Peach-tree Borers!

I must have borers chomping at the base of my O’Henry peach tree (on Lovell rootstock). The tree is growing vigorous lush foliage and otherwise looks healthy. But for a few weeks, it’s been oozing orange gel at the bottom of the trunk. Pretty certain it’s borers and not the similar symptoms of cytospora canker gummosis. I’ve taken a quick look at the literature and photos online. But I want to hear from you all:

What are your experiences with peach-tree borers? Is this a death sentence for my O’Henry? Have you found effective tricks to get rid of these nasty critters? (Preferably organic. I’d hate to start with the insecticides if I can avoid it). Has anyone tried using beneficial nematodes?

Please share your wisdom… ready, set, go!

You have to go after the “worms” with a thin knife or a wire ASAP. The damaged cambium will be easy to find and dead bark can be removed without further damaging the tree while you search out the small tunnels and kill the invaders. They also sometimes aggregate on the outside.

They kill only when they completely girdle the trunk and it can be 3/4’s girdled without losing much vigor.

Organic seems irrational to me when you are only talking about spraying such a small area. In a few more years you will likely become a bit more sanguine about using some affective synthetics if it is the difference between success and failure.

There are quite a few organic apple orchards in NYS, but none of them offer stone fruit that I know about.

My small peach tree had borers last year, I got in it with a paperclip and now it’s fine. I had a 2nd leaf plum I left a plastic tree wrap on too late this spring and they demolished it.

Did you whitewash your trees?

I had it on myPF 24 C when it was a 2-3 yrs old tree. I used a clothes hanger wire. Cut it out. Poke the hole until I thought anything in there would be pierced to death.

I’ve used moth balls mounded with dirt around the trunk. I know some people poo poo it but it does not bother me one way or the other.

For the past 3-4 years, I’ve sprayed Triazicide on the trees. I’ve told it works with borers, too.

I’ve not had any borers since. It’s probably because of Triazicide, not the moth balls. Anyway, this year, I have not sprayed any Triazicide yet. If I see borer sign, I may use it only on the trunks and ground around them. I try to go mostly organic on the fruit this year.

Are you absolutely sure that it’s borers? Do you see frass and do you see borers, when you probe the tree? If you don’t, then you don’t have borers. If you’ve been getting lots of rain, as most of us have, the tree is under stress from too much rain, and is oozing sap as a release mechanism from the excess rain. I’ve had this happen all last week to some of my peaches, plums and pluots, but can find no borers, and if you can’t find actual borers, that’s what’s happening to your trees.

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If its only oozing from the base it sounds more like borers to me. But the main sign its truly borers is there will be brownish-tan sawdust-ooze stuff. Its like you mixed 50-50 sawdust with the clear goo that oozes from peach trees. Dig around the base to see if you have any of that.

I have tried many treatments. My current one which seems that it might actually work is I paint the lower few inches of trunk and underground with raw neem (not spray, the non-diluted oil). The trees don’t seem to mind and I have not seen a single borer this year after I applied the neem over the winter.


Scott, do you recommend any brand or any site to buy, please?


Interesting. I have some neem (the pure stuff off ebay) on hand… maybe i’ll try that. I have them pretty bad here. I killed many late this winter by digging around the base of the trees. Once you find a couple, you know what to look for. Some are tough to kill. My trees all leafed out just fine, so i must have done something right.

Are we a little early yet up here? I thought July was the month that the fly/lay eggs?

Thanks everyone for sharing your advice.

Yes. I did whitewash the base of the tree last year per the video instructions of former DWN FruitTube star, Ed Laivo.

Here’s a pic of the subject tree taken last week:

I visited the tree yesterday, but forgot to snap a new pic. Yesterday, conditions looked way worse. Lots more orange jello at the base of the tree.

The pure neem - dormant application?

I forgot, the peach tree borer egg is laid outside of the tree. The larvae can burrow in the soil and enter below the soil line where there most likely isn’t any paint. Whitewash is probably more effective at blocking other types of adult borers that deposit eggs directly under the bark. Even then, some claim that a pyrethroid needs to be added to the whitewash for complete effectiveness.

I tried neem on mine, neat, injected into the hoIes. Borers died but it didn’t save my trees :frowning: due to damage from the borers

I manage so many orchards spread out so far but almost never lose a tree to borers. Some of that is due to the magic of modern chemistry but trees do get hit and I’m not all that thorough.

It takes a lot to kill a really vigorous peach tree. When trees are establishing it is helpful to push them with ample N, no matter the source. If soil is well drained it is not hard to get peach trees to grow at a rate of vigor that takes most of the existential threat out of borers, IME.

That does look like a borer to me Matt.

@Brethil, I did a dormant application of neem in the winter.

@alan, I have lost quite a few peach trees to borers. They may do more damage in our longer seasons, and I was doing no spray on them for several years. If an adult tree first sees borers at that point it might not have much problem.

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Scrape away all of the goo and do a diligent search for borers. If you don’t find any, then you don’t have borers. You have what I stated. If you do find borers, you must dig them out or they can do serious damage to your tree.

Ray, I don’t think not finding borers means much, they can go deep and where you are not looking. But if you don’t find any freshly dug holes its not borers. The main blob there looks like it has sawdust in it. The little shiny blob on the left looks like pure goo, if it only looked like that little blob I would not be worried.

I’ve had just one tree attacked by borers. That was 5 years ago and although still living and even growing it is a very sickly specimen. That borer attack precipitated a rapid decline that it has never recovered from. I have no idea why.
My one time experience with them leaves me feeling as though they make the Devil look like the Easter bunny.

Scott, that’s why I used the word diligent. You have to probe for them. You’re seeing more in the picture
than I do, because I don’t see any frass. All I see is goo. Matt needs to scrape away the goo to find
out for sure. If it was my tree, I wouldn’t ignore the situation.

Scott, that is a good point. It is still bound to be helpful to keep the trees as vigorous as possible while they are establishing.

Do you lose mature trees to borers?