Here, the common practise is to spray almost everything with copper sulphate / bordeaux mixture as a preventitive measure in the winter months. I guess it also prevents early awakening of the tree if the weather goes hot (correct me if I am wrong please). Last winter, my gardener sprayed everything with bordeaux mixture, including the japanese maples twice with one month interval. This year, before letting him do it, I would like to know first whether this is a correct thing to do and whether it can be harmful in anyway for my trees, especially the japanese maples. What do you think about this? Should I go ahead and spray them? If so, when and how many times? Do you advise anything else instead of bordeaux mixture / copper sulphate to use in winter as a preventitive measure, or anything to be used in addition to it? Since my climate is at the edge for japanese maples, I would like to make sure I do everything correctly. (I am in Izmir Turkey, next to the mediterranean sea. USDA zone 9b) Thanks in advance.
Unless you are in an area that is known to have Spring issues with blight or blast forms of Pseudomonas and perhaps Anthracnose, then applying a topical fungicide or bacterial spray is not recommended for the palmatum type plants. I've never used a fungicide spray on the palmatum type Maples and much of the time advise others not to use the spray where they are growing these Maples. Yes, there are some areas that may want to use a preventative spray for Spring forms of Powdery Mildew, Downy Mildew and water mold fungi in cooler, wetter and humid Spring climates but that generally is a case by case situation, depending on how frequent, how often, these issues arise and is not the norm, not an issue at all around here, for warmer, less humid and drier Spring climates. [Should someone be in an area whereby there are prevalent or intermittent issues with Deep Bark Canker or Shallow Bark Canker of Silver and Sugar Maple, then it may be advisable to use a Copper sulfate spray as a preventative.] Be very careful mixing Copper sulfate with a light or horticultural oil as the oil can cause wood burn for many Maples. Mixing Copper sulfate in water is the preferred method of choice. Should you want to use this fungicide as a preventative spray for the leaf spot, both fungal and bacterial, diseases in the Spring in areas that are known to be susceptible. Jim
Here in MA, USA, we have a terrible problem with winter moths. The suggested treatment is a dormant oil spray before they hatch.The timing of the late winter/early spring treatment is area dependant. After/during leaf out I spray with a Spinosad based product once a week untril they stop eating (usually the beginning of June here in zone 6).
mr shep, thank you for your post. The problem is, there isn't any knowledge about issues in spring for maples here. I have in total 15 japanese maples, 1 small sugar maple and 1 small red maple, I probably have 95% of all japanese maples in home gardens in this area... (The population of my city is 3.5 million btw) I guess that in future, the number of japanese maples in gardens will increase once people realize that it is doable but until then there is no data nor knowledge about the problems they face in spring. The winter and early spring is wet here, with plenty of rain. For fruit trees, copper sprays are recommended here and mostly the trees are sprayed with bordeaux mixture once when the leaves drop and once before bud break (I think). Last year I let my gardener spray all my trees with bordeaux mixture including the japanese maples because of this... As per your recommendation about not using sprays, I will not spray my japanese maples this year (also having read about its dangers, I will not spray my fruit trees either and see what will happen). Is there anything else I can use that does not harm the trees and/or environment? For example I like to use a product made only of ws sulphur on my roses (I hate chemicals) for powdery mildew and I haven't had much problems with powdery mildew eventhough many of my neighbors did. Can I safely use this on maples as well (monthly maybe?) after spring when they have leaves? ws sulphur applied on leaves should be safe right? Anything else do you suggest as preventitive measure both in winter to be applied to the bark and in spring to be applied to the leaves?
there isn't any knowledge about issues in spring for maples here. There is little cultural information on palmatum type Maples most anywhere - offline or online. I've already posted more general information on some diseases in this forum than you will find in any book. Some people feel that Powdery Mildew is an issue for them when in reality the real culprit may be Downy Mildew in some areas. Most people do not equate Anthracnose as being an issue but it can be with some of the palmatum type Maples, I've seen it in Oregon and even in some locations in the San Francisco Bay area - East Bay, West Bay, South Bay and Marin. Tar spot can be a real nuisance along the Northern Coast of California on Maples both palmatum types and native Big Leaf Maples. Just to name a few instances. [I will not spray my fruit trees either and see what will happen This may be a huge mistake. Fruit and nut trees are in my expertise area for many years. If you are in a location in which foliar diseases are an issue such as Peach Leaf Curl or worse yet Brown rot or Hull rot then it may be imperative to spray your trees. I manage Fruit, Pome and Nut trees in a commercial operation. There is no way that we would not spray our trees every Spring with a light oil and either Copper sulfate or a Copper hydroxide spray as a dormant spray and/or a pre-popcorn to early bloom spray. Sometime go to this web site and read the recommendations for various plants. Keep in mind, that although I am partial in my viewpoint, the content therein is considered by many as the world standard. The whole premise is that we do not spray a pesticide unless it is absolutely necessary. In commercial operations there is a specific need to use fungicides for certain crops. Even certified organic growers are able to use some of these same sprays if need be. Where I draw the line is in the use of herbicides, soil fumigants and insecticides and am very selective about using them, much more so than most people.] Home Page - UC Statewide IPM Program: As far as using a dormant oil for specific overwintering insects then the use is applicable where needed. The use of oil sprays for most people with Maples generally is not needed. All I did was point out a caution and to further that caution it is my recommendation to only use an oil spray while the Maple is dormant - Winter to pre bud swell in the Spring. Jim
