Try looking very closely at the area where you think there are eggs laid in that split part of the stem. I am not convinced it is eggs.

Tomato stalk borers (caterpillars) can bore into the stalks or stems of tomato plants, but their entry hole will be perfectly round---like a small nail hole---and the stalk borers hatch elsewhere and then bore into the stem. If you have stalk borers, they are easier to prevent than to kill after they appear. If you truly have something inside the stem, I don't know of any chemical treatment, either organic or synthetic in nature, that would kill them, that is available to the home gardener.

It is hard to tell from looking at the photo, but I think it is most likely that what you are seeing are adventitious roots, often referred to by several different names including root initials or root primordials. They are fairly common and often develop during periods of high humidity or stress. They aren't harmful----they are the plant attempting to form more roots. They commonly develop on the stalk down near the ground, but can pop up in odd places sometimes, including at the site of a plant injury/wound.

If you did have stalk borers, you would find them boring their way through the stalk of the plant similar to the way that squash vine borers work their way through stalk vines. If that were happening, your plant would be looking sad and wilty because the tunneling of a stalk borer would interfere in the way the plant's vascular system transports moisture and nutrients.

I don't know of any insect that lays eggs inside a tomato stem.

So, since I think it is likely you're seeing some adventitious roots, I've linked a photo that shows a split stem with adventitious roots forming in it. Does this look like the spot on your plant?

Dawn

Here is a link that might be useful: Image-Split Tomato Stem With Adventitious Roots

Try looking very closely at the area where you think there are eggs laid in that split part of the stem. I am not convinced it is eggs.

Tomato stalk borers (caterpillars) can bore into the stalks or stems of tomato plants, but their entry hole will be perfectly round---like a small nail hole---and the stalk borers hatch elsewhere and then bore into the stem. If you have stalk borers, they are easier to prevent than to kill after they appear. If you truly have something inside the stem, I don't know of any chemical treatment, either organic or synthetic in nature, that would kill them, that is available to the home gardener.

It is hard to tell from looking at the photo, but I think it is most likely that what you are seeing are adventitious roots, often referred to by several different names including root initials or root primordials. They are fairly common and often develop during periods of high humidity or stress. They aren't harmful----they are the plant attempting to form more roots. They commonly develop on the stalk down near the ground, but can pop up in odd places sometimes, including at the site of a plant injury/wound.

If you did have stalk borers, you would find them boring their way through the stalk of the plant similar to the way that squash vine borers work their way through stalk vines. If that were happening, your plant would be looking sad and wilty because the tunneling of a stalk borer would interfere in the way the plant's vascular system transports moisture and nutrients.

I don't know of any insect that lays eggs inside a tomato stem.

So, since I think it is likely you're seeing some adventitious roots, I've linked a photo that shows a split stem with adventitious roots forming in it. Does this look like the spot on your plant?

Dawn

Here is a link that might be useful: Image-Split Tomato Stem With Adventitious Roots

Wow, never would have guessed that! The picture does look like what I have, but the ones on mine seem more white in contrast to the green stem. Still, it seems that's probably what it is and that puts my mind at ease! I was expecting an invasion of some horrible critter that would decimate my plants!
Before I got this response I went out and sliced the...whatever they were...in half with a knife. Just didn't want anything hatching overnight and taking over! Now that I know its probably roots I'll just see it scabbed over tomorrow--I'll keep you posted! Thanks again!!!

Isn't the world of gardening amazing?

It really wasn't too hard to figure it out since there are no insects that I know of that lay their eggs inside the stalks. That pretty much left adventitious roots as the default answer.

Their color can vary a bit depending on their location on the plant and on how much direct sunlight reaches them. Often they are very white with only the slightest hint of green. Sometimes they are a darker green or even a tan color.

When I see them, I do pause a second and ask myself what the adventitious roots are trying to tell me. Usually the answer is that either their soil is very wet, the air is persistently staying very humid, or both. Often they appear on the plant when the weather is hot and humid and the plants are growing rapidly and carrying a large load of fruit. However, they also can appear when the weather has turned very dry---as if the plant knows it isn't getting enough moisture and is trying to form more roots in order to help itself. Of course, if those roots form way up on the air, they cannot root into the ground and help the plant.

If you let your plants sprawl instead of caging or staking them, adventitious roots often will root into either the ground or the mulch. You even can form a new plant by pegging a limb down to the ground so it will form adventitious roots that will root into the ground. Once it does that, you can cut that limb off from the mother plant, giving you a new small plant. You can then let it grow where it is or you can dig it up and transplant it elsewhere.

Sometimes adventitious roots start to form but don't make it very far, leaving the little roots looking more like pimples or hives than roots.

Dawn

You know, this is my first year with really vigorous going-to-take-over-my-garden tomatoes and I've wondered what those were. Last year we had just bought our house and the tomatoes were started too late to really get anywhere, Before that in Seattle I only tried to grow tomatoes in containers and I got tall, spindly plants that never produced any tomatoes...there wasn't enough sun! Glad to know what those are now! Hard to help the moisture with all the rain we've been getting, though!