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Borer repellent

Posted by Isa Campbell 
Borer repellent
June 28, 2018 10:10PM
Planning to do a 1% Neem trunk spray followed by kaolin clay/water slurry painted on. Does anyone have comments, suggestions or variation on this idea?

As a follow-up, what are your methods of dealing with the RHAB?

Vineyard Hills Community Orchard
Grow Ohio Valley
Zone 6a in Wheeling, WV

Edited 2 time(s). Last edit at 06/28/2018 10:45PM by Isa Campbell.
Re: Borer repellent
June 28, 2018 10:27PM
Also, wondering where the white interior latex paint fits in here.. or is that only for winter sun-scald?
Re: Borer repellent
June 28, 2018 10:37PM
I have used 2% neem for peach tree borers, and then filled cracks with a mixture of clay, plaster and diatomaceous earth. It doesn't seem to last very long however. The latex paint treatment for sunscald protection on the other hand lasts a good year or more. Maybe there is a combination of clay and paint for the tree borers that would hold up against the rain better.

Turkey Creek Orchard
Solon, Iowa (zone 5A)
Re: Borer repellent
June 28, 2018 11:18PM
You could just a straight up biodynamic tree paste mixed with neem and other stuff, like surroound. You'd get the BD500 action + silica sand action going from the BD tree paste + anything else you throw in there.

Mike Biltonen, Know Your Roots
Zone 5b in New York
Re: Borer repellent
June 28, 2018 11:23PM
I've seen where you can make your mixture - whatever it is - and use gauze as a kind of orchard poultice - you need to wrap it. Or just pack the wound as suggested and wrap with gauze. it will last longer. paint is just for sunscald, it will provide some protection against borers etc. However, my favorite fall approach is this - BD508 tree wash, followed by biodynamic tree paste PLUS (your choice) in the fall. Then in late May or early June, apply a dilute trunk spray of thymegard, entrust, pyganic to the trunk and lower scaffolds to ward off any borers - esp if you have problems. the two really complement each other and do as good as job as you can without really toxic shit. If you do get RHAB, FHAB, DWB - then dig it out, cut the wound back to green tissue and slather on pure neem over the wounded area.

Mike Biltonen, Know Your Roots
Zone 5b in New York
Re: Borer repellent
July 30, 2019 06:40AM
I just started using a bennonite clay with milk protein. It seems to stick REALLY well. When it's rinsed out of the tanks in large quantities, it seems to make the ground in penetrable to water and causes constant puddles. Not sure if there is any other drawbacks but I'll report back on how long it lasts.

I've also heard that you can add a little latex paint to bio dynamic paste (although not ideal organic wise) but will bind it well.

Zone 8:
Vancouver Island, BC
Re: Borer repellent
June 16, 2020 06:04PM
Hi all,

Good to see some discussion about borers and what to use for repellants. I was talking with another grower other day about borers and neem oil rates. He found that a 100% neem paint did some severe damage to his M111 trees, but other rootstocks tolerated it just fine. The above ground root-clump areas really suffered. Not all, but some died right around where there was a clump on the painted trunks. We were talking about what rates to spray/ paint and he is trialing different rates of neem mixed with canola oil, and we talked about the 2% neem drench spray that Michael recommends, and that made me wonder why the rate is 2%. Is 5% more effective? 10%? What can a tree handle (if it's just sprayed on the bark), what's too strong? And Michael, how did you arrive at 2%?!

In our orchards in Unity we have for three years now painted a mixture of neem surround and milk paint (roughly a third of each) on the trunks and that seems to help some... but last week i found one tree (that had been painted only last year) that had maybe 8 little tiny borers just barely under the surface of the bark, the frass quite bright against the white painted trunk, the borers easy to remove. Makes me wonder if my mixture could be improved, if it should be applied more liberally, more frequently, or if our borers are just starting not to care about neem and clay.

Looking forward to hearing more about what others are doing.

Zone 5a
Maine Heritage Orchard @MOFGA
Unity, ME
Re: Borer repellent
June 16, 2020 06:28PM
Very timely message, Laura. I've been getting a bunch of questions about this as it seems there is much damage this from borers, rodents, deer, sheep, weed whackers, etc. In the case of damage, I will just apply (well mixed) pure neem straight on a cleaned up wound and wrap it with a medical grade gauze (i.e., neem poultice). I have never mixed straight neem with anything else (except water) as I have seen too much phytotoxicity over the years. However, I will use the above for damage repair, let it settle for a couple of weeks, remove gauze, then mix with milk paint (or cut latex) with surround, Thymegard, and/or Entrust to prevent and control further borer damage. I've also heard of using parasitic nematodes as well (the blend is a bit more complex, so let me know if this is of interest) in a poultice blend that can then work their way into the damaged/infested tissue and "take care of" any new or missed larva. For other damage (e.g., voles, deer, etc.), I just stick with the straight neem poultice. I am not surprised to hear that some rootstocks/varieties may have differing levels of resilience, but don't have any specific info on that.

Mike Biltonen, Know Your Roots
Zone 5b in New York
Re: Borer repellent
June 17, 2020 04:25PM
hello, newbie here...
super interested to hear folk's responses to Laura's questions about neem application rates (how one come's to the different percentages) and if anyone else has experience with m111 being more sensitive. was just about to apply a high concentration of neem (mixed with other things) to trunks today actually, until i saw her post. in talking with another fella who applies straight neem to trunks (and who has many m111), they haven't noticed sensitivities, but he said he was gonna monitor more closely. he is intending to apply today.
Re: Borer repellent
June 17, 2020 06:03PM
Suggested neem oil rates for spray application range between 0.5% and 2.0%. We generally assume a foliar rate of no more than 0.5% biological fats (neem, karanja, etc.) to be safe as regards phytotoxic damage to leaves . . . but as observed in other posts in this forum, certain cultivars (oh, those tender pears!) seem especially sensitive and thus a 0.25% spray rate might be a better rate. Ditto when spraying perhaps any plant when temps are in the 80s and the sun is shining brightly. Applied to non-foliage (the trunk zone) is where the borer game begins. Translate that 1% or 2% concentration into costly gallon jugs of neem oil. Adding one full gallon into a hundred-gallon spray tank costs like $75 to make a 1% concentration borer trunk spray. Some spray splashes off-target but on the other hand we actually up the net concentration by saturating the soil zone right at the base of the trunk to make this strategy effective. Mesh trunk guards (for voles) help to contain the spray where you want it to go. It helps to sit on the sprayer when there's many trunks to treat, plus bigger trees are easier to protect since RHAB particularly goes for younger bark given the choice.

Part of my current strategy is to brush pure neem oil on younger trunks by the third week of June but only do a 4 to 8 inch wide band right at the soil line and not much further up. I like to pull soil back to expose as much as an inch of buried trunk zone, then apply, even puddling up ever so slightly, before pushing back the soil (or peastone or bark mulch). This 100% concentration is cost-effective directly applied but takes the labor of going from tree to tree thus why I'm only going to do this in the tender years. That could mean as many as ten years, especially where an apple orchard borders the woods where borer continues to thrive in alternate hosts and/or you are personally involved in some sort of karmic debt from a past life. Ha! I have applied pure neem to trees on Antonovka, MM.111, Bud.118, and Geneva rootstocks. The marvel of this is that it need only be done once a year whereas I have done borer trunk sprays as many as three times a summer. I still intend one trunk spray in mid July to larger trees but now see brushing neem on younger trees as replacing the need for a late June trunk spay. We are timing this to repel the female during the egg-laying period which runs from late June through August in northern zones. I will also note that I have only done the preemptive brush-on approach two years running at this point but that my initial use of pure neem to treat borer wound cavities goes back several seasons (along with a comfrey leaf wrap around the damage zone). The point being what does a trunk look like after ten years of such treatment? None of us know so keep that in mind.

Now let's bring in the nursery nuance. This is where Seth's observation of damage to adventitious roots (arising from burr knot zones) on MM.111 becomes relevant. Nursery stock may be planted deeper in the orchard so losing these potential roots that are above ground in the nursery would not be good. So sure, cut the neem oil concentration with canola or even water. Just be aware that renewing a lesser application rate like 10-20% may turn out to be necessary later in summer. Once a tree is planted in its orchard location, the soil line has determined which adventitious roots have legitimate rooting potential and so I wouldn't worry about hardening off burr knot zones above. But I also have not seen what Seth has seen so feedback on this should continue.

And just to be clear, we are giving all this focus to one damn beetle species RHAB because it kills young trees. Those of you dealing with Prunus borers are dealing with the progeny of moths, and that's where nematodes and spinosad have relevance in shifting an active infestation.

Lost Nation Orchard
Zone 4b in New Hampshire

Edited 3 time(s). Last edit at 07/09/2020 08:39PM by Michael Phillips.
Re: Borer repellent
June 19, 2020 05:14PM
super grateful for your thorough answer Michael. as a youngish person, i am amazed of folks who answer such questions with such detail and farm at the same time. hoping to find such balance in my later years smiling smiley

do folks recommend or have any used straight neem on the lower trunks of pear trees? i reckon the potential circumstantial sensitivity pears can exhibit in the leaf zone doesn't translate to the trunk zone, but wanted to make sure. we haven't seen any RHAB damage on our pear trees here, but internet search says RHAB can target pears too, though less likely.
Re: Borer repellent
June 29, 2020 08:49PM
thanks for the details Mike & Michael.

I am definitely interested in the possibility of adding parasitic nematodes to the poultice if it might help with round headed app borer (is it only effective in killing purnus borers?). I seem to always miss some and will often times not notice until the next year. terrible! I should also emphasize that i really like to use the milk paint powder in conjunction with the surround for the neem poultice, and have wrapped with comfrey on occasion, but have not tried gauze. and that reminds me- a few years ago Eliza recommended using fine crushed vermiculite for the glitter effect, as you might use bird scare tape or those big eye beach balls hanging in fields. does organic glitter confuse pests? maybe i'll experiment.

anyways, thanks for the information about spraying neem on young trees & the rate reasoning. i usually skip spraying the pears if i'm using neem, and i also tend to skip the neem and karanja all together when I'm not feeling patient for slow hot water to fill the 100 gal tank, and then i just go for teas kelp fish and cold cold h2o, maybe with spinosad or bt. And yeah, neem really is some expensive oil to be drenching our trees with, 100 gallons doesn't cover all of our trees anymore! (and how did you know about my karmic debt from a past life?? same same?) does the phytotoxicity build up just happen in a season in the leaves, or is that more of a life long systemic concern? if we paint trunks with straight neem year after year, might we be doing more harm than we think?

and the nursery nuance...adventitious roots- burr knots- right! thank you for the terminology refresher. i'm glad to not be dealing with more than 100 nursery trees, but i'm also so curious about the work and Seth's experimentation. i wonder if Seth has seen this discussion, maybe ill give him a call today. might need to loop Jacob in as well. he grows nursery trees on the same assortment of rootstocks, and many other woody species, too. is thymeguard as good as i hope? i'm ordering some to add to our poultice for this year. looking forward to seeing how the different mixes do for our trees.

Laura, Maine Heritage Orchard
Zone 5a in Unity, ME
Re: Borer repellent
June 30, 2020 03:43AM
A slightly oblique observation today: A neighbour had dramatic success last year in controlling lily beetles by spraying neem oil. When her tomatoes were attacked by flea beetles this year, she went at them with neem. She asked me to look at them today, (2 days later) - they are blackened and shrivelled. I asked her what concentration of neem she had used. She responded, "I don't know... I just put a bit of neem in the sprayer, added some dish soap and water, and sprayed." Moral: concentrated neem is phytotoxic to green tissue.

And just to complete this tale, I made up a measured 0.5% concentration of neem and sprayed it, (mainly on the brassicas, but also on the tomatoes). It shows no sign of harming any of the vegetable plants. But nor does it seem to, in any way, affect the flea beetles either.

Broomholm Orchard
Zone 5b in Nova Scotia
Re: Borer repellent
July 10, 2020 10:12PM
We completed "neeming" the east block trees finally. It was interesting to find a few borers a foot or two off the ground where the female must have decided last year to avoid the oil-treated base of the tree. This method really works! And what's so appropriate is that this is tree medicine for trees, a powerful gift indeed. I'm still not inclined to paint neem higher on the trunk, up to first branches. One, that more than trebles the amount of neem oil (cost) required. Two, the female will still lay some eggs "above" regardless. And three, these misplaced grubs are much easier to find as they make a nearly vertical cavity in trying to get to the soil line. Such narrow damage will readily callus over.

Let me address one thing Laura asked above:
Does the phytotoxicity build up just happen in a season in the leaves, or is that more of a life long systemic concern?

Biological fats on the leaf should be thought of as a magnifying glass on a hot sunny day. The foliage can get "burned" beneath a spray app with a high enough concentration of oil rather than the cause being some accumulation of fatty acid constituents in the leaf..This is a short-term, physical manifestation only . . . though I can see how the term "phytotoxic" might imply a tie-in to phytochemistry. Neem's contributions in that respect are all to the good. As far as year after year applications directly to the base of the trunk, my sense is fats are good for bark tissues but truly only time will tell.

Lost Nation Orchard
Zone 4b in New Hampshire

Edited 1 time(s). Last edit at 07/10/2020 11:00PM by Michael Phillips.
Re: Borer repellent
August 05, 2020 05:25AM
I came across this paper on borer controls from 1944 out of Oregon State College. Out of curiosity, I was wondering if anyone has ever tried any of these “old timer” wash recipes?

https://ir.library.oregonstate.edu/downloads/br86b4800]1944 Oregon State College - Borer Control[/url]

Slaking lime and crushing moth balls, sounds like fun!

Philippe Smith
Bristol, Quebec
Zone 4B
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