ago

    Ugh! I planted 35 varieties this year, but the only one I think may have them is my Whirlwind. I have a leaf in water right now to check in the morning. I am now "armed and dangerous" with all the suggestions here. I will do whatever it takes! Why is it that the more expensive and most traveled to get is the one?

    I also thought that maybe it was only the drought we have had lately, with all the dead leaves and such. We did get 1" of steady rain yesterday, how wonderful, finally!

  • Pieter zone 7/8 B.C.
    14 years ago
    last modified: 9 years ago

    We're now into late July 2009 and I feel an update is in order on my progress with the bleached plants. None of the surviving 'bleach-babies' have shown any signs of returning foliar nematodes. All of them were kept in standard black plastic nursery pots, mostly 1 gallon. Some have done somewhat better than others, but I suspect that boils down more to an issue with the potting mix than anything else. The pots have been kept in a covered area, on a fairly high shelf where they receive pretty much full sun. And since the area is covered there is also a fair bit of heat gain, temperatures can easily reach 90+F and with the black pots soaking up all that sun I have no doubt the soil temperature is quite a bit higher than that and I cannot help but feel that the high soil temperatures have had an impact on the foliar nematodes if there still had been any. While undoubtedly the bleach treatment is and was the first and primary line of attack, I have this suspicion the higher than average soil temperatures made an added contribution to deal with the possible recurrence of an infestation.

    I felt comfortable enough this spring to plant out one of the 'Fire Island' divisions. Others that will follow soon into the yard are 'Thumbs Up' and 'Ray Of Hope', both of which have shown great vigour. While the area these plants have been kept in was chosen primarily to keep them away from the main stock of Hosta, the heat they have endured for the past 2 years I suspect may have had more of an impact than I perhaps initially realized.

  • jakkig
    14 years ago
    last modified: 9 years ago

    Kines - your musings re nematodes have been mentioned in this post several times - I tried to get to it via the links provided, but they don't work.

    As this is such an active topic at the moment, could you please repost it - either on your website or on the forum.

    Hope I am not jumping the gun - you may have done this already - and if you have I apologize for asking you to do it again.

    Jakki

  • Janice
    14 years ago
    last modified: 9 years ago

    Kines' article is very interesting and I had copied and saved it but do not know of a link to it!

    Haven't seen our 'kines' around much so I will take the liberty of sharing what I saved!

    Here's what I have:

    Experience with foliar nematodes My personal observations: These are just my observations, and should be taken at face value. Also, this is not intended to introduce you to the problem of foliar nematodes. If you are unfamiliar with this parasite you will probably want to search elsewhere for basic information first. Only a small amount of factual information can be extracted from these observations, but it might be helpful information in some circumstances. One of the unknowns that affects many if not all of these observations: How long can a plant harbor nematodes without showing signs? I might be pessimistic, but I personally will wait at least two seasons before I decide one is clear of infestation. Native Disease Foliar nematodes are all over the place in central North Carolina, as are hostas in the garden landscape. A stroll through my neighborhood reveals that almost every sizable collection has at least one affected plant. And I believe them to be indigenous based on my discovery of a native Solomons Seal in my back yard that was heavily infested, and located in an area that made it very unlikely that I brought the nematodes to it from purchased plants. Diagnosis Diagnosis is very easy, and is described in detail elsewhere on the internet. The pattern of damage is so characteristic that after getting used to seeing it, you will have no need for direct observation of the nematodes under magnification; you can tell by simply looking at the leaf. One frequently asked question is "what am I looking for?". With a good setup, they can actually be seen with the naked eye (Im 40 years old with prescription corrected vision), but are much easier to see with a magnifying glass or jewelers loupe. In a dish of water through magnification, they look like tiny glass threads wiggling rhythmically like an earthworm. With the naked eye, the worm itself might not reach the threshold of resolution, but the evil, shimmering movement can be detected without too much trouble. Ecology Even though they spread rather easily, they are probably not quite as aggressive as one might think. First of all, when looking under magnification at a badly or even moderately affected leaf, there are hundreds, even thousands of nematodes present. I use overhead irrigation, and I have had infested plants next to others that have never shown signs of infestation, so if they very easily jumped from plant to plant, they certainly had the opportunity and failed. This reminds me of coral reef ecology, where many of the organisms living there reproduce by creating perhaps millions of offspring to have a very small number make it to reproductive age. Even if plucking leaves doesnt affect the status of the infested plant, I believe that vigilantly doing so will markedly reduce the chances of the disease spreading in your garden. I have apparently been able to halt the spread of nematodes in my garden with this practice. Boiling Soil With a caveat against drawing conclusions from experiments with only one subject: I have removed an infested hosta from its site in the landscape, poured near\-boiling water into and around the hole, then planted a young Paradise Power in the same soil as soon as it cooled (it took surprisingly long to cool off!). Three full seasons of growth later, it is a vigorous plant with no signs of infestation. The Untreated Garden I can report observations from a completely untreated garden with nematodes. My father has them in his large hosta collection, but doesnt care, and does nothing about them except occasionally pluck the ugly leaves off. The most important observation I have made is the dramatic variation in the number of affected leaves on a plant from one year to the next, and it doesnt seem to be related to heat or rainfall. One growing season where we had abundant rain was the one where his infestation was the least apparent! Perhaps the prior year is more important. Another observation is an apparent threshold that an individual plant reaches, where the infestation becomes severe and takes the plant over, and year\-to\-year variation no longer occurs. The Tiaras and other similar small, thin substance varieties seem particularly susceptible to being completely overtaken. Nematode\-Free Splits This is also a very limited experiment, but it appears that you can get a nematode\-free clump from an infested plant, as if only certain parts of the crown might be infested on a single hosta. I have two plants now that I have done this with, and the splits remain nematode free. This also implies that the nematodes might be spreading throughout a single plant the same way it spreads from one plant to another (splashing from a necrotic leaf to a healthy leaf as opposed to traveling through the crown). If true, this makes it especially important to pluck off the infested leaves before they become necrotic, even if you choose to do nothing else. Petioles and Scapes, too Heres something I can report on with great certainty: A hosta can be infested with nematodes, yet show up only with brown streaks on the petioles of the leaves. Often the leaf belonging to this petiole will go on to develop the characteristic pattern of damage, but not always. I have seen this repeatedly, especially in larger, thicker leafed varieties such as elegans and Blue Angel. This means that you might have to look very closely to know that youve got an infested plant. Furthermore, I have tested flower scapes that have brown streaks, and yup \- you guessed it nematodes! Interestingly, I have tested normal\-appearing petioles from obviously infested leaves on several occasions, and I have yet to find a nematode. Chemical Treatment Im still not ready yet to draw significant conclusions about my experiments with chemical treatments. The short answer is that there is no quick and effective cure in anything I have tried. At this time, I have three infested plants in quarantine pots, and about 5 plants in the landscape (after experiments with other plants that have now died or have been discarded). The first year of becoming aware of the problem, I started with both foliage sprays and soil granules from the local big\-box hardware stores, including triazacide and others whose names I did not document at the time, and they had no apparent effect. Most of my subsequent experiments have been with the two Bayer systemic products, one containing disulfoton, and the other containing tebuconazole and imidadoprid as the active ingredients. One thing I can tell you for sure, their use can cause stunting of the plants growth the following season. I suspect this is due to the high nitrogen content burning the roots, but I dont know. In the potted plants, I used them together in doses consistent with labeling or higher, and at more frequent intervals, in order to leave no doubt that the dose was adequate. The first year the plants and the nematodes both returned. A second year of treatment has the plants dramatically stunted, but with no nematodes so far in two out of three plants. In the landscape, I have made a similar observation. Some of the plants are showing no signs of infestation, and some have returned with nematodes, but at a dramatically reduced level. On paper this might sound promising, but my overall impression is that with the cost of the products, the effect on the mature plant size, the uncertainty of complete eradication, and unknown effect on the environment, IMHO it really isnt worth it. Except perhaps with one or two prized specimens in a collection, youll be better off discarding the infested plant and starting over with healthy plants from a reputable source. This is what I have done for the most part. Hot Tubbin' I have never tried the hot water bath (or leaving them in a car in summer with the windows up). Many others have, and have reported their experience on the Garden Web hosta forum, and the results have been mixed. It appears that the threshold for nematode death is close to that of plant cellular death (not surprising), but it apparently can be effective if done carefully. In Conclusion If you have nematodes, dont fret, you are not alone, and you shouldnt let it ruin your enthusiasm for hostas in your garden. All plants have their diseases and pitfalls, and this is just one of them. It is the way nature always has been, and always will be. I hope this article is informative and in some way encouraging. Happy Gardening! ....Kines ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ I hope this is what you were looking for!
  • kines
    14 years ago
    last modified: 9 years ago

    sorry I haven't been around much, but there have been a lot of other things consuming my time lately (all good!)...

    ...a couple of PM's have brought me back here and I'm glad that you guys re-posted the info I put up a couple of years ago. I'm looking forward to reading thru this thread and seeing what else others have come up with.

    I'm happy to report that my nematodes are still well under control, and I haven't used any toxin since the last time I posted this info (maybe 2 years ago now? - I'd have to check my records). All I do is pull off the occasional leaf I see that shows infection, and I continue to have no noticable spread in the garden.

    And good news as far as the voles go - our cat is a splendid rodent killer, and besides some occasional collateral damage in the form of shrews and birds, she has been a Godsend to the garden!

    Hope everyone is having a great summer with beautiful hostas a'plenty!

    KN

  • Janice
    14 years ago
    last modified: 9 years ago

    I realized, probably 5 mins. after posting my copy of kines observations, that I SHOULD have checked
    with the 'author' first!!! Gulp!

    My sincere apologies, kines! I was so excited that I had saved it and not having seen you around
    for a good long while, could provide it! But, you SHOULD HAVE BEEN asked, first!(still blushing)

    It really is such a good writing and I think, highly helpful! I hope we all can be encouraged by
    the work done in putting it together for us! I know that I sure feel less 'intense' about
    the whole neems thing, seeing such a good reporting from kines on this whole issue!

    Thank you, kines!

  • kines
    14 years ago
    last modified: 9 years ago

    no problem at all! I don't feel the slightest bit offended or violated or whatever, for you having saved and posted it. Just flattered, if anything. The only reason it's not on the internet still is because my ISP changed servers and I was too lazy to repost it!

    KN

  • Janice
    14 years ago
    last modified: 9 years ago

    Whew!!! :o/

  • Pieter zone 7/8 B.C.
    13 years ago
    last modified: 9 years ago

    It's time for a 2010 update of the nematode infested plants I ended up with as part of a secret trade in 2007.

    If you have read the entire thread you will know I bleached the plants I received. In none of the surviving plants -and further divisions- have I seen a recurrence of foliar nematodes. Yes, I lost some plants in 2008 and 2009, but not to the bleaching procedure. Their loss can be attributed to the use of a poorly draining potting mix, the roots and subsequently the crowns simply rotted.

    Based on my experience with using a bleach bath I would have no hesitation of using it again, should I be so unfortunate as to encounter foliar nematodes once again, be that in Hostas or other ornamentals.

    Pieter

  • bkay2000
    13 years ago
    last modified: 9 years ago

    Trying for a bump up

    bkay

  • newhostaaddict
    10 years ago
    last modified: 9 years ago

    tis that season again...

    bumping this up...

    any new treatments available ??...

    jill

  • Steve Massachusetts
    10 years ago
    last modified: 9 years ago

    The link below is from a presentation by Parwinder Grewal, one of the foremost nematologists in the US, if not the world. He is the one that is currently conducting the American Hosta Society's latest research into foliar nems. It's the best thing I've found on foliar nems.

    Steve

  • josephines167 z5 ON Canada
    10 years ago
    last modified: 9 years ago

    I just finished reading this entire post and am so glad I did! I've been using bleach ( or should I say, did use) since spring up to about June, when the hosta first emerged. However, I was using this treatment to combat slugs. It works well. i missed an area and it shows...neglect on my part, sadly..but what a difference.....no slug bite holes in treated area, lots of holes in untreated area! Little did I know I was also keeping nematodes at bay. What a relief!

    However, I do have a problem with my beautiful Whirlwind that started end of last week.. I just didnt know the problem was nematodes until now. I hate unsightly leaves and when they appeared I ripped them off. . .3 so far! I slacked off with the bleach treatment after June and Whirlwind is one casualty...hopefully one only. I will be treating the plant and area today after reading these posts.

    Thank you, All for the comprehensive information, especially "Kines's report" , Bruce's area of expertise as a chemical engineer, and "Playinmud" for posting such a valuable thread that drew out all this extremely useful information. I've earmarked it for easy reference as well.
    I'll be trying your recipe, Playinmud! :-)

    Grateful, Jo.

  • newhostaaddict
    10 years ago
    last modified: 9 years ago

    I would like to know who has declared "war" on these critters and "won" ???

    jill

  • in ny zone5
    10 years ago
    last modified: 9 years ago

    Most of my hostas have no nematodes. I just threw out one 'Rainforest Sunrise' which was a nematode magnet.

    Ha, yes I declared war on the nematodes, but only won on two hostas this year, h.'Brother Stefan' and 'Cathedral Windows', I 'cured' them using a Bayer Insecticide, others improved. Probably I should have sprayed every week, but I am never able to follow an exact schedule. Probably I got just the right timing on those hostas when I sprayed, that is when the worms were traveling possibly. You have to spray before you can see the damage. Spray perhaps every week, but that gets into too much work and then gets missed. Bernd

  • newhostaaddict
    10 years ago
    last modified: 9 years ago

    well...last week I saturated them (in the ground) with the bleach (20%ish) water bath...

    this week I used up my can of Ortho Rose Crystals (don't even have roses)...

    will think of something else to put on them next week...lol

    maybe I have to find some of that Diazinon...

    this IS war....

    jill

  • Steve Massachusetts
    10 years ago
    last modified: 9 years ago

    Jill,

    It's really not a good idea to throw ineffective chemicals one after the other at nematodes. Click on the link I placed above and learn about these critters. Use a Zero-tol regimen in the Spring or go after these guys this fall with Beneficial Nematodes called Steinernema carpocapsae.

    As for right now pull off every leaf that has chlorotic or necrotic streaks in it and throw them in the trash. Make sure you know which plants have nems, so that when you clean your garden this Fall all of the plant tissue goes in the trash. Don't leave the dead plant material on the ground and don't put it in the compost pile. Nems can live in dead plant tissue, and will over winter easily. Yes, even in Frostbite Falls, Minnesota.

    Steve

  • newhostaaddict
    10 years ago
    last modified: 9 years ago

    hi steve

    well...I could give that a try too

    these worms are toast

    jill

  • newhostaaddict
    10 years ago
    last modified: 9 years ago

    hi steve

    well...I could give that a try too

    these worms are toast

    jill