This season started pretty encouraging with an excellent month of April, sunny and dry, which made the maples to have a healthy growth free from pseudomonas and associated die-back, everything looked very encouraging. Unfortunately things have turned very nasty during the summer with almost all the conditions listed in the Oregon State maple disease list affecting many of the maples in my garden. New this year is a heavy infestation of Metcalfa pruinosa which affects just about every plant (and weed) in the garden. Worst of all has been verticillium albo-atrum. Up to now the cases of verticillium had been anecdotal with most occurrences happening within the year of purchase. This time many trees of all ages and all around the garden have been either killed or heavily disfigured. Among the most disappointing losses I could mention: 10 years old A. davidii 'Rosalie', 7 years old A. tegmentosum, 7 years old A. diabolicum, 10 years old A. japonicum 'Vitifolium',......They all have been in the ground, in the same place, for many years. My garden being in pristine forest land I had assumed it to be mostly free from the fungus, but now I see I was wrong. Gomero
That is such sad news Gomero. You must be devastated to lose so many beautiful Acers. All you hard work.... We have also suffered losses this year of several mature trees and shrubs due to Honey fungus. It is very disheartening.
Gomero, I am so sorry to hear of the death of some of your precious large trees. Maple cultivation like you do is not for the indulgent and weak. Nature kills for reasons our grief cannot fathom. Time and focus on the beauty you still have so abundantly in your yard will help. You are such an incredibly generous man that it particularly hurts me to see someone giving like you hurt. All of us on this forum who know you as a friend grieve with you. Mike
So sorry to hear this. It is very difficult to loose trees, especially these beautiful maples that are so cared for and appreciated. I hope your fortunes change, no more losses! David
Gomero, not much that can be said. So sorry. I've written this year off, but your calamities dwarf ours here. Most of my losses have been young by comparison... Is there any common thread you can draw -- source, exposition, water flow -- between the trees? I've read about the Metcalfa infestations, but had no idea it was so serious. Is the nuclear option on the table, or are they throughout the neighborhood?
Sad news indeed, so sorry to hear it. I wish I could do something to help. Here's hoping this is the end of it, and next year will bring you better growing conditions.
Thank you everybody for the nice, empathetic comments, it helps ;-)) I really have no sure explanation, the only common threads I can think of are: - Drier than normal July & August. But this is common here and the entire garden is under automatic watering. - The heavy infestation of Metcalfa pruinosa. This is really new this year. It maybe that the two combined have weakened the trees making them more suceptible to all other pathogens. For the Metcalfa, I have contacted the French equivalent to the local agricultural extension in order to try to secure some parasitic wasps for next year. Gomero
hi i live near gomero but more in the west of france This summer wasn't particulary hot but it was really dry i have a small river in my garden and it gives a good humidity to most of my maples but the others have suffered even if they get water. I also got more dieback than usual i think that air humidity is an important matter for acers
This is not a pleasant task to come in after the fact and try to sort out what we may have been able to do to help a particular situation or a combination of factors that may have led to a terrible year. We went through a similar year three years ago with several container grown Maples, all between the ages of 8-15 years. For us the battle was that no matter how much water was being applied we still saw evidence of Tight Bark stunting terminal tips and then saw just how bad Verticillium alboatrum could rear its ugly head. Even with the pruning out of the affected and dying growth, we did not get much new replacement growth from just under the pruning cuts. Took more pruning and then by late Summer we saw some flushes of new growth but the damage had already been done. When a 7-12 foot tall Maple soon becomes a 3-4 footer just to try to save it, I think in terms of years lost but sometimes these plants will snap out of their doldrums and others seem to benefit from these misgivings. One thing that has been consistent with our container plants across the board is that with soil compaction, less aeration in the roots, we see more trouble develop and at a much faster rate than in more recently potted up plants. What has me a little perplexed is that Maples in a forest type soil are getting hit by Powdery Mildew. This is not a good sign to me at all. In moist Spring conditions, we expect to see some mildew with some of our more tender variegated forms but when green and red palmates also are affected, this is cause for concern. Yes, it has been suggested more than once that dry roots can lead to the Summer forms of Powdery Mildew but that is not the case with the more destructive Spring forms. I wonder how much oxygen is in the root zone as much of the time for container Maples giving them new soil seems to help them a great deal with the Spring forms of Powdery Mildew. I wonder if the forest soils might need more aeration, regardless of how little or how much water is being applied. The problem with the Maples that Gomero has had some trouble with is that each one of them has been known for a long time to be loaded with Verticillium alboatrum in their plant systems. It is a hard fact of life that when these plants stress we may see the fungus kill off limbs and large branches and feel that there was nothing we could do to stop it. One of the issues we have in a warm and dry climate that others in cooler and more moist conditions do not see nearly as readily and certainly not as rampant as we can get hurt by the fungus. Another observation I've had in the last few years around here is that several Maples have had much more Spider Mite activity that I can recall since the 70's drought years. Another case for some overhead watering in areas that are pretty much devoid of marine air during the Summer months. Gomero if there is anything I can do to help, do not hesitate to let me know. I really do feel for you and I also know there isn't a lot I can say that may make the situation better for you. Just remember that in some of the Maples we want to grow, even when we do pretty much everything right we can still see problems in these plants from the past crop up and really bite us. I wish it didn't happen but it does and when it does, very little can make us feel good about our attempts to grow these plants. All the best, Jim
Gomero, I, too, am sorry for your losses. I lost a few this year but nothing like you saw. In fact, this year I have seen almost explosive growth on a number of cultivars. We have had ample rain. But this will not be the case forever. We have had horrific droughts here in the past and will see them again. A reminder that none of us are far removed from the grasp of Mother Nature. My philosophy therefore is to enjoy it while you have it, and when its gone - find something better to try. Hope you can make lemonade of your lemons!!
Kaitan, it sounds like you didn't do too bad with all those floods that I heard about in Tenn. Thanks for posting this Gomero - Just knowing that this can happen (to the best of them) helps prepare for that inevitable bad year...
Gomero, I'm simply shocked and dismayed. You have my heartfelt sympathy. I must confess, I'm now really nervous about my own trees. I mean, if someone with your depth of knowledge who obviously bestows meticulous care on their trees can be dealt these types of losses... what chance do my trees have? But I know from "talking" with you on the forum that if anyone can bring a situation like yours back under control that you can. Cold comfort, I know, in the face of dead trees. But I expect you're even now fretting about the ones you still have. And as much as I wish this hadn't happened to you, please accept my gratitude for your sharing. I think all of us hope that by sharing our experiences we can help each other figure out the best way to care for these beauties so that others don't face the sadness you are currently facing, or at least, face it less often. That is, assuming that fine tuning the care we give can increase our trees' odds of success. In the vein of trying to find a silver lining, I found three previous points in this thread to be of interest: the ubiquitousness of verticillium, and the importance of humidity and aeration of the roots. I, too, suspect that the horse is out of the barn with verticillium and that it's simply everywhere. And for that reason we, all of us, need to beware of "stressors" for our trees. Further, I suspect that controlling those latter two things may be of more importance than any of us have previously suspected. Gomero, I wish good fortune toward you and your trees.
I wholeheartedly thank everybody for the nice words of encouragement. As Winterhaven and others correctly say, we must be aware that, no matter what we do, we can always be hit by disaster, this is ‘life’ for maple enthusiasts. Good practices will minimize the risk but will not make it to disappear. With experience one can easily spot those maples that will not ‘make it’ for sure and a good practice would call for trashing and replacing them (as MJH suggested in a parallel thread). However this is not enough since most of my losses to Verticillium were of previously healthy and vigorous growers. Gomero
Gomero, were any of them grown from seed? You mention diabolicum and tegmentosum. So, growing maples requires either a masochist or a Zen Master, eh? :) -E
Emery, They were both grown from seed. I agree ;-)) (I may add that it also requires a thick checkbook to keep replacing the dead ones) Gomero
Dear Friend So sorry to hear this. Disaster like you have described, seems to be due environmental conditions and thus, it is no much what you could do to prevent it. Regards, Carlos
Thanks Carlos. I have done some thinking and have come up with some hypothetical leads as to how the Verticillium fungus could be introduced into a garden other than in the potting soil or soil ball of the purchased maple. One possibility could be the mulch. I buy huge amounts of composted shredded wood (all types of wood) which I spread as mulch once a year. The question is: does the fungus survives OK the composting process? Another possibility is the home compost. I have a hot composting bin where I place all my organic kitchen waste (less meat) and then use (sparingly) the resulting compost in the mix when planting everything in the garden. In the kitchen waste there are a lot of waste coming from solanaceaes, like potatoes and tomatoes. However I am not sure as to the presence of the fungus in the fruits (tomato) or in the skin of tubercles (potatoes). All comments on this are welcomed since understanding and sorting out these issues is important for all of us. Gomero
To my mind composted bark would be well worth thorough investigation Some of the bark I buy over here looks to me to be much less well composted than others I have been suspicious of potential problems for some time, as I too buy quite alot (usually on an annual basis)
I should think bark/wood products derived from conifers would be Verticillium free as all gymnosperms are immune to verticillium wilt. Over here most of the bark type products are byproducts of the forestry industry which almost guarantees they are from conifers, fortunately. (Gomero, the following is mostly just conjecture, I am certainly not an expert on maple diseases, but you asked for all comments and, as you say, a discussion of all opinions and ideas is beneficial for all of us.) I understand that Verticillium albo-atrum can persist in the soil for over 15 years in a resting form, just waiting for the right conditions to attack a host, and, as Jim mentioned earlier in the thread, the plants can be already contaminated with it in their system, presumably also in a resting form, just waiting for the right conditions to attack. My guess is that the weather, or other unknown event, caused stress on these maples and that allowed the Verticillium to gain the upper hand in a perennial battle between the fungi and the trees. My philosophy is to assume that Verticillium is present to some degree in any soil, and maybe already in some of our trees, and is just one of those opportunist organisms waiting for its chance to thrive, which in this case would be a stressed or unhealthy maple. I think you hit the nail on the head previously when you said Just my 2 centimes, but hope it gives you something to think about.
Could be helpful to apply micorrhyzae, since they colonize roots and thus, make a "barrier" against pathogens?
today i observation one new variable,the maples with many flowers this spring are in strees condiition ,leaves off over 50%,metacalfa is present in platanoides Crimson sentry ,acer macrophillum and like every year in acer circinatum,the grown branch is many interesting,in my usda zone maples grown around 20cm /ears,genus palmatum around 10 cm/year ...this year 40-5o cm and 30-35 cm genus palmatum O.O!is possible that unusual many rain ,stimulate this problem?..of course many rain for usda zone 9b ;)
This year I have had an even worse season with a lot of maples affected by Verticillium with several precious ones dead by now. I have lost 12 and have about 20 affected but not dead. I'll show some instructive examples. The most regrettable loss is my only A. mandshuricum (first pic) which was a beautiful and healthy 10 year old, grown from seed. It was probably hit by the acute form that affects trees in the Spring since by mid-July it was completely gone (pic is from end July). The next pic (also end July) shows a 'Tiger Rose' where the disease seems to have been circumscribed to half of the tree. It may be saved (for now). The third pic (from end July) shows a 'Moonfire'. It is all dead now. Snakebarks (section Macranthe) are a case apart. None of my snakebarks seem to be able to pass the, roughly, 10 years mark. They all succumb to verticillium, no matter whether they are grafted or grown from seed. After those of last year, I have lost my gorgeous A. conspicuum 'Phoenix' which was about 9 years old and 3-4 meters high. I am attaching several pics of the bark since, with snakebarks, it is astonishing how you can track the disease progression. The parts of the bark with yellow stripes are still unaffected while the parts with the darker stripes have been infected. The tree is now gone with most of the buds dead as shown. Someone was asking recently in this forum why we do not see more mature snakebarks in gardens........., any hints? Gomero
Gomero, I wish I could do more for you, my friend, than just tell you how sorry I am to hear of your loss. I know how wounded I feel when I lose trees so I can empathize with your pain. It is hard indeed to lose old friends. Mike
Wow, that's hard. I'm so sorry to hear this bad news. I wonder if the V. albo-atrum can be transmitted in seed, awaiting some trigger to multiply. My pensylvanicum, also seed grown and about 8 years old, is exhibiting the tell-tale black this summer. best, -Emery