WE have exactly the same problem. There are 5 big leaf maples alongside our driveway and they all look unhappy. One in particular is brown in the top, all the way down to the trunk. We had the tree men here on Friday and are having them back. They are going to take the top off the tree and hopefully it will sprout from the trunk -- sort of pollarding in a big way. They have done this with a neighbours tree and it has come back very well. Another friend of ours had one split in two unexpectedly -- luckily no one was under it, so there is good reason to worry about these trees. We get that winter moth in the trees and right now the leaves are quite lacy with the larvae from the moths. There is no way we can control the moths, the trees are much too big. I believe though (without any expert telling me) that the past few summers have been very warm and dry, more so than usual, and the trees have been badly stressed. I've been complaining about this lousy summer, but perhaps there has been less hot weather and more rain so the trees might have a chance to survive. It is a worry though.

Drought. Not enough water. Humans should use their brains and notice when rainfall for months and years is inadequate and WATER their trees. Sprinklers and hoses with frequent application do wonders! WATER.

Trees everywhere here in Portland are dying left and right. Ppl just are not able to notice the most blatant weather facts. Clouds do not equal rain. It has to actually rain a lot, long and steady and repeat, for roots to get enough moisture.

Watering a tree and keeping it optimally healthy helps keep the tree less stressed which results in fewer predatory bugs and fewer opportunistic diseases.

I appreciate your comments gardengal. It would be impossible to water these trees manually -- our property has a LOT of mature maples, Doug Firs, Garry Oaks, etc. I think that we have a good underground system, once a newly planted tree gets its roots down well, it just grows phenomenally. We have one Garry Oak that is in distress plus these bigleaf Maples, and one or 2 DFirs. There has been a lot of building uphill from our place and I wonder if all of the blacktop and building has changed the underground stream system. If I want to hire a professional to evaluate the health of our trees, what qualifications do I ask for?
Cascadians, I totally agree that most people don't realize that cloudy days do not equate with rain. I have a rain gauge and am amazed by how little actual rainfall we have in the summertime. Despite our lousy grey weather this spring!

Yep, been hearing ppl complaining about the gloomy rainy summer here but I have a rain gauge too and there's nothing in it -- the caterpillar mist is less than a dewdrop and the warm sun evaporates that quickly. The folks in Washington State are so fortunate in that they've actually gotten some of the wet miraculous life-giving water.

The weatherman blog on KGW says for the last 7 months we've had way below-average rainfall and we're in a drought. Also the snowpack in the Cascades was below average. The thought of water rationing is horrifying to me with over 300 new baby swamp trees not yet established in my yard. I've been watering like a rainforest and everything is putting on a flush of autumn growth and many plants are beginning to look like they've "taken."

I spend every day worrying and praying that if water rationing does come, it's after these trees get established -- and that the PacNW never has to experience water rationing.

Have you all read the demographic forecast that says the PacNW population will DOUBLE by 2020? That's in just 13 years, unbelievable. The infill building in my neck of the woods is insane. That many more ppl are going to use a lot more water.

There are a lot of ppl here who have bigleaf maples and other natives in their yards that are dying. Ppl think these trees are used to summer drought but it's been more severe each summer for the last 9 years and then on top of it the last 7 months have been dry. If these trees were deeply and regularly watered they would be in much better shape to withstand this drought. Just the facts.

Cascadians, where do you think the water you are using to water your "300 new baby swamp trees" come from? Are you on a well? Do you have a "swamp" in your yard? If not, you are using the Oregon City water supply, drawing down the ground water table. It's probably a good thing your neighbors are not watering, so you can.

As you mention, with large numbers of people coming to the greater Portland area, it is important that we all do our part to conserve water so we don't have to ration. Particularly so if we are in a drought. Watering "like a rainforest" is not going to make it rain more.

BTW, what is a "swamp" tree? Do you mean trees that do well in a wetland like cottonwoods or willows?

This part of Oregon City, called the "toe of the mountain" (just a hill), was natural swampland before they finally allowed houses on it, with innumerable underground springs keeping it very wet and boggy in fall / winter and used to be spring. In May 2005 when I bought this house, there was 4' of standing water in the crawl space and in the yard which did not disappear until late August. The City sent Public Works out daily for months to help us deal with the water table. We had to raise everything about 2' so the root balls could breathe, and plant trees that love to slurp up water, trees that normally thrive in swampy conditions. Posted tons about this on GardenWeb, all archived. The city said to water a lot for 3 years to get roots established, then the roots would hit the water table and do their job of slurping out this stupendous amount of water. The inspector told us the water pressure would actually tip our house off the foundation if we didn't find some way to alleviate the amount of water accumulating (1998 manufactured home, 2300 sqft, on concrete slab but not tied down). Planted over 300 trees December 2005 and many since then, filling in and replacing ones that croaked.

As I posted above, many of these trees show signs of "taking" so the plan is working! Our neighbor to the south decided to put up a cedar fence and rented an auger and drilled lots of 2' deep holes this past weekend. He was astonished to see these holes fill quickly with water even though his surface grass has died due to lack of moisture. It's just a matter of the swamp trees being babied along the 1st 3 years so they stay alive and their roots grow and hit the water table and all problems solved.

Had innumerable arborists and geologists and consultants advise us. There are wells here but they were covered by the construction crews and the idiot neighbor to the east up the hill took a bulldozer and destroyed the entire irrigation system that powered these wells. This whole swamp used to be one person's property but then it was subdivided and no longer functions.

I had to dig 5 creeklets through the yard and put in large flagstones in deeper level places to run utility pumps to get water, but they have dried up this month due to drought.

It is so tragic to see beautiful large mature trees that have taken decades or centuries to attain their majestic status only to die without any watering by the humans around them in times of prolonged drought. That so many ppl do not appreciate and nurture these awesome trees and try to compensate for man's disruption of water flow and natural areas is sad and deprives future generations of the magnificence that once was abundant.

What a sterile, flat, depressing and barren planet man is rapidly ravaging toward. Future generations, if there are any, will look at pictures of old riparian forests and be awed at the resplendent beauty and horrified that their forebears did not see the value and let it all be destroyed.

Dotty, you ask about qualifications. The tree expert should be a certified aborist (I believe I.S.A. is the professional designation). Anyone who is certified will have the knowledge to diagnose problems and will be able to send in samples to a lab for analysis. From what I've read, Acer macrophyllum has a life span of up to 275 years but I'm wondering what the mean lifespan really is? Since the healthiest ones I've seen have been in relatively undistrubed ecosystems, where they are covered in mosses, and probably flourishing because of the microrhyzal interaction in their environment, I'm wondering if the ones we have on our properties are doomed to a shortened lifespan from the start.

Thanks Madrone. We are working with Bartlett Tree Service so I will ask them to check the maples for me. The one that is the worst has had a tough life -- the centre is burned out and the kids next door think it's a magic fort. Sapsuckers obviously have this on their trapline too. But, I have friends who had one not much better than this and they had it bucked off about 15' in the air and it is quite happy now. Perhaps I'll be lucky too.

Bigleaf maples are even native to parts of central Washington that receive less than 15" of precipitation and are very hot in summer. They respond to drought by dropping their leaves early in August or Sept. much in the same way vine maple does.

This summer has been cool and dank, where's the heat??? I think we're going into the next ice age.

I agree, Ian. It's been a very uncharacteristic summer around here. My fan has not gotten the workout it normally receives at this time of year:-) And while I continue to water, it is not with the same intensity as usual. Without the sun and heat present, moisture evaporation from the soil is reduced and things just don't dry out as fast. I could see some big savings in my water bill, except that I suspect September and October may have some surprises for us.

I'd have to assume Cascadians' location is far enough away from the Puget Sound area to be experiencing a different weather pattern. We broke a number of daily precipitation records in July and it finally stacked up to be one of the dampest on record.

Yep, Oregon City is way south of Puget Sound -- how I wish I had moved to the Washington / Canada border decades ago! More rain, more water, cooler, better gardening up north. You folks are sooooooo fortunate! No rain here, but clouds, have appreciated these clouds fervently. Certainly does help the water bill. But trees like rainwater better than tap water.

While we haven't had the record rain you have had in the Puget Sound, we did get some rain and it has been much cooler and cloudier than normal. So, while we have been quite dry with the clouds, you are right, gardengal, without the sun and heat, moisture evaporation IS reduced.

We have only had 4 days of over 90 deg. F temperatures so far.

There has been some leaf drop on the mature trees but most of the trees suffering are the new, young ones without much of a root system. Most of the mature big leaf maples in my vicinity (SE Portland) seem to be doing fine.

I am encouraged by the responses but no closer to having a answer. I don't think drought stress is the issue with these trees, when I think about the different locations at which I have seen this. I live in Olympia, which has had more days of rain than just about any other city this year! I am concerned about SOD, can't seem to find any info about how it would affect a bigleaf maple. I have a couple of calls in to tree guys and will post if I get a definitive answer.

Armillaria root rot really seems like a likely possibility. It is present in a lot of our soils and is encouraged by unusually heavy summer rainfall.

Any questions anyone has about Sudden Oak Death, you can direct to me. That's what I do for 40 hours a week, is look for it.

SOD has not been found in the wild in Washington. It has never yet been seen on bigleaf maple in WA, or on any of our native plants, whether in the wild, in landscapes, or in nurseries. The probability of your having it on your mature trees in your yard is essentially zero. Newly planted rhodies that the nursery brought in from CA or OR is a different story, but even there the chances are very slim.

There is a saying in medical diagnostics which applies here. When you hear hoofbeats, think of horses, not zebras. SOD would be even rarer than a zebra here. More like an okapi or something. I've heard of arborists telling their clients that their trees are dying of SOD but that's just plain irresponsible. Might as well say your tree has west nile virus.

SOD cannot be diagnosed in the field. I've been doing this for over a year and I can't say when I've found it. Only the plant pathology lab can make a definitive diagnosis, and the lab has to be licensed by the USDA to do the work. I think you can take leaf or twig samples in a sealed plastic baggie to the Master Gardeners and they'll send it on to WSU but I'm not sure about that.

In any case, SOD kills tanoaks and live oaks but that's about it. It has not been found on garry oaks. It can sicken and slowly kill rhodies. Most all other hosts simply get an icky leaf or twig blight that does not kill the plant. That includes bigleaf maples and doug firs. Frankly, for our native plants, it's just another leaf blight, and a very minor one at that. I see no cause for panic.

For more info on SOD than you can shake a stick at, see the link below. Bear in mind that their focus is California, where the tanoaks and live oaks are dying. The host list is quite long, but many of those plants have only been found positive for SOD once - in a CA forest surrounded by dying oaks, for instance, or in a European nursery. For instance, the only time doug fir has come up positive is in CA xmas tree farms surrounded by dying oaks. Here, it's basically a very rare disease of nursery rhodies, kalmias, and camellias. It would be like someone here getting malaria - not exactly a likely occurrence!

Every tree has a limited life span. 200 year old bigleaf maples are approaching the upper limit of their life span. All trees die and fall eventually. The symptoms described by Sarabera sound like verticillium wilt to me, for which there is no cure. You can prune out killed branches and see if the rest of the tree can shake it off. Verticillium likes soil that alternates between very wet and very dry, just like we get here!

Building and paving definitely affect water movement in and under the soil, and affect how much water tree roots get and when - usually by speeding up the flow so more water goes by in winter and less in summer. Disturbed soil holds less water than undisturbed soil too so trees dry out faster. We got plenty of rain this winter and the soil was definitely filled with as much water as it can hold, and the underground aquifers too. Probably not strictly drought stress but just a combination of extreme age, stress from urbanization, and verticillium taking advantage of wet/dry cycles. And, it's normal for them to start going into fall color and leaf drop in late summer when stressed.

You want an ISA certified arborist.

Here is a link that might be useful: California Oak Mortality Task Force

Reg, thank you for a sensible overview of the SOD situation. I'm all in favor of stopping the spread of plant diseases, but the amount of hysteria over SOD is a lot more than what it needs to be. Diseases and pests come and go as climate fluctuates throughout history. I think in the end SOD will run its course without killing off any species entirely, and be thought of as 'not a big deal' in a broader historical/biologcal context.

I can't wait to see what you learn about your maples. We lost one last year, but now have three others with brown leaves. I've been watering daily during the Summer, so I doubt it's too dry.

Nash Rambler in Lake Oswego, Oregon

Has anyone figured out what is happeneing to the maples in the pacific Northwest?

I know this thread is old but it is one of a few I could find on the subject.
I live in the Mt.Shasta area,we receive 75 to 80' of rain a year.Our climate is what's considered Mediterranean (6mo wet/6mo. dry) I first noticed my BLM
( actually all the BLM's,they are native to the area)was not happy around 06/07
around the same time that our weather pattern changed.The rainy period now extends into early June when it use to end sometime in early April. Rain on the
freshly sprouted leaves is causing a blueish gray fungus to cover the leaves,
the leaves dry out,fall to the ground,then a new set of leaves start to sprout
and it is snow time again.I thought it was systemic so I started burning the
dead leaves but it has not helped.Now you can pick out all the BLM's on the
mountain sides. I too am curious what this could be?????????????

It could be this.

Here is a link that might be useful: Maple -- Powdery Mildew

I also have a 50-60 yr. old BLM(Acer macrophyllum) that has finally died. It started a couple of years ago with the top dying out. I live south of Eugene, and my property sits on a southeast facing slope and we get plenty of rain and plenty of warmth and sun. I have another maple that sits about 75 feet from the dead one mentioned. It suffers from a root disease, but has thus survived periodically sluffing off dead limbs. Big Leaf Maples are susceptible to a lot of diseases, which make them an important aspect in micro-ecosystems like backyards. I believe my "dead" maple succombed to the same root disease as the still living maple tree. Although I am perplexed because the dead maple was the most robust-looking tree in our yard. Nice deep green leaves, big bushy canopy. Then, all of a sudden it croaked. The Sudden Oak Death disease is not noted for killing maples. Armillaria species of fungus is fairly common throughout the PNW. Nice to see people typing correctly, correct spelling etc...