Brown Stem on Tomato

[brownrexx]

I have never had a problem like this before with my tomatoes. I grew them all from seed and everything looked nice and healthy when I planted them in the garden about 3 weeks ago.

I noticed that one of my Rebel Yell was wilting and I discovered that the stem just at and below ground level had become brown, dry and hard. I cut the plant off just above the brown part and the stem looks green and healthy inside so I put it into a jar of water to root but what caused this?

Tonight I discovered the same thing on a Fox Cherry plant and a Black cherry plant and I cut them off and placed them into water also.

I have a theory but I would like your opinions. My theory is that after I planted the seedlings we had terrible winds and the plants were blown back and forth. They were not staked and were not big enough to be supported by the tomato cages. I think that possibly the stems got damaged by blowing back and forth and that pathogens invaded

I have never had this problem ever before. What are your thoughts?

20200608_195551 by Brownrexx, on Flickr

20200608_195457 by Brownrexx, on Flickr

20200608_195407 by Brownrexx, on Flickr

[EdieJ]

Could something have chewed on them?

[pepperhead212]

Sorry to hear that,[mention]brownrexx[/mention]. I hope that they root for you. You probably don't have any cloning liquid, but if you have some rooting powder, you could dissolve some in the water, to help it speed up.

It's quite possible the wind caused the damage, but it seems that the plants would have been much weaker (not really strong enough to root) before the browned stems looked so bad. But I'm just guessing.

[MsCowpea]

I don’t know if your straw mulch ever touches the stem or not. We get stem rot like that when I used to let straw or grass mulch touch the stems. Even if we applied the straw inches away from the stem watering would shove the mulch over to the plant. And it wouldn’t take much to damage it.
If you google straw mulch on tomatoes they always advise to keep it away from stem or you can get fungal problems.
I see pictures online where people use straw apparently without any issues but that wasn’t the case with us.

I use plastic edging, modified so that I can connect it into a triangle to keep the mulch away as I sometimes use heavy straw recommended by Charles Wilber. (3 to 4 inches thick). We Use them even without mulch has it protects small plants from soil splash up when somebody waters them too hard.
Once we did this never had one rotted stem ever again.


Small mini raised bed open to the ground. With plastic triangle guard.

8CE84BD8-818C-40C0-9866-0639B8E34CEB.jpeg

[Mark_Thompson]

I don’t know if your straw mulch ever touches the stem or not. We get stem rot like that when I used to let straw or grass mulch touch the stems. Even if we applied the straw inches away from the stem watering would shove the mulch over to the plant. And it wouldn’t take much to damage it.
If you google straw mulch on tomatoes they always advise to keep it away from stem or you can get fungal problems.
I see pictures online where people use straw apparently without any issues but that wasn’t the case with us.

I second this. Lost a few really nice plants before I wised up.

[brownrexx]

This sounds reasonable but I have been using straw mulch for years and have never had a problem. I don't have as much rain as either FL or Hawaii so I am wondering if this could be the difference. The brown area is not like a soft rot either. It is hard and brittle.

[GoDawgs]

I searched through a lot of tomato disease and problem sites last night and couldn't find anything that really matched what you have, especially that hard, brittle thing that's going on. Extension Service time?

[pepperhead212]

If straw is causing this problem, how is it that a lot of tomatoes are grown in straw bales? I haven't heard about this problem from those
growing in the bales.

[MsCowpea]

I know that is a contradiction. I started to mention the straw bale growing method but edited it out. I know people grow in straw bales where a small amount of potting soil is added first ,and like others who mulch with straw, have no problems.
I tried the straw bale method myself but it wasn’t something I would ever repeat for a number of reasons. I just found I just can’t let grass clippings or the straw mulch touch the stems without asking for problems like that rot.
But others may not have that experience.

Found this online:
https://homeguides.sfgate.com/use-hay-m ... 21504.html

“Arrange the hay so it does not touch the stems or leaves of your tomatoes since this can increase the likelihood of fungal problems transferring from the soil to your tomato.”

[Ginger2778]

I don’t know if your straw mulch ever touches the stem or not. We get stem rot like that when I used to let straw or grass mulch touch the stems. Even if we applied the straw inches away from the stem watering would shove the mulch over to the plant. And it wouldn’t take much to damage it.
If you google straw mulch on tomatoes they always advise to keep it away from stem or you can get fungal problems.
I see pictures online where people use straw apparently without any issues but that wasn’t the case with us.

I use plastic edging, modified so that I can connect it into a triangle to keep the mulch away as I sometimes use heavy straw recommended by Charles Wilber. (3 to 4 inches thick). We Use them even without mulch has it protects small plants from soil splash up when somebody waters them too hard.
Once we did this never had one rotted stem ever again.


Small mini raised bed open to the ground. With plastic triangle guard.
8CE84BD8-818C-40C0-9866-0639B8E34CEB.jpeg

Correct diagnosis by Ms.Cowpea, and great advice. Please follow it, she told you exactly what you should do.
The common name for this is "damping off."

[MsCowpea]

I noticed when ‘ arnorrian’ posted his/her wonderful garden pics that straw mulch was used and I thought to myself - wonder why I have such problems if I don’t keep it away from the stem and others do not. Maybe it is just a perfect storm of several conditions (like the damping off pathogens Marsha mentions) that make it a problem
or not a problem.

(Amended: the damping off pathogens Marsha mentions and the overly moist conditions created by straw/grass mulch that are touching the stem. Other possible factors: poor drainage along with too much water.)

[brownrexx]

I have never, ever had damping off either indoors or outdoors but I Googled photos and some of them DO look like my plant stems where they get real skinny and hard just below the soil surface.

Now I have had one bell pepper plant die too.

Do you really think that it could be damping off in plants that are large and flowering? They have been in the ground for 3 weeks.

I read that mature plants are rarely affected because the stems are strong enough to withstand it. If you really think that this looks like damping off then I suspect that I was correct that the days of wind blowing the plants back and forth probably caused small injuries in the stems and allowed the fungus to enter.

What do you think?

Thanks.

[Ginger2778]

I have never, ever had damping off either indoors or outdoors but I Googled photos and some of them DO look like my plant stems where they get real skinny and hard just below the soil surface.

Now I have had one bell pepper plant die too.

Do you really think that it could be damping off in plants that are large and flowering? They have been in the ground for 3 weeks.

I read that mature plants are rarely affected because the stems are strong enough to withstand it. If you really think that this looks like damping off then I suspect that I was correct that the days of wind blowing the plants back and forth probably caused small injuries in the stems and allowed the fungus to enter.

What do you think?

Thanks.

I am quite sure it's damping off. It's not as rare as you might think.

[brownrexx]

Thank you [mention]Ginger2778[/mention] I hope I do not lose all 17 of my plants.

[bower]

I had something similar turn up on a couple of plants before transplant. More of a lighter brown color but as we know, it aughta be green! I am thinking it is something to do with the old seed, since they are all same variety, could be something seedborne.
So I was really glad I noticed it before they got planted.

[brownrexx]

I went out and inspected the stems of all of my remaining plants and it looks like I may have about 8 out of 17 that are unaffected. 2 out of 3 of my Big Beef have the skinny, hard stems below ground so I am going to replace them since the local greenhouse still has large seedlings. I think that it's probably better to just rip them out and replace them instead of trying to nurse them and have them die anyway.

3 more bell peppers seem affected too so I will replace them.

I pulled the straw back from all stems of all plants and watered them all well so now we wait and see.

[mention]MissS[/mention] I grew 2 Rebel Yell from your seeds and it's a good thing because one had the damping off problem and the other one didn't. I cut the one with the bad stem off and put it into a jar of water to grow roots. I really wanted to try this variety so I am happy that at least one survived.

[mention]Paulf[/mention] you mulch your tomatoes like I do with straw. Have you ever seen this problem with your plants?

[pepperhead212]

I never thought about damping off, except with seedlings, but that makes sense. Sorry to hear about that, [mention]brownrexx[/mention]. If that is something that is spreading out there, something you might want to try is some micorrhyzae - something I use for just about everything, indoors and out. I have read that this helps prevent soil borne fungal diseases, as well as others. I also heard that the biochar helps prevent these.

[Sue_CT]

I posted earlier, hope I didn't post under the wrong topic because I don't see it now. I have been using a heat treated hay product for years without a problem. Doesn't seem like it could be heated too much consiering the combustibility of dry hay, lol, but maybe it helps and that is why I haven't had any problems. I don't put it right up against the stem, but I am not OCD about it either. My conditions are almost as far as you can get from Ginger2778, so I don't think we can really compare our results. Since you have already pulled it back, hopefully your remaining plants do fine.

[brownrexx]

I never considered damping off either [mention]pepperhead212[/mention] but that seems to be the diagnosis. I had one plant wilt and die last year for no apparent reason and I'll bet that it was the same thing but I never figured it out. I removed the soil from the hole and discarded it and then and planted a new seedling in the same hole and it was fine.

Mature plants are supposed to be able to resist the damping off fungus because their stems are thicker than delicate seedlings but I'll bet that the severe wind whipping my plants back and forth caused small injuries to the stems and the damping off fungus was able to move in. Supposedly it naturally lives in the soil.

I will have to check into micorrhyzae.

[MsCowpea]

“Fungi that cause damping-off occur in all soils where tomatoes are grown and they infect tomatoes when the soil is wet. “
(UCANR)