Nematodes

[ademink]

It's like confessing you have leprosy....but I have a Morning Light w/ nematodes!!!!

I thought it was just doing the typical "melting ugly" thing but then I started thinking it thru and realized that they showed up after a LONG dry, hot period and then several days of rain. I took a leaf and did the ol' water/leaf/bright light trick and saw the horrific results.

THANK GOODNESS it is in an area of newer plants that is far away from all of my regular beds and so I haven't done any trades w/ any of the plants near it!

Ok, so on to my questions:

I have read that you need to destroy any plants w/in a 6' radius. <emoticon>

This would include:
Pee Dee Gold Flash (I've only had it two months!!!!)
Golden Prayers
Karin (gorgeous)
Striptease (an extra)
Sun Power (an extra)
Diva (noooooooooooooooooooooo)
Wide Brim (a huge, gorgeous one...believe it or not )
A 5' Guardian Angel (I just can't do it!!!!!!!)

Do I really have to destroy all of these plants????? Guardian Angel is a few feet away - pleaseohpleaseohplease say there is a chance it's clean. It's about a million eyes and I'm just sick about it!

I've read about the boil 'em like brats method but I think that isn't until until mid-winter or something, right? I can't imagine how I would even try to boil this GA.

I know I'm rambling - sorry.

What do I do now? Dig up all of the plants and pot them and put them in a little leper colony?

Also, I've read conflicting advice re: the treatment of the area where the plants are removed. Some say pour boiling water on everything and others say the nematodes are in the crown, not the soil (just to clarify, we are talking foliar nematodes here).

Please weigh in and thank you for reading my misery!

Andrea

[Chris_W]

Hi Andrea,

First, get that Morning Light out pronto and pitch it. It isn't a good enough hosta to try and salvage.

Has it been there long? Personally the only time I've seen nematodes this early is when the plants came in that same season from nurseries in a much warmer zone. Otherwise we are about 2 months away from seeing nematodes.

Next, the nematodes could live in the soil for a while. Apparently studies have shown that they can live on soil fungi if there is no host plant. So after you remove the Morning Light pour a bucket of boiling water (please be careful - steam and boiling water are dangerous) in the hole to kill any nematodes may have washed into that area. I have considered a fungicide drench to kill the soil fungus, too, although the boiling water might do the same. If there are no plants there the 10% bleach drench would work (to kill fungus, not nematodes) and is cheap - but don't let it sit on any plants nearby if you can help it.

If the plant has only been there this season it is a tough decision. Although the nematodes could splash up to 6' away, they are more likely to only go a few feet, and are most likely to splash to any other plants in direct contact.

The nematodes also are more likely to enter damaged leaves where there is an easy entrance point.

So were there any hostas directly touching the nematode infected plant? If so, consider heat treating them, and yes, you could do it right away. The longer you wait, the more the nematodes could continue moving.

I've posted the heat treatment before, but here it is again:

Get a thermometer that will accurately measure around 120 to 130 degrees. After you find a decent one check it against either a glass of ice water or a pan of boiling water. In a glass of ice water (make sure it has both ice and water for a correct reading) it should read 32 degrees. In a pan of boiling water it should read 212. You will also want some kind of timer.

Next find out the temperature of your hot tap water. You want water around 120 to 125 degrees - no hotter than 130. Turn up your hot water heater if you need it hotter. Find a faucet as close to the hot water heater as you can find so you get some good hot water. Our hot tap water is 124 degrees, so there is no need to heat water on the stove for this step.

Now get some large tubs or buckets - even large garbage cans. You will need one for the hot water and a second full of cold water. Get your water, test the temp with your thermometer, then dig up a hosta (or two or three depending on the size of the bucket) and drop them in the hot water (submerge them completely, roots, crowns, leaves). If the temp is around 120 degrees let them soak for 10 minutes. If the temp is around 130 degrees let them soak for 5 minutes. Watch the thermometer as it might drop down too much, but don't worry if it cools a little - the cooking will still happen even if it gets down near 110, just leave them in a couple extra minutes if it gets that cold. After the time is up, immediately drop them in cold water to stop the cooking process. Let them soak for quite a while so they really get a chance to cool off. If they don't cool enough the cooking process will continue and you will lose some foliage. The steam that is generated after removing the plants from the hot water does more to damage the foliage than the hot water itself.

Now get some really, really hot water and pour it in and around the old planting holes. For this use much hotter, near boiling water to REALLY make sure you've killed them in the soil around the infected plants. To be perfectly safe you would want to leave that area vacant from any hostas (or other plants) for a season, but the hot water typically does a good job of ridding that spot of any errant foliar nematodes. People who have tried this have gone years without seeing nematodes again, although it may not be completely effective.

If you have other hostas touching the infected ones you will want to heat treat those too. Plants within a few feet you might consider, but if these are new just this season the nematodes most likely haven't traveled far. But keep an eye on others nearby and heat treat as needed.

After your soil has been treated you can replant them, or move them to another spot. The hosta leaves sometimes disappear and the crowns will often come back smaller next season, but the nematodes that were in the plant will be gone. I have not lost a single plant when using this method and I've never seen the nematodes return to any of the plants in the following 3 seasons after treating.

I have tried treating Athyrium (lady ferns), Brunnera, and maidenhair ferns with this method and they did even better than the hostas. They did not shrink or loss any vigor the season after the hot water/cold water bath, even though all of the foliage was cooked on these.

Hope that helps!

Chris

[Chris_W]

By the way, nematodes really aren't the end of the world, but they do make the plants look ugly. If you are going to trade plants (secret or otherwise) you are more than likely going to get them (I can almost guarantee it). I've also received nematode infected plants from nearly every nursery I've personally purchased from, so it is really, really hard to avoid them (although I think that everyone SHOULD TRY to avoid them).

One way to prevent them from getting into the garden is to isolate new plants for a while in containers so you can watch to see if they have nematodes. By August you should know, then it is easier to heat treat or throw away, usually depending on the value of the plant. Then you can plant them into the garden. I always did this with the secret trades since nematodes are so common in gardens these days, plus we do it with all of our new incoming plants to the nursery that were not done by tissue culture.

I hope that helps.

Chris

[ademink]

This helps a LOT, thank you so much, Chris!!!

I received the plant last year. I know it had to be July or later b/c I have pics of my beds and it's not there.

I just went out and looked at the area and miraculously, it is over a foot away from any other plant! That's pretty hilarious considering the fact that most of my plants are mashed pretty closely and there is no other plant that I can think of that really isn't touching another one! It's like everyone stepped a foot away from him b/c he is infected. ha!!!

GA is over 4' away so I think it's in the clear! WHEW. The next closest one is Sun Power. Since it's an extra and not large, I think I'm just going to pitch it. Diva is equally as close so I may treat her.

I thought it seemed really odd that they were showing up now also but everything seems to be at least a month ahead of schedule w/ our crazy weather here - everything blooming early, etc.

When I did the "water test", I only actually saw about 3 nematodes in the dish (after about 20-30 minutes so it wasn't teeming w/ them. I think that ML probably had a significant amount of "melt" and that's why it looked worse. Good thing or I wouldn't have checked it for 'todes!!!!

Ok, off to dig and dispose and evaluate what gets boiled.

THANK YOU (as always ) for the fast and helpful response!!!!

Andrea

[ademink]

Just got your second post and I feel IMMENSELY better! I'm more freaked out by nematodes than HVX b/c it's so "sneaky". LOL

It seems so uncontrollable and (this is hilarious) I had a dream last night that I came outside and my entire collection had been infested and had brown streaks up the leaves! I dreamed I had to dig up and destroy everything!

I had a Fire and Ice (ironically...almost a "twin plant") last year that had nematodes. I think it actually came from a fern that I got and planted near it.

OKay, my anxiety level has reduced significantly.

Thank you!!!!!!!!!!

[baja220]

Andrea, I'm sorry about your nematodes, but could you educate us and show us pics and what's the water test?

Debbie

[Chris_W]

I'm glad I can help. And I hope that nobody thinks I am endorsing gardens with nematodes or nurseries that sell nematodes. Too many bad nurserymen have the attitude of "Oh well, you are going to get them anyway," and I do not agree with that at all. We work really hard to avoid them like the plague, but it is a lot tougher since they can move so easily on their own and because there are so many other nurseries that either don't care or they don't have the right conditions to show the damage so they may not even know and then end up sending them to us... We quarantine everything for the summer to try and catch them before they get into the growing beds, but like I said, many gift plants that went into the display garden ended up having them, so we are doing a major clear out this summer.

Keeping things far apart from each other is a really good idea, by the way. I forgot to mention that one. Plants that touch are the most likely to get them, then they will spread it to others, etc.

Some people are reporting good results using the insecticide Disulfoton on a regular basis, but this just masks the symptoms and doesn't cure the plants.

If you do get plants with nematodes from a nursery or in a trade you should let them know, just like you should with HVX. We really need to know about these things to try and put a stop to it.

[impatience]

Chris or other knowledgeable person-

Has anyone tried the peroxide method that was touted in the Hosta Journal a couple of years ago? I think I remember that some were going to try some experiements with peroxide.

I have been curious as it sure sounded easier than the hot water method.

Thanks for your responses.

[eastwood2007]

Can other problems look like nematode damage in leaves? Especially this time of year?

I just got a Sun Power from a nursery I used to work at. I have purchased a few hostas in the last three years there and have watched their inventory very closely and have never seen any problems. This SP is showing the beginnings of brown between the veins. All but one spot is where there was other damage from slugs, or whatever. Also, I know they leave their hostas out all winter, just covered, so it's not like it was in a greenhouse where they could have gotten a head start? Any ideas?

I would post a pic, but not thinking, I already cut up those leaves to put in water to look for nematodes.

[hubble]

I have a similar question to Charla's....is there anything that could look like nematodes, but not be? Could the weather or a nasty outbreak of slugs have caused some damage that could simulate the look of nematodes?

I have an 5 year old hosta that I protected from the Easter freeze that looks seriously infected. Some leaves show a vein here and there, others show damage in a fan like shape traveling up the veins from the stem, going throughout the leaf. The stems look ok. Maybe some grey spots on a few.

You may recall, I had a nematode outbreak in different garden last year, so nematode diagnosis is not unreasonable. Please tell me if it should be dug up and isolated, or let nature takes its course. It is in a grouping that I allowed to freeze and so far the rest look ok. Sorry no pics, battery is dead in the camera. Thanks.

[HostaDesigner]

I've seen nematode damage this early before at my old garden. It's been crazy-hot for us too, so any nems would show up early.

In my experience, nematode damage is very distinct. However, I've had two experiences where it looked similar, but not exactly the same. It was close enough that it made me wonder.

The first was on a Night Before Christmas seedling. It had brown stripes on the leaves between the veins, but they didn't follow the vein tightly. It's hard to describe. It was just brown coloring, not dying leaf tissue. I can post pics tonight.

The second time it happened, a slug ate all of the leaf tissue between two veins near the base of the leaf. For about 1/2 the length of the leaf, the remaining length of the vein started to turn yellow. It never completely turned brown, but it was obviously weakened.

[thehostagourmet]

You can get leaf damage from slugs or physical damage by blowing lawners discharge, fallen twigs, or any other way to put holes in the leaves. This tissue then can turn brown (bacteria or fungus) and the holes can elongate, turn brown, and eventually wither away. If this damage is only BETWEEN the veins, it can simulate nematode damage.

George

[eastwood2007]

Well, I am reasonably certain that the Sun Power has nematodes. There are 3 other leaves without damage turning brown strips between the veins. I am leaving in 15 minutes to return it to the garden center! Thank God I hadn't planted it!

I did have it in my greenhouse on the planks just inside the door. The only plant is was touching was my Jasmine that was in a pot next to. I can do the bleach drench on the floor and planks. What about my Jasmine? Is it susceptible? I only had the SP about 10 days but it was actually touching the Jasmine....

[HostaDesigner]

This is the pic I was referring to. This is the closest I've come to thinking I have nematodes. (knock on wood)

It's a genetic trait. I'm 100% sure it's not nems, believe it or not.

(clickable thumbnails)

[eastwood2007]

Hosta Designer, is that Night Before Christmas?

[LynneM]

My version of the heat treatment is to pot up the hosta (if it's a common one, I'll just pitch it), and put it in FULL sun for the rest of the year. And the next year. And then I keep it in the pot.

I still have diazanon granules from before they were banned, and I put that in the potting soil as well.

The results of my little unscientific experiment:

I have one hosta, still potted, year three now, no signs of nematodes. (vanilla creme)

I have a larger hosta, found it had nematodes late July of last year, put it in full sun last year, partial shade on my patio this year, and so far, no signs of nematodes. Course, it's probably too early. If they show up again, I'll put it back in the full sun.

[HostaDesigner]

Hosta Designer, is that Night Before Christmas?

Actually, it's an open-pollinated seedling from 'Night Before Christmas'. Pretty wild that it looks so similar.

[eastwood2007]

Hosta Designer, is that Night Before Christmas?

Actually, it's an open-pollinated seedling from 'Night Before Christmas'. Pretty wild that it looks so similar.

Hmmm....when it was first born what did it look like? Did it have streaking? Or was it marked like that from the start? Inquiring minds (newbie hybridizer) want to know...

[eastwood2007]

Well, I took the SP back to the garden center and they promptly refunded my money. In looking at their other inventory we saw a few other yellow hostas showing "nematode-like" symptoms. Night Before Christmas also showed a few. They cut sample leaves off a few they had, and off the one I returned and were going to take it to the county extension agent yesterday. They told me they had never had nematodes in their hostas, and I believe them. I mentioned previously that I used to work there (just briefly one spring) and I know that to the very best of their ability they sell nothing but the very best quality in all their perennials.

We have had alot of rain here this year, as many have, and especially alot of humidity and not yet high temps. I noticed today that I have several hostas showing leaf damage that looks unusual. Some of it looks like "nem" damage, yet in one hosta in particular I am certain there could be none as I got it from Rob Mortko. It is a TC cull off Stitch In Time, is still in a pot, and has never been exposed to 'nems'.

Some of the streaks in the leaves actually start out as a "clear" looking streak. I wonder if with all the rain, some of the thinner leaves are just drowning?

Here's keeping my fingers crossed for a positive outcome on the testing as I had the hostas in my greenhouse - in retrospect, not the best place to quarantine!

HostaDesigner, you had mentioned a genetic predisposition causing your NBC seedling to get brown streaks. Do you know what it is from?

[HostaDesigner]

HostaDesigner, you had mentioned a genetic predisposition causing your NBC seedling to get brown streaks. Do you know what it is from?

Actually, I don't. But, I have seen it in actual 'NBC's too. The brown appears only in the white centers of the leaf. The brown appears between the veins, but not tightly from edge to edge. The brown leaf tissue is healthy (i.e. not deteriorating and rotting away), and it never gets worse.