When is too late for copper and dormant oil?

General Fruit Growing
1

Well, I blew it. Between procrastination and the unexpected early blooming of many of my trees, I didn’t get to put on my dormant oil and copper spray during dormancy on many of my trees. I suspect I am not alone in that, and others may have the same question I do: Is it too late? What should I do now?

So, almost none of my trees have actual leaves out yet. But many are blooming and some are in that state after petal fall but before leaves come out. Still others just have flower buds swelled up but not opened.

What should I do? Since I’ve heard copper can burn leaves and maybe blooms, can I still spray dormant oil without copper on the trees with no leaves? Or will it hurt the blooms or the closed buds? Or should I spray copper on those without open blooms and not oil? Or do something else?

Obviously I really have no idea what to do at this point. But it really hurts me to not get any copper or dormant oil or both on many of my trees. I had some diseases last year that I was really hoping copper would help with, and of course I always have tons of insects that I hoped oil would help with!

What is the very last stage of a tree at which a person can apply some copper? What is the last stage that a person can apply dormant oil? Of course this is my fault, but I’d really like to know I have any options left for trees that have swollen buds, open blooms, petal fall, or even tiny leaves. Are any of those stages still suitable for either or both sprays? Thanks (oh, if it matters I’m talking about almost all varieties of trees except apple…most of them are still quite sleepy.

2 Likes
2

This is a great guide http://www.goodfruit.com/working-with-copper/. It’s really to late this year at the stage your describing on some of your trees. I took a chance and sprayed some trees later than I should but before flowers were formed. Anything much past green tip is bordering to late for my pears. Copper is typically applied with oil and it can get very tricky. Here is another guide http://extension.oregonstate.edu/gardening/dormant-sprays-can-help-reduce-pests-disease-home-orchards. If you go off this guide http://extension.oregonstate.edu/gardening/node/753&ved=0ahUKEwj7k97Rz8bSAhUGBiwKHQWfCg8QFggsMAA&usg=AFQjCNGY8tu650L0Cxo0FwsRZssbA9o3AA you should get great results. I definitely put my oil on to late this year but oil causes splitting in the bark if applied below freezing temperatures. Here is another guide elaborating more on your question http://marinmg.ucanr.edu/Marin_Master_Gardener_Help_Desk/Leaflet/Treating_fruit_trees/. All trees are different so never apply the usual to fruit trees such as sweet cherries because if there is any green showing it’s to late for them which is not true for sour cherries http://msue.anr.msu.edu/news/dormant_sprays_for_disease_control. Unfortunately dormant sprays are meant to be applied to dormant trees primarily. You still have a great opportunity on fungicides and pesticides so the good news is you have not lost any fruit yet and should still wind up in great shape. If the buds are not flowers on some of the trees its not to late. I’m not sure I will get away with the stage I sprayed some of my pears at but I know copper buys me a few degrees of cold tolerance so I gambled Almond Production Manual - Warren C. Micke - Google Books.

2 Likes
3

I’m having to compromise the best timing for oil/copper spray due to having several different pears and apples on the same tree. This year I started spraying when the first pears were at loose cluster which also means the other later blooming pears and apples were sprayed. At this time I also sprayed the other apple trees that were so close they would have been partially sprayed. It has been about two weeks since I sprayed and a few of my crabapples are showing a little bit of green leaf so as soon as the rain stops the other apple trees will be sprayed. I know this doesn’t answer your question but I’m sure some others are in a similar situation as I am. You might have an arrangement of you trees that at least some can be sprayed without damage to the ones that are at an advanced stage. Good luck and I look forward to seeing how others handle your situation. Bill

4

The links do a good job of explaining the proper time to spray copper/oil. Thanks Bill

1 Like
5

I spray tomatoes with copper many times during the summer and it does not hurt them. I sprayed copper on cherries in summer to fight black spot and they were fine. The oil that I use is called all seasons oil. There are temperature restrictions for it, but it is supposed to be used in all seasons. I ran out of copper and our stores do not carry copper this early in the season (no tree growers at all?) so I’ll spray latter when I can find it.

1 Like
6

I don’t usually use oil on my trees but I’m thinking about spraying Damoil with Kocide? I’ll do research but does anyone know off hand if spraying those 2 together during dormancy is OK?

1 Like
7

Ask and ye shall receive really is the rule of thumb around here, and I very much appreciate it, so thanks all of you! @clarkinks links were especially helpful, so thanks for that! Also, for others who may see this thread and be in a similar situation, I also found a really good old thread right here on GF.org which was very helpful to me and likely would be for others who are running late this year:

BTW, the good news is the vast majority of my trees are still within the guidelines for both sprays, so if I get them done in the next couple days I’ll be able to have most of my trees treated, with the exception being apricots and most plums. I think I may stil spray the trunks and first bit of lower scaffolds that don’t have leaves or blooms. Maybe that will still give me a LITTLE protection.

Thanks again

1 Like