Dormant Spray and Copper Spray


I’m going to miss this great spraying weather waiting for my Nufilm!


Dormant oil works by smothering. If it’s on for the day it will work so you don’t need a sticker for that. If you are also using copper than yes a sticker will help. By late winter it will all be gone so I skip the fall spray and just do it in the late winter.


We had similar temperature here yesterday as well and did the dormant oil spray too.


I missed my window to spray Kocide on peaches yesterday…a bit breezy but perfect temps around 50. Sigh


Spring before tip green for leaf curl
After green tip, close to early pink for fire blight


I like to do it twice - once in late fall, once in spring, but the weather hasn’t cooperated so far.

And now I’ve shut off the outdoor water for the season.


I think twice is a waste of time in most cases anyway. Maybe the weather did you a favor. If you succeed with just a single spray it will probably spare you from the fall chore for the rest of your life.


I wanted to spray oil on the magnolias, too, for scale. But they still had all their dead leaves hanging on.


Yeah, scale is a different animal. I hate the bastards. They are becoming more and more a problem in my orchards when a single oil app in spring used to keep them under control.


Has horticultural oil gotten lighter?


Apparently the magnolia scale needs to be treated in the fall and I waited too long because I was waiting for the leaves to drop.


I’m pretty sure the crawlers become active and vulnerable again in the spring. Have you looked up their life cycle. I haven’t because I’ve never been called on to treat them. My toughest scale is peach scale. If I treat it a couple of times I seem to get control with spring apps, but I also use a scale killing chem.

I’ve controlled San Jose scale summer flare-ups with that. What sucks is how it keeps getting more complicated. Global warming or weaker pesticides? Or having to use pesticides that kill more predators?.

Hasn’t become a big problem at the majority of sites I manage, but the more trees the more likely it is to become a problem.

And then there is the explosion of Marsoninna leaf blotch, which is showing up at a majority of orchards.

Spraying is my least favorite activity but I keep having more pests to spray.


I’ve only dealt with scale on potted citrus. Granted, I never tried anything too strong chemical wise, but the one thing that finally got rid of them for me was putting the plants outside for the summer. My only thought is that something(??) preyed upon them enough to get rid of the population. Don’t know though. If only it were always that easy…


Hardening off outside certainly makes plants less susceptible to sucking insects, especially aphids. I bring healthy parsley plants indoors and within a couple weeks they can begin to droop from aphid infestation.


That’s a fair point. It reminds me of Eliot Coleman’s contention that if you can provide for a plants cultural needs perfectly, there will be no pest issues. I don’t buy that hook, line, and sinker, but I think it’s fair to say that if you do everything you can to make the plant healthy to begin with, there will (likely) be fewer problems. Does that jive with your experience for fruit trees? I’ve only been able to apply that to vegetables thus far.


It applies to leaves to a certain extent but Eliot, although a master of organic vegetable production, is probably not very experienced with tree fruit.

We are growing species that didn’t evolve here so healthier fruit may actually be more attractive to insects and other pests. So far, breeders aren’t tending to breed for insect resistance, unfortunately. We are also bringing pests to the continent that natives don’t have resistance to.

As to your question, yes, a fruit tree seems far more resistant to death by pests if it is growing with adequate vigor.


Yeah, I figure all bets are off once you get to the actual fruit, since they’re meant to be eaten. Thanks for the good info.


I think they do, in early spring. My arborist seems to be familiar with them.


It’s a nice 52 degree day, no wind perfect for spraying copper. Next few days look good too. My plums and apricots are showing signs of bud break. Need to spray copper at some point to control bacterial spot on peach and fire blight on pear. But I spray all my trees for good measure. I’m wondering if I should do it today or if it’s too early to do it. I’ve heard that it should be done before trees leaf out but as late as possible. Thoughts?