Can't claim to know much about trees. I've a large 30 ft tall by 30 ft round red japanese-type (?) maple tree on the front of my property in North Vancouver. It consists of 6 large trunks radiating our from the base (one is about 12 inches in diameter). It was healthy last fall, but with the leave coming out I noticed one of the truncks looks dead and another partially dead. Used a knife to scrap off the bark from the dead parts and noticed that light to dark brown streaks stain the underlying wood. The wood in the healthy parts doesn't appear to be streaked. Been here 4 years and remember that two or three similar trees further down the street died over the winter a couple of seasons ago. What could be happenning and can it be addressed? Noticed some mention on other websites to verticillium wilt (which can be treated?) and sugar maple fungus (which is fatal?). Figure next step is an arborists. Thanks (either to relieve worries or come to terms with inevitable!), Bruce
Hi Bruce: Japanese Maples are subject to dieback which is fairly common. In many cases dieback is a result of our neglect of our plants. There is no real need to go into detail about one form of Phytophthora we here in the warmer climates get hit by all to frequently that also causes dieback, even on healthy trees. If your tree was dying due to Verticillium Wilt it would be dead already. I am not all that familiar with Sugar Maple fungus (Ceratocystis coerulescens) as we never see it here on Japanese Maples unlike Peaches and Nectarines that can get hit with another form of Ceratocystis (canker). One form of Phytophtohora for us is lethal, however, not so much due to the injury the pathogen causes but when the Japanese Maples are attacked for us as the pathogen hits in late summer, early fall, causing a severe burn like Fireblight and affects the formation of new vegetative leaf buds that will over winter for us. If no new leaf buds form the tree will not leaf out in the Spring. The tree dies because there isn't any leaf buds that formed but the root system is still alive (mainly affects the small leafed dwarf varieties such as Beni hime, the true form of Goshiki kotohime, Hanami nishiki, the Oregon form of Okukuji nishiki, the true form of Otome zakura and Beni yatsubusa and Beni yatsubusa variegated. It is lethal on those forms in particular but can kill other forms also). If you can show me a pic of your Maple and then show me a pic of your dieback that will help but it seems like it might be a so-called "natural" condition that comes about from a few years of neglect. Yes, it can still be Verticillium involved that caused the dieback (there is more than one form of Verticillium also) but as long as you cut out the dead parts and baby your tree for a while you should be okay. Verticillium can kill just some major braches and leave others alone but if there is a wilting of the leaves allover first then you will see the lethal and irreversible form of Verticillium at work and there is nothing you can do or could have done to prevent it. I have a Matsukaze that always loses a large sized branch seemingly every year since I've had it due to Verticillium but the tree produces enough new growth that I, at least, have enough tree left for when the next branch dies next year. If the tree was going to die outright due to Verticillium it would have done so 14 years ago. Jim
In the Vancouver area, verticillium wilt is not always fatal, and it often takes considerable time to kill off parts of larger, established trees. Nevertheless, smaller trees and shrubs in difficult situations are nearly always killed. Your tree sounds very much like it has this infection, but all is not necessarily lost. Verticillium physically clogs the vasculature of the plant, so in warmer areas where water stress is more significant, and on sites where the pathogen is allowed to build up, it appears to be a more virulent pathogen. Locally, verticillium outbreaks in native maple stands nearly always affect only certain branches (small sectors of the root system are involved), and are coincident with exceptionally wet winter and/or dry summer conditions, which suggests that susceptibility has plenty to do with plant health, local root conditions, and probably also competing soil microflora (verticillium isn't the only microbe competing for space in a healthy soil ecosystem). In an exposed (sunny and windy) location without spring and summer irrigation, even in Vancouver, verticillium is a more serious problem. Nurseries are also the source of much introduced verticillium. Have you planted a new Japanese maple lately? See this previous thread .
Hi We have several juvenile acers that have arrived from china about 3 months ago. We've noticed some die-back (have been able to cope with that) and some other strange things... White bugs with fluffy bums that can jump. They metamorphose into black moths about 1.5cm across and 1cm long. Also now some of the leaves are turning yellow at the edges & dying off. Any ideas? Phil from Bristol, UK
