Why do so many websites say not to mix sulfur and dormant oil?

I’m pretty sure many people on this forum say it’s fine to do so.

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I’ve done it with no problems.


Lime-sulfur and dormant oil have been a traditional winter spray for decades.

I’ve damaged new leaf growth doing that. I think that is the only reason, although I’ve read not to spray it when it is hot as well.

from my lime sulfur label:

"When applied as a true dormant spray before growth begins, Lime Sulfur ULTRA can be used with oil to increase the penetration of the caustic sulfur into the surface of the infected tissue. Lime Sulfur ULTRA rates are reduced when green tissue is exposed.The potential for phytotoxicity of oil product and/or oil product mixes has not been fully evaluated for all crop varieties in all growing areas. Small plot tests are prudent to determine safety margins of particular varieties for specific environmental conditions in different growing areas.

USE RESTRICTIONS: Once green tissue appears, do not mix oil with Lime Sulfur ULTRA; oil will carry sulfur into green plant tissue causing injury…"


When i said dormant, I meant there are no leaves yet

These recipes from Cornell will likely never be on any forums either. This guy uses Sunflower oil as dormant spray.

Not many people talk about Bordeaux mixes either.

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