Oil Sprays

Although I have several years of growing fruit now I still feel like I don’t know enough about dormant oil sprays. Going back about 20-30 years ago I used the combination of dormant oil/copper. After I sprayed the tree looked oily for a few days and after a few rains the tree limbs/trunk looked clean. I think but don’t know that these oils were thicker than the ones that I use now (all season types). My opinion is that the older version was better if used while the tree was completely dormant. I’m posting this with the intention of getting your opinions about the different oil sprays. I would like to know your thoughts about the different oil sprays and which ones you prefer. All comments are welcome.


Other post

Dormant Oil Question

Advice on dormant oil +/- lime sulfer

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Bill, I agree the newer all-purpose oils do not do as well as dormant oils. Looking at the first thread there it looks like seven (!) years ago I said pretty much the same thing:

My feeling about dormant oil is the higher viscosity the better, as the oil will smother better and longer if its thicker. So I usually use soybean oil which tends to be a bit thicker. Golden pest spray oil and Stollers nat’ral oil are two brands I have used.

I am still using those same brands as I only use them for dormant spray and they come in 5-gallon containers.

If I am spraying copper I also include a large amount of nufilm along with the oil. This combo will stick a very long time. But you need to be careful with clogging the sprayer, I have clogged it a couple times with this combo… something like 1tsp/gallon is about as much Nufilm as you want to use to avoid clogging.


Thanks Scott

Canola oil, baking soda and water.


Kris those ingredients are easy to get. Please share your ratios per gallon if possible. How effective are your results with this combination? Thanks



A dormant oil formula developed by scientists at Cornell University controls overwintering pests and foliar diseases. It contains 2 tablespoons of ultrafine canola oil and 1 tablespoon of baking soda mixed with a gallon of water.



Since oil and water don’t mix too well,I wonder how they get them to emulsify.My dormant oil recipe includes a little dish soap,like there is in two of their other recipes.


I’ve been using Dr. Bronner’s Sal Suds Biodegradable Cleaner as an emulsifier for neem and karanja oils. Works great!


This is an extremely timely subject for me though I have a slightly different question about spraying oil.
I’ve always used oil and copper in my late winter dormant spray, basically because so many different sources recommend it. HOWEVER, I honestly have no idea on earth of any particular insects or eggs or other pests that I am actually going after in my part of the world.

So my question is a simple one: Do I even need to use oil at all? One year I missed it and could tell no difference at all in anything. So what do you guys think? Is Dormant oil serving any purpose at all in my little orchard here on the TN/KY line? If so, which pests am I targeting and in what form? I really am considering only using copper this year. What say you all? @olpea , @scottfsmith, anyone?



I don’t bother with a dormant oil spray on peaches. I’ve never seen mites or green peach aphids up here, so it would be totally worthless for us.

We do spray a dormant oil on pears though. One dormant spray seems to control pear leaf blister mite.

Occasionally we’ll use some oil, at a more diluted rate, on apples during the growing season. Seems to help with mites, which are problem because some of the sprays we use.

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I use a heavy dormant oil late in fall and again in spring, if I don’t drop the ball, with the idea that heavy oil applications help moderate codling moth by smothering emerging eggs. CM is really about the only thing I have to worry about on my apple. But I don’t know how well it helps because I also spray with spinosad, and usually will use spectracide in the first two sprays as well. (So far I’ve been doing pretty much OK with this approach. This year I’m going to use malation in the first two sprays and I expect to do that next year, and maybe the next, as well.)

I’d like to know just how much the oil helps with things like codling moth, but I’m not willing to quit using the spinosad and other insecticides to find out!


Here in our wet winter northwest environment I use Wet and Forget once on the older tree bark that tends to get burdened by layers of moss and lichens. I do this early right after leaf fall and trees are dormant on a warm sunny day. Then for several weeks I use a stiff brush to brush off the dead materials rather than waiting for wind and rain to wash it off. Then I apply a liquid copper application once I have the bark clean. Following that each moth I use a mixture of lime sulphur to treat the entire tree and all buds until dripping wet. My sprays all use Turbo sticker. Years ago I used oil sprays but could not really see much benefit.
Kent, wa


Wet and Forget!?! The stuff that is used to remove mold from houses and decks? That is funny. I have a gallon of that. It has been sitting in my garage for several years . . . 'cause I keep forgetting that I have it!

I am so glad that you asked this question. I am going to use a dormant spray this year. I thought I’d wait till right after I prune. No point in spraying a lot of ‘clutter’. Should I spray before I graft - or after?

All our stores carry canola oil. Is there a difference between canola oil vs ultrafine and is the one sold to cook with okay to use?

Last year I used canola oil, a bit of dish soap, and water to spray my trees. I put it on THICK and they did fine. That oil expired years ago so it’s a perfect solution to still make it useful.

My opinion is that you should not spray oil and immediately graft because the oil might get on the cuts made to graft. I would think that as long as the oil was gone it would be okay. I’m facing the same issue with timing.

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Hi Mark,

Oil is mostly ineffective against major pests like codling moth, OFM, and PC.

The two moths overwinter in cocoons, underneath loose bark, loose boards/debris, wood piles, etc. It’s very difficult to get the oil on the cocoons because they are hidden/protected.

I’ve read that some people have had some mild success making traps for the cocoons/larva of codling moth. That is, tying various pieces of wood/plywood against the trunk of trees, then coming in winter/early spring and cleaning off/destroying the cocoons laid behind the boards.

This would only have effect on codling moth. OFM has a much shorter reproductive cycle, which would largely render the practice completely ineffective. PC pupates in the soil so the traps would have no effect on them either.


No clue… i think the ultra purists may even use sesame oil.

If you want to be more earth friendly maybe use Castile Soap instead of dishwashing soap. Its made from Olive Oil.

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