Dormant Oil and Evergreens

[Nickrosis]

What's the thought on timing of dormant oil sprays with evergreens? At this point, it's too late for decidous plants as things are leafing out in my area now. For evergreens, though, they've been leafed out all along... The label on Damoil says that the product should be used carefully/lesser concentrations on evergreens like spruces. Thoughts?

What about evergreens like euonymous?

 

[Stump Man]

I

What's the thought on timing of dormant oil sprays with evergreens? At this point, it's too late for decidous plants as things are leafing out in my area now. For evergreens, though, they've been leafed out all along... The label on Damoil says that the product should be used carefully/lesser concentrations on evergreens like spruces. Thoughts?

What about evergreens like euonymous?

I found that dormant oil will take blue color out of the Blue Spruces.

 

[alanarbor]

I use the petro canada 10E, so I don't worry about even decidous trees, except the blue bloom on blue spruce. It's the impurities in the oil that do the damage. Move to a higher quality product, and you'll be able to extend your oil spray window a lot longer.

and spray away on the euonymus!

 

[Hemlocklady]

I have wanted to try the petrocanada Purespray but can't find a retailer (even from PetroCanada), so I am hoping you might tell me where you get it. I'm in NE Georgia, but maybe they would ship.
Thanks
Sarah

 

[John Paul Sanborn]

I've found that with the loss of the waxy coating on the needles you increase the likelyhood of drought stress on most conifers. Soap is better, and if possible a contact product with a sticker.

 

[Nickrosis]

I find the whole idea rather silly. Dormant oil makes sense for certain deciduous species, but for the most part, it seems like a salesperson strategy to sell another stop!

 

[sgbotsford]

Wouldn't a lot depend on what you are trying to do? E.g. Spruce are subject to spider mite. Would dormant oil be effective in knocking down the population?

I can see the issues with it potentially dissolving the waxy coating. That's why it takes the blue out of blue spruce. Soap does the same thing. The blue is from tiny beads of resin on the needles. The more there are the whiter it is, the smaller they are the bluer it is.

But if the goal is smothering bugs, wouldn't the dessicant aids such as wilt-pruf work for that?