Dormant Spraying Fruit Trees
Winter and spring are the times of year that we apply dormant spray to our fruit trees and other deciduous trees. There is still time to spray in our area,zone 14-15 in Napa. The reason you should spray is to kill wintering over insects and fungi. A combination spray of summer/winter dormant oil and copper sulfate should be used. I also recommend that a spreader sticker be add to the mix, this will improve the ability of the spray to stick to the branches when it rains. Now,I need to get on my soap box for a minute. Always read and follow all the direction on the chemical your using. Remember, more is not better when mixing any chemical. Do not wear leather gloves,they will absorb the chemical and ever time you put your hand back in the glove you expose yourself to that chemical. Wear long sleeve shirt and eye protection, not your glasses but real goggles, remember you going to be spraying over your head and the material will be dripping off the tree.Do not use the same sprayer you used for Round-Up. I know you rinsed it out real good, but take my advice on this one, have 2 sprayers one for Pesticides and one for Herbicides. Last but not least, mix only what your going to use and don't ever leave chemicals in your sprayer, (it eats the seals on the sprayer) you might forget what's in it and hurt a plant you really love. Ok I am done.
One thing you should know if you have Peach Leaf Curl. You will spray and still have it this spring . Peach Leaf Curl is a fungus and is very hard to control. It may take a few years to totally get rid of it.When you spray the dormant spray ,don't forget to spray the ground around the tree.The fungus will winter over in the soil.The copper is a fungicide. If your tree is small you can pick the effected leaves off. Peach Leaf Curl does not effect the taste of the fruit it might effect the amount of fruit the tree produces,but I am researching this
You should try to spray 3 to 4 time from winter until early spring.The last spray should occur before bud break or what's called the "Popcorn stage". This is when the bud just start to break and you can see a little white showing from the bud tip. If you were to spray after bud break you could burn the fruit buds off, if you not sure, E-mail me and I will get back to you,or talk to your County Agricultural Adviser,or your local Masternuserymen. There's no such thing as a dumb question.