Using Lime Sulfur as Dormant Spray on Broadleaf Evergreens

[Apex37]

Anyone know if it is safe to use diluted lime sulfur as a dormancy spray on broadleaf evergreens?

I know they’re safe to use on conifers and deciduous trees after leaf fall, just wasn’t sure if it can be used for my boxwoods, hollies, and pyracanthas.

 

[Dav4]

Anyone know if it is safe to use diluted lime sulfur as a dormancy spray on broadleaf evergreens?

I know they’re safe to use on conifers and deciduous trees after leaf fall, just wasn’t sure if it can be used for my boxwoods, hollies, and pyracanthas.

My reservation would be the fact that broad leaf evergreens tend to be acid loving/alkaline intolerant plants and lime sulfur is very alkaline and might be detrimental if/when it gets into the soil.

 

[Matte91]

I use it on my pyracanthas without any problems.

 

[caffeinated]

Yes it's safe during dormancy as long as you're diluting it to prophylactic use levels. If you're lightly spraying it on your foliage, it shouldn't really be getting into your pots aside from some drips, so not really an issue. I do it every January on every tree outside. Only about 80 trees, mostly young, but hasn't adversely affected any as far as I could tell. Plenty of broadleaf evergreens in the mix.

 

[penumbra]

Using Lime Sulphur and dilution rate

All, Like all of us I am interested in keeping my pines pest and fungus free. Mr. Julian Adams stated that he uses lime sulphur as part of his regimen. We have lots of humidity here on the East Coast. How should Lime Sulphur be used as a dormant spray? What is the dilution rate? (Bonsai4me...

www.bonsainut.com

 

[BillsBayou]

Anyone know if it is safe to use diluted lime sulfur as a dormancy spray on broadleaf evergreens?

I know they’re safe to use on conifers and deciduous trees after leaf fall, just wasn’t sure if it can be used for my boxwoods, hollies, and pyracanthas.

My general rules for lime sulfur. Not all of this may apply to your application.

A) Why do you need to spray? What do you hope to achieve? Always connect these: Tree-Need-Product-Application (what species, what's going wrong, what to use, how and when to use it)

B) "Dormancy spray" is almost synonymous with "Dormancy oil". See web page "Dormant Sprays and Prepping for the Year" from the Utah State University. It is primarily an insecticide used to smother the little buggers.

C) Lime sulfur is not strictly a dormancy spray. It is an all-season spray. It is a fungicide/insecticide that has applications during most of the year. Only use it when temperatures are below 85°F / 30°C (303 Kelvin ). Lime sulfur can kill many species of insects by penetrating their shell or killing the eggs of the creatures.

D) Lime sulfur cannot be applied within a month (before and after) of using horticultural oils. Phytotoxins may be released and kill your tree. Something to keep in mind. Lime sulfur will dry to the tree and stay there for weeks.

E) Broadleaf evergreens do not have dormancy periods. Green means grow. Never use a dormancy spray (oil) on green leaves. You cannot predict the results and potential damage to your tree. But feel free to experiment and report your findings.

F) When you say "diluted lime sulfur", are you talking diluted lower than the recommended dilution? In my understanding, you should never apply undiluted lime sulfur to any living thing.

G) We primarily use lime sulfur straight out of the bottle for lightening and protecting deadwood. This is, however, not how the product is labeled for use. Product labels typically clearly state "It is a violation of Federal law to use this product in any manner inconsistent with its labeling." Some manufacturers state that their lime sulfur is not for use in residential applications. Backyard bonsai may not be the place to spray this (in a legal sense). If you must spray, do not use a fine mist and do not apply on a breezy day.

H) Some backyard scientists will make their own lime sulfur. However, it is rather dangerous due to its caustic nature. Your neighbors won't like the smell at all.

 

[Deep Sea Diver]

I know some old hands are inclined to scoff at this sort of advice, yet being a Chemical Hygiene Officer for years, I just have to state the following:

One should use extreme caution when handling and using Lime Sulfur. It is very hazardous to humans breathing, on skin contact and to the environment.

That said we use it often on our home and the museum trees… and use appropriate PPE.

This means working outside and using chemical splash googles, heavy nitrile gloves, appropriate cartridge respirators, long sleeves, long pants and shoes. (These are regular items serious hobbyists should have available anyways)

Also store the product in a secure ventilated area within a secondary container safely away from children, pets etc.…. and please don’t pour the excess down the drain.

Here’s the latest Safety Data Sheet I could find easily on Lime Sulfur 2020. Please read before using.

btw, even diluted the product poses a hazard.

cheers
DSD sends

 

[JoeR]

I know some old hands are inclined to scoff at this sort of advice, yet being a Chemical Hygiene Officer for years, I just have to state the following:

One should use extreme caution when handling and using Lime Sulfur. It is very hazardous to humans breathing, on skin contact and to the environment.

That said we use it often on our home and the museum trees… and use appropriate PPE.

This means working outside and using chemical splash googles, heavy nitrile gloves, appropriate cartridge respirators, long sleeves, long pants and shoes. (These are regular items serious hobbyists should have available anyways)

Also store the product in a secure ventilated area within a secondary container safely away from children, pets etc.…. and please don’t pour the excess down the drain.

Here’s the latest Safety Data Sheet I could find easily on Lime Sulfur 2020. Please read before using.

btw, even diluted the product poses a hazard.

cheers
DSD sends

Interesting that it is corrosive to copper and aluminum- I wonder what that means for spraying wired trees, if anything

I used LS on trees as a dormant spray last year and am not sure it's super effective, but am about to apply some this week. Daconil stunted growth. It feels like a futile battle with fungus here

 

[Darth Masiah]

I used LS on trees as a dormant spray last year and am not sure it's super effective, but am about to apply some this week. Daconil stunted growth. It feels like a futile battle with fungus here

i was trying out spraying powdered wettable sulfer at 2 grams per gallon with a pinch of yucca powder on my pines to prevent brown spot fungus. i sprayed it on just about all my trees this spring. didn't seem to bother the kotohime leaves at all. i want to see if it'll cut down on some black spot, too.

 

[WNC Bonsai]

In reponse to the OPs question you need to be careful using it on broadleaf evergreens. While most confier needles have a thick enough cuticle to survive the caustic effects of lime sulfur some broadleaf evergreens do not. I have never seen a listing of which ones do and do not, the only one I can remember is not to use it on azaleas. Fortunately none of my broadleaf evergreens are subject to many pathogens so I don’t use it on any of them.