Lime Sulphuring Deciduous Trees

[MelaQuin]

Many enthusiasts recommend spraying a weak solution of lime sulphur on deciduous trees when they are bare to kill any bugs hiding in the bark. This is good but there is always a risk that the lime sulphur will get into the roots and kill the tree.

So do it upside down!!
When I am repotting my deciduous trees I bare root the first tree, hold the tree upside down over a spread of newspapers and thoroughly spray trunk and branches with lime sulphur [1 part LS to 15-20 parts water]. The tree slots between two horizontal planks with the nebari/rootball holding it up, wet newspapers go on the roots to keep them moist and I start root pruning the next tree and then lime sulphur it. By the time I have my third tree ready for the rack the first is dry and can be potted. And so it goes. There is no danger whatsoever of getting LS into the roots because the LS is draining away from the roots. You can be sure to get into every nook and cranny [particularly on corky barks] and under all branches in a way you can't when the tree is upright in a pot. The job also goes much faster.

Wherever you spray your tree be sure you don't get LS on any nearby foliage or it will die. When the LS dries it leaves white deposits so that's why I recommend a thick spread of newspapers where you spray and under the hanging/dripping bonsai.

Once the lime sulphur is dry the tree will be okay but I am still careful about watering for the next day just to be sure, just that bit of extra care to be sure no LS gets washed into the soil.

[PeterW]

Your kidding right? Ive been spraying LS on my trees for years, the only thing i watch for is that i dont get it on any azalias! 20:1 Mixture. I spray it on in late May, June, and July. I also spray it on again later if need be but i make sure that the conditions are right to do so. It does leave a white deposit on the leaves but hey thats all good with me provided it gives me good protection from pests etc. I wouldnt spray a tree that was to be shown within the following few weeks. Have you actually lost a tree because of LS or something?
Peter

[Bretts]

Thats intresting. I lime sulfured my trees one year but I was told to do this at the start of winter. I don't understand how this kills the bugs so I would not know if it makes a difference?
I was told the discolouration left by lime sulfur would be gone by spring. I was sure I could see it all through the growing season on the smooth bark of the hornbeam. I have not used it on live wood since.

[MelaQuin]

I have never sprayed it on leaves, using it only on bare wood. No, I have not lost a tree but enthusiasts far senior to me in experience have always cautioned seriously about keeping it out of the soil and I have taken that on board. Interesting to read your experiences. Thanks for the input.

[PeterW]

I have never sprayed it on leaves, using it only on bare wood. No, I have not lost a tree but enthusiasts far senior to me in experience have always cautioned seriously about keeping it out of the soil and I have taken that on board. Interesting to read your experiences. Thanks for the input.

I wonder why, can you ask them for an explaination as to why it shouldnt come in contact with the soil? I hope i am not doing harm by using it like that. I spray all my benches and pots and everything with it when i spray also. I mix up 50 litres and just spray everything with a 12 volt pump and spray unit conected to my mower.
Peter

[MelaQuin]

I have always been warned that it will kill the roots and the one tree that got lime sulphur in the soil was washed, rewashed and all but put through the washing machine [a bit of an exaggeration] to ensure that any trace was removed. I have taken that message on board that if I lime sulphur -full strength] deadwood I actually put the tree under cover for at least a day if rain is threatening. Yes, the word is that once it dries there will be no problem.. but I just prefer not to chance it. And yes, the tree survived quite happily after its well rinsed roots.

[PeterW]

I have always been warned that it will kill the roots and the one tree that got lime sulphur in the soil was washed, rewashed and all but put through the washing machine [a bit of an exaggeration] to ensure that any trace was removed. I have taken that message on board that if I lime sulphur -full strength] deadwood I actually put the tree under cover for at least a day if rain is threatening. Yes, the word is that once it dries there will be no problem.. but I just prefer not to chance it. And yes, the tree survived quite happily after its well rinsed roots.

Have you a tree that you just dont care for much? Use it as a crash test dummy, mix LS at 20:1 and give it to it. rench the soil, spray under the leaves and on top of the leaves, all over the trunk....simply drench the whole tree. Dont wait for winter like you should, wait for a cooler afternoon and do it. The following morning, water as normal but give the folaige a good wetting also. Go on.....live life on the edge! Let us know how it goes.
Peter.
Ps...If you dont want to do it you will have to trust me and i will do it and post the result. Remember dont spray an azalia, and also i cant be sure how natives will handle it as i have never really had any!