Hey all, I’ve been weeding my apples and have seen what looks like borer damage on the rootstocks. I suspect borers because of bright orange ‘frass’ near the base of the tree, and some tiny holes.
I’ve searched the site on how to prevent/control apple borers but haven’t seen anything definitive, other than painting the trunk, and poking a wire into the holes to kill any critters that may be in there.
So, if I do have borers, what’s the best way to control them and prevent further attacks? I lost a tree this year during a windstorm, but it had been damaged by borers and/or rodents enough so that it wasn’t strong enough to withstand the wind. So any info would be a big help.
If you go natural a mix of SF, HB and SC nematodes are effective but you would probably have to buy a 50 million pack for a pretty small amount of your trees and they will kill the next generation of borers (infecting the current ones) and bad nematodes, The hard thing with natural predators is you need to get them high enough for a pest equilibrium, you need to apply them with a sprayer that has not had any pesticides in it, otherwise you could mix them with water into a slurry and water it in, in most environments they offer long term control and atleast make the issue better although they migrate with the infected bugs around so you may need to reintroduce them yearly for pests like fleas as the fleas can get started before the nematodes (SC nematodes for fleas) . The cool thing is these nematodes also affect CM (although you would need to treat miles to get control) and PC as well as fleas and numerous bad nematodes. Beneficial nematodes are also useful in controlling the spread of many parasites.
If you use any hardcore soil or systemic pesticides you most likely kill these off and imidacloriprid has been demonstrated to stop your plants ability to communicate with beneficial nematodes underground.
Do you have any research to support the efficacy of using nematodes to control apple borers? That would be something extremely difficult to draw evidence from anecdotal observation, at least in my neck of the woods, because the borers strike very randomly in my orchard- nursery and the orchards I manage. They aren’t a huge problem, actually.
Does wood ash help? I have an uncle who has peach trees and borers were a big problem. He “heard” somewhere it would control them. He put a foot wide ring right up to the base of the tree, an inch or so deep. No problems since. I’ve not had problems yet with my young peach trees but am starting to do the same in hopes it will help. Am wondering if the same ‘remedy’ would work for Apples?
Thanks for the suggestions. I had read in some posts by @scottfsmith about using a neem oil paste for peach trees, but I’m not sure about what’s in it. Would that work with apple trees as well? Maybe he could comment?
I’m pretty sure it’s borers, as I mentioned, I see bright orange frass (looks like sawdust) near the ground, and holes in the cloth wrap I had put around the base of the tree to deter rodent damage and sunscald. I have seen this on quite a few of my trees, so I’d like to get it under control. As I mentioned, I had a tree get snapped off at the ground by high winds that had been weakened by borers and rodents.
A different tree hasn’t leafed out this spring, so I assume it’s dead, but I haven’t figured out what caused its demise. Plus, my biggest tree bloomed but those blossoms got fried by last month’s freeze, but now it hasn’t leafed out hardly at all. It did this last year, so I might end up losing it too.
I still think the prevention would be similar. For non-organic approach, people spray triazicide to kill other borers, I would think it would work. First thing first, dig out those borers with clothes hanger wire.
Thanks. I don’t know what’s the cause yet, but due to the sawdust and holes in the rootstocks, I assume they’re some kind of borer. I should consult my UK ag publications to be sure.
I haven’t had a borer yet (knock wood) but I remember seeing some advice that sounded good from Apples – Ames
“Control trunk borers—they can kill trees, especially drought-stressed trees. Wrapping trunks with window screen is about 90% effective. I inspect twice/year (April and August) and carefully remove any borers with a knife and a piece of wire. During the April inspection, I spray beneficial nematodes into active tunnels and also around the base of trees.”
Not sure how much screen it would take but depending on how many trees you have it might be worth it.
Bob, I’ve used Fedco/Bunker’s alternate formula anti-borer paint for ten years now with success (no borers). And we certainly have them; I lost many young trees to borers before then. I substituted what I had on hand (dry milk instead of fresh, potters clay instead of Surround) in the forumula and it stays on the trees well. I like the color – more gray than white. It’s fairly inexpensive, too. I just slather it on with an old paint or chip brush, about a foot up on apples and pears, in the spring. Like Scott mentioned with the Neem, I make sure there’s plenty around the base. Since I used up my latest batch this spring I may try Neem next year though. I think it’ll be a bit easier.
Fedco has a good article on various strategies to defend against borers: Pests and Diseases Guide - Fedco Trees Last week I found the first tree in ten years with borer damage - significant borer damage - I killed three and when I got done carving out the damage it was left with maybe half of the bark. For some no good reason this tree, which is out of the main loop, never got painted, plus it had vegetation growing around it. This is why I bother to do the anti-borer paint. It’s worth it. Sue
I just got in from working on some of the trees. I weeded 5 apples and inspected the trunks for damage.
One tree had a couple holes, but they weren’t straight, so it was difficult getting the wire all the way in. So, I didn’t get anything out, but there may not have been anything in there. Most of the other damage appears to be just under the bark.
The bark on some of the rootstocks appear to have partially sloughed off, I don’t know why, other than sunscald damage, combined with freeze/heat cycles. This may have created opportunities for the insect damage.
Thanks Sue. I have nearly a full bag of Surround, so I can use that. What is in your ‘paint’, and how much of each ingredient?
Regarding the damage caused by the insects, I looked for the damaged bark and reamed out the bad wood with the wire. It left some ruts in the bark. Is that what you mean by carving out the damage?
I also have some neem oil concentrate. The instructions say for insect control use 1-2 ounces per one gallon of water. I went ahead and gave the tree trunks a drench of this solution today. I hope that was okay, but don’t know how long it will be effective. That’s why I need to paint the trunks.
Bob, I’d recommend using the Fedco receipe in the link above; that was what I based my solution on. For more info on apple borers and using Neem you might check out Michael Phillips articles on his website: https://www.groworganicapples.com/organic-orcharding-articles/
I used a combination sturdy wire in the tunnels and small sharp knife to carve the damaged bark away, striving to leave smooth edges along the good wood for healing. When done I put a wider hardware cloth cage around and filled it with fresh wood chips up over the damaged area. Something I tried a few years ago on a vole girdled plum and it worked. This was much worse but figured it was worth a try. I’ll let you know next year! There’s a post somewhere on the site where I described it and where I got the idea.
@scottsmith - given the wide variations in environments, methods and ingredients I guess I’m not surprised someone may have had a bad experience with Neem, or anything else. Since Michael Phillips has had success for some time now using Neem if I do go with that I’d follow his recommendations. Then again, I might just stick with my oil/milk/quick lime mix. It’s a bit messy but it’s worked.
Thanks again. I probably need to clean out the damage more thoroughly and try your wood chip and hardware cloth technique, if I can find some chips, I do have some hardware cloth. Do the chips have to be finely ground up, or coarse?
Regarding the slurry to put on the trunks I did read the article you posted, and it mentioned using Surround as an alternative. I guess the main point is get some kind of thickish white paint like material on the trunks for prevention. I think I might make try a paste of water, Surround, and maybe some milk and see what I get. I also have some Turbo sticker, so maybe a bit of that would help, too?
After @scottfsmith mentioned possible damage with neem on apples, I did a search on the site and I think the person he was referring to having an issue with it was @HollyGates, he lost a tree when he painted neem oil on it. I did a thorough search online about bad effects on apples with neem and really couldn’t find anything definitive.
I didn’t paint any oil on the trunks, it was a gallon of water with 1.5oz of neem oil concentrate, mixed up in a sprayer. So it’s about a 96-1 ratio of water to neem oil. Hopefully it’s so diluted it may not matter. Now I’m a bit paranoid that I may have hurt my trees, guess I’ll have to wait and see what happens.
No Worries! I am sure there is no problem with a regular neem spray. People spray that all over apple trees all the time at that concentration.
This topic reminded me I had not done my annual neem treatment on the peach trunks so I did it this morning. It is very important to do it every year, I learned my lesson the hard way on that one. I am noticing several of my older peach trees are in decline and I think it is related to all the borer damage they took over the years.
Wow Sue, that is an intimidating picture. Kudos to those of you doing surgery efforts to save a tree. Now my nightmares can feature borers instead of zombies.
